private bool CompareLODs(LODGroup a, LODGroup b)
{
if (a.GetLODs() == null || b.GetLODs() == null || a.GetLODs().Length != b.GetLODs().Length)
{
return false;
}
MeshFilter[] componentsInChildren = a.GetComponentsInChildren<MeshFilter>();
MeshFilter[] componentsInChildren2 = b.GetComponentsInChildren<MeshFilter>();
if (componentsInChildren.Length != componentsInChildren2.Length)
{
return false;
}
for (int i = 0; i < componentsInChildren.Length; i++)
{
if (componentsInChildren[i].sharedMesh != componentsInChildren2[i].sharedMesh)
{
return false;
}
}
return true;
}
public static void GenerateLODs(LODGroup lodGroup, HashSet <Mesh> newMeshes = null)
{
LOD[] lods = lodGroup.GetLODs();
// Cleanup
for (int i = 1; i < lods.Length; i++)
{
foreach (Renderer renderer in lods[i].renderers)
{
if (renderer != null)
{
Object.DestroyImmediate(renderer.gameObject);
}
}
}
if (newMeshes == null)
{
newMeshes = new HashSet <Mesh>();
}
// Assign LOD0
Renderer[] renderers = lodGroup.GetComponentsInChildren <Renderer>();
lods[0].renderers = renderers;
Dictionary <Mesh, ConnectedMesh> uniqueMeshes = new Dictionary <Mesh, ConnectedMesh>();
foreach (Renderer renderer in renderers)
{
if (renderer is MeshRenderer meshRenderer)
{
MeshFilter meshFilter = renderer.gameObject.GetComponent <MeshFilter>();
if (meshFilter)
{
Mesh mesh = meshFilter.sharedMesh;
if (!uniqueMeshes.ContainsKey(mesh))
{
uniqueMeshes.TryAdd(mesh, m => UnityConverter.ToSharedMesh(m).ToConnectedMesh());
}
}
}
else if (renderer is SkinnedMeshRenderer skinnedMeshRenderer)
{
Mesh mesh = skinnedMeshRenderer.sharedMesh;
if (!uniqueMeshes.ContainsKey(mesh))
{
uniqueMeshes.TryAdd(mesh, m => UnityConverter.ToSharedMesh(m).ToConnectedMesh());
}
}
}
foreach (KeyValuePair <Mesh, ConnectedMesh> uniqueMesh in uniqueMeshes)
{
uniqueMesh.Value.MergePositions(0.0001);
uniqueMesh.Value.MergeAttributes();
uniqueMesh.Value.Compact();
}
SceneDecimator sceneDecimator = new SceneDecimator();
sceneDecimator.Initialize(uniqueMeshes.Values);
// Build LODs
for (int i = 1; i < lods.Length; i++)
{
// Decimates gradually
sceneDecimator.DecimateToRatio(lods[i - 1].screenRelativeTransitionHeight);
Dictionary <Mesh, Mesh> optimizedMeshes = uniqueMeshes.ToDictionary(x => x.Key, x => x.Value.ToSharedMesh().ToUnityMesh());
List <Renderer> lodRenderers = new List <Renderer>();
foreach (Renderer renderer in renderers)
{
if (renderer is MeshRenderer meshRenderer)
{
MeshFilter meshFilter = renderer.gameObject.GetComponent <MeshFilter>();
if (meshFilter)
{
GameObject gameObject = new GameObject(renderer.gameObject.name + "_LOD" + i);
gameObject.transform.parent = renderer.transform;
gameObject.transform.localPosition = UnityEngine.Vector3.zero;
gameObject.transform.localRotation = UnityEngine.Quaternion.identity;
gameObject.transform.localScale = UnityEngine.Vector3.one;
MeshRenderer mr = gameObject.AddComponent <MeshRenderer>();
MeshFilter mf = gameObject.AddComponent <MeshFilter>();
Mesh originalMesh = meshFilter.sharedMesh;
Mesh optimizedMesh = optimizedMeshes[originalMesh]; // Todo : Don't create new mesh if it's the same (tri count);
optimizedMesh.name = originalMesh.name + "_LOD" + i;
mr.sharedMaterials = meshRenderer.sharedMaterials;
mf.sharedMesh = optimizedMesh;
newMeshes.Add(optimizedMesh);
lodRenderers.Add(mr);
}
}
else if (renderer is SkinnedMeshRenderer skinnedMeshRenderer)
{
GameObject gameObject = new GameObject(renderer.gameObject.name + "_LOD" + i);
gameObject.transform.parent = renderer.transform;
gameObject.transform.localPosition = UnityEngine.Vector3.zero;
gameObject.transform.localRotation = UnityEngine.Quaternion.identity;
gameObject.transform.localScale = UnityEngine.Vector3.one;
SkinnedMeshRenderer smr = gameObject.AddComponent <SkinnedMeshRenderer>();
smr.bones = skinnedMeshRenderer.bones;
smr.rootBone = skinnedMeshRenderer.rootBone;
Mesh originalMesh = skinnedMeshRenderer.sharedMesh;
Mesh optimizedMesh = optimizedMeshes[originalMesh]; // Todo : Don't create new mesh if it's the same (tri count);
optimizedMesh.name = originalMesh.name + "_LOD" + i;
smr.sharedMaterials = skinnedMeshRenderer.sharedMaterials;
smr.sharedMesh = optimizedMesh;
optimizedMesh.bindposes = originalMesh.bindposes; // Copy poses
newMeshes.Add(optimizedMesh);
lodRenderers.Add(smr);
}
}
///Debug.Log($"LOD{i} created with {lodRenderers.Count} renderers at {100f * lods[i - 1].screenRelativeTransitionHeight}% poly ratio");
lods[i].renderers = lodRenderers.ToArray();
}
lodGroup.SetLODs(lods);
}