void Start()
{
Stopwatch sw = new Stopwatch();
sw.Start();
Scene scene = new Scene(true);
bvhScene = new BVHScene(scene.triangles, scene.vertices);
Debug.Log("bvhScene.triangles.Count = " + bvhScene.triangles.Count);
Debug.Log(" ================================ ");
var bvhData = new CPU_BVHData(bvhScene);
CPU_SBVHBuilder.Build(bvhData);
Debug.Log("bvhData.triangles.Count = " + bvhData.triIndices.Count);
Debug.Log(" ================================ ");
// debug gpu bvh
GPU_BVHData gpuData = new GPU_BVHData().Generate(bvhData);
Debug.Log("gpuData.nodes.Count = " + gpuData.nodes.Count);
Debug.Log("gpuData.woopTris.Count = " + gpuData.woopTris.Count);
Debug.Log("gpuData.triIndices.Count = " + gpuData.triIndices.Count);
root = bvhData.root;
sw.Stop();
string log = "Build successfully, time: " + sw.ElapsedMilliseconds + " ms";
Debug.Log(log);
}
public override void OnInspectorGUI()
{
var tracer = target as TracerBehaviour;
bool pressGenerateBVH = GUILayout.Button("Rebuild BVH", GUILayout.ExpandWidth(true));
if (pressGenerateBVH)
{
var scene = new Scene(true);
var bvhScene = new BVHScene(scene.triangles, scene.vertices);
var cpuBVH = new CPU_BVHData(bvhScene);
CPU_SBVHBuilder.Build(cpuBVH);
SaveBVH(tracer, cpuBVH);
}
//bool pressTest = GUILayout.Button("Log Test", GUILayout.ExpandWidth(true));
//if (pressTest)
//{
// Debug.Log(tracer.gpuBVH.nodes.Count);
// Debug.Log(tracer.gpuBVH.nodes[1]);
//}
DrawProperty("useCachedBVH");
DrawProperty("spps");
DrawProperty("tracingShader");
DrawProperty("skyboxTex");
DrawProperty("sun");
serializedObject.ApplyModifiedProperties();
}
private void woopifyTri(CPU_BVHData bvh, int triIdx)
{
// fetch the 3 vertex indices of this triangle
Vector3Int vtxInds = bvh.scene.triangles[bvh.triIndices[triIdx]];
Vector3 v0 = bvh.scene.vertices[vtxInds.x];
Vector3 v1 = bvh.scene.vertices[vtxInds.y];
Vector3 v2 = bvh.scene.vertices[vtxInds.z];
// regular triangles (for debugging only)
_debug[0] = new Vector4(v0.x, v0.y, v0.z, 0.0f);
_debug[1] = new Vector4(v1.x, v1.y, v1.z, 0.0f);
_debug[2] = new Vector4(v2.x, v2.y, v2.z, 0.0f);
Matrix4x4 mtx = new Matrix4x4();
// compute edges and transform them with a matrix
mtx.SetColumn(0, MathUtils.Swizzle(v0 - v2)); // sets matrix column 0 equal to a Vec4f(Vec3f, 0.0f )
mtx.SetColumn(1, MathUtils.Swizzle(v1 - v2, 0.0f));
mtx.SetColumn(2, MathUtils.Swizzle(Vector3.Cross(v0 - v2, v1 - v2), 0.0f));
mtx.SetColumn(3, MathUtils.Swizzle(v2, 1.0f));
mtx = Matrix4x4.Inverse(mtx);
/// m_woop[3] stores 3 transformed triangle edges
_woop[0] = new Vector4(mtx[2, 0], mtx[2, 1], mtx[2, 2], -mtx[2, 3]); // elements of 3rd row of inverted matrix
_woop[1] = mtx.GetRow(0);
_woop[2] = mtx.GetRow(1);
}
private CPU_SBVHBuilder(CPU_BVHData bvhData)
{
_bvhData = bvhData;
_refStack = new List <PrimitiveRef>();
_rightBounds = new List <AABB>();
int rightBoundsCount = Mathf.Max(_bvhData.scene.triangles.Count, N_SPATIAL_BINS) - 1;
for (int i = 0; i < rightBoundsCount; i++)
{
_rightBounds.Add(AABB.New());
}
}
// Start is called before the first frame update
void Start()
{
if (gpuBVH == null)
{
Debug.Log("No cached BVH data found, building BVH now.");
_theScene = new Scene(true);
var bvhScene = new BVHScene(_theScene.triangles, _theScene.vertices);
var cpuBVH = new CPU_BVHData(bvhScene);
CPU_SBVHBuilder.Build(cpuBVH);
gpuBVH = new GPU_BVHData().Generate(cpuBVH);
}
else
{
_theScene = new Scene(true);
Debug.Log("Using cached BVH data.");
}
// bind texture2darray
var diffuseTexLen = _theScene.diffuseTextures.Count;
if (_theScene.diffuseTextures.Count > 0)
{
var tex = _theScene.diffuseTextures[0];
_diffuseTextures = new Texture2DArray(tex.width, tex.height, diffuseTexLen, tex.format, true);
for (int i = 0; i < diffuseTexLen; i++)
{
Graphics.CopyTexture(_theScene.diffuseTextures[i], 0, _diffuseTextures, i);
}
}
// bvh
CreateComputeBuffer(ref _nodesBuffer, gpuBVH.nodes, 16);
CreateComputeBuffer(ref _woopTrisBuffer, gpuBVH.woopTris, 16);
CreateComputeBuffer(ref _triIndicesBuffer, gpuBVH.triIndices, 4);
// per vertex
CreateComputeBuffer(ref _verticesBuffer, _theScene.vertices, 12);
CreateComputeBuffer(ref _normalsBuffer, _theScene.normals, 12);
CreateComputeBuffer(ref _uv0sBuffer, _theScene.uv0s, 8);
// per triangle
CreateComputeBuffer(ref _trianglesBuffer, _theScene.triangles, 12);
CreateComputeBuffer(ref _materialsBuffer, _theScene.materials, 144);
CreateComputeBuffer(ref _matIdxBuffer, _theScene.matIndices, 4);
}
private static void SaveBVH(TracerBehaviour tracer, CPU_BVHData cpuBVH)
{
var cacheDir = "Assets/Cache/BVH/";
if (!System.IO.Directory.Exists(cacheDir))
{
System.IO.Directory.CreateDirectory(cacheDir);
}
var path = cacheDir + EditorSceneManager.GetActiveScene().name + "_BVH.prefab";
var dataObj = new GameObject("__BVHData__");
var cachedBVH = dataObj.AddComponent <GPU_BVHData>();
cachedBVH.Generate(cpuBVH);
var prefabRoot = PrefabUtility.SaveAsPrefabAsset(dataObj, path);
DestroyImmediate(dataObj);
tracer.gpuBVH = prefabRoot.GetComponent <GPU_BVHData>();
}
public static void Build(CPU_BVHData bvhData)
{
var builder = new CPU_SBVHBuilder(bvhData);
builder.Build();
}
public GPU_BVHData Generate(CPU_BVHData cpuData)
{
nodes = new List <Vector4>();
woopTris = new List <Vector4>();
triIndices = new List <int>();
Stack <StackEntry> stack = new Stack <StackEntry>();
stack.Push(new StackEntry(cpuData.root, 0));
AABB[] cbox = new AABB[2];
int[] cidx = new int[2];
Vector4[] zero4 = new Vector4[4] {
new Vector4(), new Vector4(), new Vector4(), new Vector4()
};
nodes.AddRange(zero4);
while (stack.Count > 0)
{
var cur = stack.Pop();
for (int i = 0; i < 2; i++)
{
var child = cur.node.GetChildNode(i);
cbox[i] = child.bounds;
if (!child.IsLeaf())
{
cidx[i] = nodes.Count /* / nodeOffsetSizeDiv */;
stack.Push(new StackEntry(child, nodes.Count));
nodes.AddRange(zero4);
continue;
}
LeafNode leaf = child as LeafNode;
cidx[i] = ~woopTris.Count;
for (int j = leaf.triangleStart; j < leaf.triangleEnd; j++)
{
woopifyTri(cpuData, j);
woopTris.Add(_woop[0]);
woopTris.Add(_woop[1]);
woopTris.Add(_woop[2]);
triIndices.Add(cpuData.triIndices[j]);
triIndices.Add(0); // 对齐索引，好查找
triIndices.Add(0);
}
// 用来标记属于该叶节点的三角形末端
woopTris.Add(new Vector4(1e20f, 0, 0, 0));
triIndices.Add(0);
}
int dstIdx = cur.idx;
nodes[dstIdx] = new Vector4(cbox[0].min.x, cbox[0].max.x, cbox[0].min.y, cbox[0].max.y);
nodes[dstIdx + 1] = new Vector4(cbox[1].min.x, cbox[1].max.x, cbox[1].min.y, cbox[1].max.y);
nodes[dstIdx + 2] = new Vector4(cbox[0].min.z, cbox[0].max.z, cbox[1].min.z, cbox[1].max.z);
nodes[dstIdx + 3] = new Vector4(cidx[0], cidx[1], 0, 0);
}
return(this);
}
