public static void ForceIvyGrowth(IvyGraph graph, IvyProfile ivyProfile, Vector3 newPos, Vector3 newNormal)
        {
            newPos -= graph.seedPos; // convert to local space

            var closestRoot = graph.roots[0];

            var lastNode   = closestRoot.nodes[closestRoot.nodes.Count - 1];
            var growVector = newPos - lastNode.p;

            var newNode = new IvyNode();

            newNode.p  = newPos;
            newNode.g  = (0.5f * lastNode.g + 0.5f * growVector.normalized).normalized;
            newNode.c  = -newNormal;
            newNode.s  = lastNode.s + growVector.magnitude;
            newNode.cS = lastNode.cS + growVector.magnitude;
            newNode.fS = 0f;
            newNode.cl = true;

            closestRoot.nodes.Add(newNode);
            closestRoot.useCachedBranchData = false;
            closestRoot.useCachedLeafData   = false;

            var cache = IvyRoot.GetMeshCacheFor(closestRoot);

            cache.debugLineSegmentsList.Add(lastNode.p + graph.seedPos);
            cache.debugLineSegmentsList.Add(newPos + graph.seedPos);
            cache.debugLineSegmentsArray = cache.debugLineSegmentsList.ToArray();

            if (graph.generateMeshDuringGrowth)
            {
                IvyMesh.GenerateMesh(graph, ivyProfile);
            }
        }
        public static void ForceRandomIvyBranch(IvyGraph graph, IvyProfile ivyProfile)
        {
            var randomRoot   = graph.roots[0];
            var randomNode   = randomRoot.nodes[Random.Range(0, randomRoot.nodes.Count)];
            var randomLength = randomNode.cS + Mathf.Lerp(ivyProfile.minLength * 1.5f, ivyProfile.maxLength, Random.value);

            TryGrowIvyBranch(graph, ivyProfile, randomRoot, randomNode, randomLength);
        }
コード例 #3
0
        static void RefreshMeshObject(MeshFilter mf, IvyProfile ivyProfile)
        {
#if UNITY_EDITOR
            SetStaticEditorFlag(mf.gameObject, StaticEditorFlags.BatchingStatic, ivyProfile.markMeshAsStatic);
            SetStaticEditorFlag(mf.gameObject, StaticEditorFlags.ContributeGI, ivyProfile.useLightmapping);
#endif
            var branchTrans = mf.transform;
            branchTrans.localPosition = Vector3.zero;
            branchTrans.localRotation = Quaternion.identity;
            branchTrans.localScale    = Vector3.one;
        }
        public static IvyGraph MergeVisibleIvyGraphs(IvyBehavior ivyBehavior, IvyProfile ivyProfile, bool rebuildMesh = true)
        {
            var graphsToMerge = ivyBehavior.ivyGraphs.Where(graph => graph.isVisible).ToList();

            if (graphsToMerge == null || graphsToMerge.Count == 0)
            {
                return(null);
            }

            var mainGraph = graphsToMerge[0];

            for (int i = 0; i < ivyBehavior.ivyGraphs.Count; i++)
            {
                var graph = ivyBehavior.ivyGraphs[i];
                if (!graph.isVisible || graph == mainGraph)
                {
                    continue;
                }

                // convert merged graph's localPos to mainGraph's localPos
                foreach (var root in graph.roots)
                {
                    foreach (var node in root.nodes)
                    {
                        node.p += graph.seedPos - mainGraph.seedPos;
                    }
                }
                mainGraph.roots.AddRange(graph.roots);

                if (graph.rootGO != null)
                {
                    DestroyObject(graph.rootGO);
                }
                TryToDestroyMeshes(ivyBehavior, graph);

                ivyBehavior.ivyGraphs.Remove(graph);
                i--;
            }

            if (rebuildMesh)
            {
                Undo.RegisterFullObjectHierarchyUndo(mainGraph.rootGO, "Hedera > Merge Visible");
                IvyMesh.GenerateMesh(mainGraph, ivyProfile, ivyProfile.useLightmapping, true);
                AssetDatabase.SaveAssets();
            }

            return(mainGraph);
        }
コード例 #5
0
        public static void InitOrRefreshRoot(IvyGraph ivyGraph, IvyProfile ivyProfile)
        {
            if (ivyGraph.rootGO == null)
            {
                ivyGraph.rootGO = new GameObject("HederaObject");
                ivyGraph.rootGO.transform.SetParent(ivyGraph.rootBehavior);
            }
#if UNITY_EDITOR
            SetStaticEditorFlag(ivyGraph.rootGO, StaticEditorFlags.BatchingStatic, ivyProfile.markMeshAsStatic);
            SetStaticEditorFlag(ivyGraph.rootGO, StaticEditorFlags.ContributeGI, ivyProfile.useLightmapping);
#endif
            var rootTrans = ivyGraph.rootGO.transform;
            rootTrans.position   = ivyGraph.seedPos;
            rootTrans.rotation   = Quaternion.identity;
            rootTrans.localScale = Vector3.one;
            ivyGraph.rootGO.name = string.Format(ivyProfile.namePrefix, ivyGraph.roots.Count, ivyGraph.seedPos);
        }
        static bool TryGrowIvyBranch(IvyGraph graph, IvyProfile ivyProfile, IvyRoot root, IvyNode fromNode, float forceMinLength = -1f)
        {
            //weight depending on ratio of node length to total length
            float weight          = 1f; //Mathf.PerlinNoise( fromNode.localPos.x + fromNode.lengthCumulative, fromNode.length + fromNode.localPos.y + fromNode.localPos.z); // - ( Mathf.Cos( fromNode.length / root.nodes[root.nodes.Count-1].length * 2.0f * Mathf.PI) * 0.5f + 0.5f );
            var   nearbyRootCount = graph.roots.Where(r => (r.nodes[0].p - fromNode.p).sqrMagnitude < ivyProfile.ivyStepDistance * ivyProfile.ivyStepDistance).Count();

            if (forceMinLength <= 0f)
            {
                if (graph.roots.Count >= ivyProfile.maxBranchesTotal ||
                    nearbyRootCount > ivyProfile.branchingProbability * 2.5f ||
                    root.childCount > ivyProfile.branchingProbability * 3.5f ||
                    root.nodes.Count < 3 ||
                    root.parents > ivyProfile.branchingProbability * 9f ||
                    ivyProfile.maxLength - fromNode.cS < ivyProfile.minLength ||
                    Random.value * Mathf.Clamp(weight, 0f, 1f - ivyProfile.branchingProbability) > ivyProfile.branchingProbability
                    )
                {
                    return(false);
                }
            }

            //new ivy node
            IvyNode newRootNode = new IvyNode();

            newRootNode.p  = fromNode.p;
            newRootNode.g  = Vector3.Lerp(fromNode.g, Vector3.up, 0.5f).normalized;
            newRootNode.c  = fromNode.c;
            newRootNode.s  = 0.0f;
            newRootNode.cS = forceMinLength > 0f ? 0f : fromNode.cS;
            newRootNode.fS = forceMinLength > 0f ? 0f : fromNode.fS;
            newRootNode.cl = true;

            //new ivy root
            IvyRoot newRoot = new IvyRoot();

            newRoot.nodes.Add(newRootNode);
            newRoot.isAlive        = true;
            newRoot.parents        = root.parents + 1;
            newRoot.forceMinLength = forceMinLength;

            graph.roots.Add(newRoot);
            root.childCount++;
            return(true);
        }
コード例 #7
0
        static void CreateIvyMeshObject(IvyGraph graph, IvyProfile profile, Mesh mesh, bool isLeaves = false)
        {
            var PartObj = new GameObject("HederaMesh");

            PartObj.transform.parent        = graph.rootGO.transform;
            PartObj.transform.localPosition = Vector3.zero;

            if (!isLeaves)
            {
                graph.branchMF            = PartObj.AddComponent <MeshFilter>();
                graph.branchMF.sharedMesh = mesh;
                graph.branchR             = PartObj.AddComponent <MeshRenderer>();
            }
            else
            {
                graph.leafMF            = PartObj.AddComponent <MeshFilter>();
                graph.leafMF.sharedMesh = mesh;
                graph.leafR             = PartObj.AddComponent <MeshRenderer>();
            }
        }
        public static IvyGraph SeedNewIvyGraph(IvyProfile ivyProfile, Vector3 seedPos, Vector3 primaryGrowDir, Vector3 adhesionVector, Transform root, bool generateMeshPreview = false)
        {
            var graph = new IvyGraph();

            graph.roots.Clear();
            graph.seedPos    = seedPos;
            graph.seedNormal = adhesionVector;
            graph.generateMeshDuringGrowth = generateMeshPreview;
            graph.rootBehavior             = root;

            IvyNode tmpNode = new IvyNode();

            tmpNode.p  = Vector3.zero; //seedPos;
            tmpNode.g  = primaryGrowDir;
            tmpNode.c  = adhesionVector;
            tmpNode.s  = 0.0f;
            tmpNode.cS = 0f;
            tmpNode.fS = 0.0f;
            tmpNode.cl = true;

            IvyRoot tmpRoot = new IvyRoot();

            tmpRoot.nodes.Add(tmpNode);
            tmpRoot.isAlive = true;
            graph.isGrowing = true;
            tmpRoot.parents = 0;
            graph.roots.Add(tmpRoot);

            if (graph.generateMeshDuringGrowth)
            {
                IvyMesh.GenerateMesh(graph, ivyProfile);
#if UNITY_EDITOR
                Undo.RegisterCreatedObjectUndo(graph.rootGO, "Hedera > Paint Ivy");
#endif
            }

            return(graph);
        }
コード例 #9
0
        public static void GenerateMesh(IvyGraph ivyGraph, IvyProfile ivyProfile, bool doUV2s = false, bool forceGeneration = false)
        {
            // avoid GC allocations by reusing static lists
            verticesAll.Clear();
            texCoordsAll.Clear();
            trianglesAll.Clear();
            leafVerticesAll.Clear();
            leafUVsAll.Clear();
            leafTrianglesAll.Clear();
            leafColorsAll.Clear();

            // the main mesh generation actually happens here; if it can't generate a mesh, then stop
            if (!GenerateMeshData(ivyGraph, ivyProfile, forceGeneration))
            {
                return;
            }
            ivyGraph.dirtyUV2s = !doUV2s;

            InitOrRefreshRoot(ivyGraph, ivyProfile);
            var myAsset = IvyCore.GetDataAsset(ivyGraph.rootGO);

            // Branch mesh debug
            // Debug.Log( "branchVertices: " + verticesAll.Count );
            // Debug.Log( "branchTris: " + string.Join(", ", trianglesAll.Select( tri => tri.ToString() ).ToArray()) );
            // foreach ( var vert in verticesAll ) {
            //     Debug.DrawRay( vert + ivyGraph.seedPos, Vector3.up, Color.cyan, 1f, false );
            // }

            if (ivyProfile.ivyBranchSize < 0.0001f)
            {
                if (ivyGraph.branchMF != null)
                {
                    IvyCore.DestroyObject(ivyGraph.branchMF.gameObject);
                }
                IvyCore.TryDestroyMesh(ivyGraph.branchMeshID, myAsset, true);
            }
            else
            {
                CheckMeshDataAsset(ref ivyGraph.branchMeshID, myAsset, ivyProfile.meshCompress);
                branchMesh = myAsset.meshList[ivyGraph.branchMeshID];

                if (ivyGraph.branchMF == null || ivyGraph.branchR == null)
                {
                    CreateIvyMeshObject(ivyGraph, ivyProfile, branchMesh, false);
                }
                RefreshMeshObject(ivyGraph.branchMF, ivyProfile);

                branchMesh.Clear();
                ivyGraph.branchMF.name             = ivyGraph.rootGO.name + "_Branches";
                ivyGraph.branchR.shadowCastingMode = ivyProfile.castShadows;
                ivyGraph.branchR.receiveShadows    = ivyProfile.receiveShadows;
                branchMesh.name = ivyGraph.branchMF.name;
                branchMesh.SetVertices(verticesAll);
                branchMesh.SetUVs(0, texCoordsAll);
                if (ivyProfile.useLightmapping && doUV2s)
                {
                    PackBranchUV2s(ivyGraph);
                }
                branchMesh.SetTriangles(trianglesAll, 0);
                branchMesh.RecalculateBounds();
                branchMesh.RecalculateNormals();
                branchMesh.RecalculateTangents();
                #if UNITY_2017_1_OR_NEWER && UNITY_EDITOR
                MeshUtility.Optimize(branchMesh);
                #endif
                ivyGraph.branchMF.sharedMesh = branchMesh;
#if UNITY_EDITOR
                ivyGraph.branchR.sharedMaterial = ivyProfile.branchMaterial != null ? ivyProfile.branchMaterial : AssetDatabase.GetBuiltinExtraResource <Material>("Default-Diffuse.mat");
#else
                ivyGraph.branchR.sharedMaterial = ivyProfile.branchMaterial;
#endif
            }

            // Leaves mesh debug
            // Debug.Log( "leafVertices: " + ivyGraph.leafVertices.Count );
            // Debug.Log( "leafTris: " + string.Join(", ", ivyGraph.leafTriangles.Select( tri => tri.ToString() ).ToArray()) );

            // don't do leaf mesh if it's unnecessary
            if (ivyProfile.leafProbability < 0.001f)
            {
                if (ivyGraph.leafMF != null)
                {
                    IvyCore.DestroyObject(ivyGraph.leafMF.gameObject);
                }
                IvyCore.TryDestroyMesh(ivyGraph.leafMeshID, myAsset, true);
            }
            else
            {
                CheckMeshDataAsset(ref ivyGraph.leafMeshID, myAsset, ivyProfile.meshCompress);
                leafMesh = myAsset.meshList[ivyGraph.leafMeshID];

                if (ivyGraph.leafMF == null || ivyGraph.leafR == null)
                {
                    CreateIvyMeshObject(ivyGraph, ivyProfile, leafMesh, true);
                }
                RefreshMeshObject(ivyGraph.leafMF, ivyProfile);

                leafMesh.Clear();
                ivyGraph.leafMF.name             = ivyGraph.rootGO.name + "_Leaves";
                ivyGraph.leafR.shadowCastingMode = ivyProfile.castShadows;
                ivyGraph.leafR.receiveShadows    = ivyProfile.receiveShadows;
                leafMesh.name = ivyGraph.leafMF.name;
                leafMesh.SetVertices(leafVerticesAll);
                leafMesh.SetUVs(0, leafUVsAll);
                if (ivyProfile.useLightmapping && doUV2s)
                {
                    PackLeafUV2s(ivyGraph);
                }
                leafMesh.SetTriangles(leafTrianglesAll, 0);
                if (ivyProfile.useVertexColors)
                {
                    leafMesh.SetColors(leafColorsAll);
                }
                leafMesh.RecalculateBounds();
                leafMesh.RecalculateNormals();
                leafMesh.RecalculateTangents();
#if UNITY_2017_1_OR_NEWER && UNITY_EDITOR
                MeshUtility.Optimize(leafMesh);
#endif
                ivyGraph.leafMF.sharedMesh = leafMesh;
#if UNITY_EDITOR
                ivyGraph.leafR.sharedMaterial = ivyProfile.leafMaterial != null ? ivyProfile.leafMaterial : AssetDatabase.GetBuiltinExtraResource <Material>("Default-Diffuse.mat");
#else
                ivyGraph.leafR.sharedMaterial = ivyProfile.leafMaterial;
#endif
            }
            // EditorUtility.SetDirty( myAsset );
            // AssetDatabase.SaveAssets();
            // AssetDatabase.ImportAsset( AssetDatabase.GetAssetPath(myAsset) );
        }
コード例 #10
0
        static bool GenerateMeshData(IvyGraph ivyGraph, IvyProfile ivyProfile, bool forceGeneration = false)
        {
            var p = ivyProfile;

            //branches
            foreach (var root in ivyGraph.roots)
            {
                var cache = IvyRoot.GetMeshCacheFor(root);
                if (root.useCachedBranchData && !forceGeneration)
                {
                    combinedTriangleIndices.Clear();
                    cache.triangles.ForEach(localIndex => combinedTriangleIndices.Add(localIndex + verticesAll.Count));
                    trianglesAll.AddRange(combinedTriangleIndices);

                    verticesAll.AddRange(cache.vertices);
                    texCoordsAll.AddRange(cache.texCoords);
                    continue;
                }
                root.useCachedBranchData = true;

                //process only roots with more than one node
                if (root.nodes.Count < 2)
                {
                    continue;
                }

                cache.vertices.Clear();
                cache.texCoords.Clear();
                cache.triangles.Clear();

                //branch diameter depends on number of parents AND branch taper
                float local_ivyBranchDiameter = 1.0f / Mathf.Lerp(1f, 1f + root.parents, ivyProfile.branchTaper);

                // smooth the line... which increases points a lot
                allPoints = root.nodes.Select(node => node.p).ToList();
                var useThesePoints = allPoints;
                if (ivyProfile.branchSmooth > 1)
                {
                    SmoothLineCatmullRomNonAlloc(allPoints, smoothPoints, ivyProfile.branchSmooth);
                    useThesePoints = smoothPoints;
                }

                // generate simplified points for each root, to make it less wavy AND save tris
                if (!root.isAlive && ivyProfile.branchOptimize > 0f)
                {
                    newPoints.Clear();
                    newPoints.AddRange(SimplificationHelpers.Simplify <Vector3>(
                                           useThesePoints,
                                           (vec1, vec2) => vec1 == vec2,
                                           (vec) => vec.x,
                                           (vec) => vec.y,
                                           (vec) => vec.z,
                                           ivyProfile.branchOptimize * ivyProfile.ivyStepDistance * 0.5f,
                                           false
                                           ));
                    useThesePoints = newPoints;
                }

                // I'm not sure why there's this bug when we use Catmull Rom + line simplify, but let's do this hacky fix
                // if ( ivyProfile.branchSmooth > 1 && ivyProfile.branchOptimize > 0f ) {
                //     useThesePoints.ForEach( delegate(Vector3 point) {
                //         if ( float.IsInfinity(point.x) ) {point.x = 0f;}
                //         if ( float.IsInfinity(point.y) ) {point.y = 0f;}
                //         if ( float.IsInfinity(point.z) ) {point.z = 0f;}
                //     } );
                // }

                for (int n = 0; n < useThesePoints.Count; n++)
                {
                    if (verticesAll.Count >= 65531)
                    {
                        Debug.LogWarning("Hedera: ending branch generation early, reached ~65536 vertex limit on mesh " + ivyGraph.seedPos + "... but this could technically be solved in Unity 2017.3+ or later with 32-bit index formats for meshes? The exercise is left to the reader.");
                        break;
                    }
                    cache.meshSegments = n + 1;

                    //weight depending on ratio of node length to total length
                    float taper = 1f * n / useThesePoints.Count;
                    taper = Mathf.Lerp(1f, (1f - taper) * taper, ivyProfile.branchTaper);

                    //create trihedral vertices... TODO: let user specify how many sides?
                    Vector3 up    = Vector3.down;
                    Vector3 basis = Vector3.Normalize(n < useThesePoints.Count - 1 ? useThesePoints[n + 1] - useThesePoints[n] : -(useThesePoints[n] - useThesePoints[n - 1]));
                    // Debug.DrawLine( newPoints[node+1] + ivyGraph.seedPos, newPoints[node] + ivyGraph.seedPos, Color.cyan, 5f, false);

                    int   edges = 3;                        // TODO: finish this, make it configurable
                    float texV  = (n % 2 == 0 ? 1f : 0.0f); // vertical UV tiling
                    for (int b = 0; b < edges; b++)
                    {
                        // generate vertices
                        if (b == 0)
                        {
                            branchVertBasis[b] = Vector3.Cross(up, basis).normalized *Mathf.Max(0.001f, local_ivyBranchDiameter * p.ivyBranchSize * taper) + useThesePoints[n];
                        }
                        else
                        {
                            branchVertBasis[b] = RotateAroundAxis(branchVertBasis[0], useThesePoints[n], basis, 6.283f * b / edges);
                        }
                        cache.vertices.Add(branchVertBasis[b]);

                        // generate UVs
                        cache.texCoords.Add(new Vector2(1f * b / (edges - 1), texV));

                        // add triangles
                        // AddTriangle(root, 4, 1, 5);
                        // AddTriangle(root, 5, 1, 2);

                        // TODO: finish this
                    }

                    if (n == 0)   // start cap
                    {
                        if (taper > 0f)
                        {
                            AddTriangle(cache, 1, 2, 3);
                        }
                        continue;
                    }

                    AddTriangle(cache, 4, 1, 5);
                    AddTriangle(cache, 5, 1, 2);

                    AddTriangle(cache, 5, 2, 6);
                    AddTriangle(cache, 6, 2, 3);

                    AddTriangle(cache, 6, 3, 1);
                    AddTriangle(cache, 6, 1, 4);

                    if (n == useThesePoints.Count - 1 && taper > 0f) // end cap
                    {
                        AddTriangle(cache, 3, 2, 1);
                    }
                }

                combinedTriangleIndices.Clear();
                cache.triangles.ForEach(localIndex => combinedTriangleIndices.Add(localIndex + verticesAll.Count));
                trianglesAll.AddRange(combinedTriangleIndices);

                verticesAll.AddRange(cache.vertices);
                texCoordsAll.AddRange(cache.texCoords);
            }

            if (ivyProfile.ivyLeafSize <= 0.001f || ivyProfile.leafProbability <= 0.001f)
            {
                return(true);
            }

            //create leafs
            allLeafPoints.Clear();
            foreach (var root in ivyGraph.roots)
            {
                // don't bother on small roots
                if (root.nodes.Count <= 2)
                {
                    root.useCachedLeafData = false;
                    continue;
                }
                var cache = IvyRoot.GetMeshCacheFor(root);

                // use cached mesh data for leaves only if (a) we're supposed to, and (b) if not using vertex colors OR vertex colors seem valid
                if (root.useCachedLeafData && !forceGeneration && (!ivyProfile.useVertexColors || cache.leafVertices.Count == cache.leafVertexColors.Count))
                {
                    combinedTriangleIndices.Clear();
                    cache.leafTriangles.ForEach(index => combinedTriangleIndices.Add(index + leafVerticesAll.Count));
                    leafTrianglesAll.AddRange(combinedTriangleIndices);

                    allLeafPoints.AddRange(cache.leafPoints);
                    leafVerticesAll.AddRange(cache.leafVertices);
                    leafUVsAll.AddRange(cache.leafUVs);
                    if (ivyProfile.useVertexColors)
                    {
                        leafColorsAll.AddRange(cache.leafVertexColors);
                    }
                    continue;
                }
                root.useCachedLeafData = true;
                cache.leafPoints.Clear();
                cache.leafVertices.Clear();
                cache.leafUVs.Clear();
                cache.leafTriangles.Clear();
                cache.leafVertexColors.Clear();

                // simple multiplier, just to make it a more dense
                for (int i = 0; i < 1; ++i)
                {
                    var leafPositions = GetAllSamplePosAlongRoot(root, p.ivyLeafSize);

                    // for(int n=0; n<root.nodes.Count; n++)
                    foreach (var kvp in leafPositions)
                    {
                        if (leafVerticesAll.Count >= 65530)
                        {
                            Debug.LogWarning("Hedera: ending leaf generation early, reached ~65536 vertex limit on mesh " + ivyGraph.seedPos + "... but this could technically be solved in Unity 2017.3+ or later with 32-bit index formats for meshes? The exercise is left to the reader.");
                            break;
                        }

                        int     n          = kvp.Value;
                        Vector3 newLeafPos = kvp.Key;
                        var     node       = root.nodes[n];

                        // // do not generate a leaf on the first few nodes
                        // if ( n <= 1 ) { // || n >= root.nodes.Count
                        //     continue;
                        // }

                        // probability of leaves on the ground is increased
                        float groundedness = Vector3.Dot(Vector3.down, node.c.normalized);
                        if (groundedness < -0.02f)
                        {
                            groundedness -= 0.1f;
                            groundedness *= 3f;
                        }
                        else
                        {
                            groundedness = (groundedness - 0.25f) * 0.5f;
                        }
                        groundedness *= ivyProfile.leafSunlightBonus * p.leafProbability;

                        // don't spawn a leaf on top of another leaf
                        bool  badLeafPos  = false;
                        float leafSqrSize = p.ivyLeafSize * p.ivyLeafSize * Mathf.Clamp(1f - p.leafProbability - groundedness, 0.01f, 2f);
                        for (int f = 0; f < allLeafPoints.Count; f++)
                        {
                            if (Vector3.SqrMagnitude(allLeafPoints[f] - newLeafPos) < leafSqrSize)
                            {
                                badLeafPos = true;
                                break;
                            }
                        }
                        if (badLeafPos)
                        {
                            continue;
                        }

                        IvyNode previousNode     = root.nodes[Mathf.Max(0, n - 1)];
                        float   randomSpreadHack = 0.25f;
                        if (n <= 1 || n == root.nodes.Count - 1)
                        {
                            randomSpreadHack = 0f;
                        }

                        // randomize leaf probability // guarantee a leaf on the first or last node
                        if ((Random.value + groundedness > 1f - p.leafProbability) || randomSpreadHack == 0f)
                        {
                            cache.leafPoints.Add(node.p);
                            allLeafPoints.Add(node.p);

                            //center of leaf quad
                            Vector3 up     = (newLeafPos - previousNode.p).normalized;
                            Vector3 right  = Vector3.Cross(up, node.c);
                            Vector3 center = newLeafPos - node.c.normalized * 0.05f + (up * Random.Range(-1f, 1f) + right * Random.Range(-1f, 1f)) * randomSpreadHack * p.ivyLeafSize;

                            //size of leaf
                            float sizeWeight = 1.5f - (Mathf.Abs(Mathf.Cos(2.0f * Mathf.PI)) * 0.5f + 0.5f);
                            float leafSize   = p.ivyLeafSize * sizeWeight + Random.Range(-p.ivyLeafSize, p.ivyLeafSize) * 0.1f + (p.ivyLeafSize * groundedness);
                            leafSize = Mathf.Max(0.01f, leafSize);

                            Quaternion facing = node.c.sqrMagnitude < 0.001f ? Quaternion.identity : Quaternion.LookRotation(Vector3.Lerp(-node.c, Vector3.up, Mathf.Clamp01(0.68f - Mathf.Abs(groundedness)) * ivyProfile.leafSunlightBonus), Random.onUnitSphere);
                            AddLeafVertex(cache, center, new Vector3(-1f, 1f, 0f), leafSize, facing);
                            AddLeafVertex(cache, center, new Vector3(1f, 1f, 0f), leafSize, facing);
                            AddLeafVertex(cache, center, new Vector3(-1f, -1f, 0f), leafSize, facing);
                            AddLeafVertex(cache, center, new Vector3(1f, -1f, 0f), leafSize, facing);

                            cache.leafUVs.Add(new Vector2(1.0f, 1.0f));
                            cache.leafUVs.Add(new Vector2(0.0f, 1.0f));
                            cache.leafUVs.Add(new Vector2(1.0f, 0.0f));
                            cache.leafUVs.Add(new Vector2(0.0f, 0.0f));

                            if (ivyProfile.useVertexColors)
                            {
                                var randomColor = ivyProfile.leafVertexColors.Evaluate(Random.value);
                                cache.leafVertexColors.Add(randomColor);
                                cache.leafVertexColors.Add(randomColor);
                                cache.leafVertexColors.Add(randomColor);
                                cache.leafVertexColors.Add(randomColor);
                            }

                            // calculate normal of the leaf tri, and make it face outwards
                            // var normal = GetNormal(
                            //     ivyGraph.leafVertices[ivyGraph.leafVertices.Count - 2],
                            //     ivyGraph.leafVertices[ivyGraph.leafVertices.Count - 4],
                            //     ivyGraph.leafVertices[ivyGraph.leafVertices.Count - 3]
                            // );
                            // if ( Vector3.Dot( normal, node.adhesionVector) < 0f) {
                            //    AddLeafTriangle(ivyGraph, 2, 4, 3);
                            //    AddLeafTriangle(ivyGraph, 3, 1, 2);
                            // } else {
                            AddLeafTriangle(cache, 1, 3, 4);
                            AddLeafTriangle(cache, 4, 2, 1);
                            // }
                        }
                    }
                    combinedTriangleIndices.Clear();
                    cache.leafTriangles.ForEach(index => combinedTriangleIndices.Add(index + leafVerticesAll.Count));
                    leafTrianglesAll.AddRange(combinedTriangleIndices);

                    leafVerticesAll.AddRange(cache.leafVertices);
                    leafUVsAll.AddRange(cache.leafUVs);
                    if (ivyProfile.useVertexColors)
                    {
                        leafColorsAll.AddRange(cache.leafVertexColors);
                    }
                }
            }
            return(true);
        }
        static Vector3 ComputeAdhesion(Vector3 pos, IvyProfile ivyProfile)
        {
            Vector3 adhesionVector = Vector3.zero;

            float minDistance = ivyProfile.maxAdhesionDistance;

            // find nearest colliders
            var nearbyColliders = Physics.OverlapSphere(pos, ivyProfile.maxAdhesionDistance, ivyProfile.collisionMask, QueryTriggerInteraction.Ignore);

            // find closest point on each collider
            foreach (var col in nearbyColliders)
            {
                Vector3 closestPoint = pos + Vector3.down * ivyProfile.maxAdhesionDistance * 1.1f;
                // ClosestPoint does not work on non-convex mesh colliders so let's just pick the closest vertex
                if (col is MeshCollider && !((MeshCollider)col).convex)
                {
                    // if we haven't already cached mesh vertices, or it's a bad cache for some reason, then re-cache it
                    var mesh = ((MeshCollider)col).sharedMesh;
                    if (!adhesionMeshCache.ContainsKey(mesh))
                    {
                        adhesionMeshCache.Add(mesh, mesh.vertices);
                    }

                    // check for a close-enough vertex
                    float sqrMeshDistance = ivyProfile.maxAdhesionDistance * ivyProfile.maxAdhesionDistance * 4f;
                    for (int i = 0; i < adhesionMeshCache[mesh].Length; i++)
                    {
                        if (Vector3.SqrMagnitude(pos - col.transform.TransformPoint(adhesionMeshCache[mesh][i])) < sqrMeshDistance)
                        {
                            closestPoint    = col.transform.TransformPoint(adhesionMeshCache[mesh][i]);
                            sqrMeshDistance = Vector3.SqrMagnitude(pos - closestPoint);
                        }
                    }
                    // closestPoint = col.transform.TransformPoint( ((MeshCollider)col).sharedMesh.vertices.OrderBy( vert => Vector3.SqrMagnitude(pos - col.transform.TransformPoint(vert)) ).FirstOrDefault() );

                    // try to get surface normal towards nearest vertex
                    var meshColliderHit = new RaycastHit();
                    if (col.Raycast(new Ray(pos, closestPoint - pos), out meshColliderHit, ivyProfile.maxAdhesionDistance))
                    {
                        closestPoint = pos - meshColliderHit.normal * meshColliderHit.distance;
                    }
                    //Debug.Log($"Mesh collider not convex: {col.gameObject.name}");
                } // ClosestPoint doesn't work on TerrainColliders either...
                else if (col is TerrainCollider)
                {
                    // based on cache of TerrainColliders, search surrounding points until we find a close enough position
                    var terrain = colliderToTerrain[(TerrainCollider)col];
                    closestPoint   = pos;
                    closestPoint.y = terrain.SampleHeight(closestPoint);
                    Vector3 closestSearchPoint = closestPoint;
                    Vector3 currentSearchPoint = Vector3.zero;

                    for (int i = 0; i < terrainSearchDisc.Length; i++)
                    {
                        currentSearchPoint   = closestPoint + terrainSearchDisc[i] * ivyProfile.maxAdhesionDistance;
                        currentSearchPoint.y = terrain.SampleHeight(currentSearchPoint);
                        if (Vector3.SqrMagnitude(pos - currentSearchPoint) < Vector3.SqrMagnitude(pos - closestSearchPoint))
                        {
                            closestSearchPoint = currentSearchPoint;
                            // close enough, early out
                            if (Vector3.SqrMagnitude(pos - currentSearchPoint) < ivyProfile.ivyStepDistance * ivyProfile.ivyStepDistance)
                            {
                                break;
                            }
                        }
                    }

                    currentSearchPoint = closestSearchPoint + Vector3.down * 0.25f;
                    var terrainRayHit = new RaycastHit();
                    if (Physics.Raycast(pos, currentSearchPoint - pos, out terrainRayHit, minDistance, ivyProfile.collisionMask, QueryTriggerInteraction.Ignore))
                    {
                        closestPoint = pos - terrainRayHit.normal * Vector3.Distance(closestSearchPoint, pos);
                    }
                }
                else
                {
                    closestPoint = col.ClosestPoint(pos);
                }

                // see if the distance is closer than the closest distance so far
                float distance = Vector3.Distance(pos, closestPoint);
                if (distance < minDistance)
                {
                    minDistance     = distance;
                    adhesionVector  = (closestPoint - pos).normalized;
                    adhesionVector *= 1.0f - distance / ivyProfile.maxAdhesionDistance; //distance dependent adhesion vector
                    // close enough, early out
                    if (Vector3.SqrMagnitude(pos - closestPoint) < ivyProfile.ivyStepDistance * ivyProfile.ivyStepDistance)
                    {
                        //break;
                    }
                }
            }
            return(adhesionVector);
        }
        public static void GrowIvyStep(IvyGraph graph, IvyProfile ivyProfile)
        {
            // if there are no longer any live roots, then we're dead
            if (graph.isGrowing)
            {
                graph.isGrowing = graph.roots.Where(root => root.isAlive).Count() > 0;
            }
            if (!graph.isGrowing)
            {
                return;
            }

            //lets grow
            foreach (var root in graph.roots)
            {
                //process only roots that are alive
                if (!root.isAlive)
                {
                    continue;
                }

                IvyNode lastNode = root.nodes[root.nodes.Count - 1];

                //let the ivy die, if the maximum float length is reached
                if (lastNode.cS > ivyProfile.maxLength || (lastNode.cS > Mathf.Max(root.forceMinLength, ivyProfile.minLength) && lastNode.fS > ivyProfile.maxFloatLength))
                {
                    // Debug.LogFormat("root death! cum dist: {0:F2}, floatLength {1:F2}", lastNode.lengthCumulative, lastNode.floatingLength);
                    root.isAlive = false;
                    SmoothGaussianAdhesion(root);
                    continue;
                }

                //grow vectors: primary direction, random influence, and adhesion of scene objectss

                //primary vector = weighted sum of previous grow vectors plus a little bit upwards
                Vector3 primaryVector = Vector3.Normalize(lastNode.g * 2f + Vector3.up);

                //random influence plus a little upright vector
                Vector3 exploreVector = lastNode.p - root.nodes[0].p;
                if (exploreVector.magnitude > 1f)
                {
                    exploreVector = exploreVector.normalized;
                }
                exploreVector *= Mathf.PingPong(root.nodes[0].p.sqrMagnitude * root.parents + lastNode.cS * 0.69f, 1f);
                Vector3 randomVector = (Random.onUnitSphere * 0.5f + exploreVector).normalized;

                //adhesion influence to the nearest triangle = weighted sum of previous adhesion vectors
                Vector3 adhesionVector = ComputeAdhesion(lastNode.p + graph.seedPos, ivyProfile);
                if (adhesionVector.sqrMagnitude <= 0.01f)
                {
                    adhesionVector = lastNode.c;
                }

                //compute grow vector
                Vector3 growVector = ivyProfile.ivyStepDistance *
                                     Vector3.Normalize(
                    primaryVector * ivyProfile.primaryWeight
                    + randomVector * Mathf.Max(0.01f, ivyProfile.randomWeight)
                    + adhesionVector * ivyProfile.adhesionWeight
                    );

                //gravity influence
                Vector3 gravityVector = ivyProfile.ivyStepDistance * Vector3.down * ivyProfile.gravityWeight;
                //gravity depends on the floating length
                gravityVector *= Mathf.Pow(lastNode.fS / ivyProfile.maxFloatLength, 0.7f);

                //next possible ivy node

                //climbing state of that ivy node, will be set during collision detection
                bool climbing = false;

                //compute position of next ivy node
                Vector3 newPos = lastNode.p + growVector + gravityVector;

                //combine alive state with result of the collision detection, e.g. let the ivy die in case of a collision detection problem
                Vector3 adhesionFromRaycast = adhesionVector;

                // convert newPos to world position, just for the collision calc
                newPos      += graph.seedPos;
                root.isAlive = root.isAlive && ComputeCollision(0.01f, lastNode.p + graph.seedPos, ref newPos, ref climbing, ref adhesionFromRaycast, ivyProfile.collisionMask);
                newPos      -= graph.seedPos;

                //update grow vector due to a changed newPos
                growVector = newPos - lastNode.p - gravityVector;

                // +graph.seedPos to convert back to world space
                var cache = IvyRoot.GetMeshCacheFor(root);
                cache.debugLineSegmentsList.Add(lastNode.p + graph.seedPos);
                cache.debugLineSegmentsList.Add(newPos + graph.seedPos);
                // cache line segments
                cache.debugLineSegmentsArray = cache.debugLineSegmentsList.ToArray();

                //create next ivy node
                IvyNode newNode = new IvyNode();

                newNode.p  = newPos;
                newNode.g  = (0.5f * lastNode.g + 0.5f * growVector.normalized).normalized;
                newNode.c  = adhesionVector; //Vector3.Lerp(adhesionVector, adhesionFromRaycast, 0.5f);
                newNode.s  = lastNode.s + (newPos - lastNode.p).magnitude;
                newNode.cS = lastNode.cS + (newPos - lastNode.p).magnitude;
                newNode.fS = climbing ? 0.0f : lastNode.fS + (newPos - lastNode.p).magnitude;
                newNode.cl = climbing;

                root.nodes.Add(newNode);
                root.useCachedBranchData = false;
                root.useCachedLeafData   = false;

                if (!root.isAlive)
                {
                    SmoothGaussianAdhesion(root);
                }

                var randomNode = root.nodes[Random.Range(0, root.nodes.Count)];
                if (TryGrowIvyBranch(graph, ivyProfile, root, randomNode))
                {
                    break;
                }
            }
        }