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[rmodels] UpdateModelAnimation() reviewed matrix-transpose, only once per bone #5244

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Merged
merged 1 commit into from
Oct 15, 2025
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[rmodels] UpdateModelAnimation() reviewed matrix-transpose, only once per bone #5244

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87 changes: 46 additions & 41 deletions src/rmodels.c
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Original file line number Diff line number Diff line change
Expand Up @@ -2352,54 +2352,59 @@ void UpdateModelAnimation(Model model, ModelAnimation anim, int frame)
Mesh mesh = model.meshes[m];
Vector3 animVertex = { 0 };
Vector3 animNormal = { 0 };
Matrix boneMatrix = { 0 };
Matrix InverseBoneMatrix = { 0 };
int boneId = 0;
int boneCounter = 0;
float boneWeight = 0.0;
bool updated = false; // Flag to check when anim vertex information is updated
const int vValues = mesh.vertexCount*3;

// Skip if missing bone data, causes segfault without on some models
if ((mesh.boneWeights == NULL) || (mesh.boneIds == NULL)) continue;

for (int vCounter = 0; vCounter < vValues; vCounter += 3)
{
mesh.animVertices[vCounter] = 0;
mesh.animVertices[vCounter + 1] = 0;
mesh.animVertices[vCounter + 2] = 0;
if (mesh.animNormals != NULL)
{
mesh.animNormals[vCounter] = 0;
mesh.animNormals[vCounter + 1] = 0;
mesh.animNormals[vCounter + 2] = 0;
}

// Iterates over 4 bones per vertex
for (int j = 0; j < 4; j++, boneCounter++)
{
boneWeight = mesh.boneWeights[boneCounter];
boneId = mesh.boneIds[boneCounter];

// Early stop when no transformation will be applied
if (boneWeight == 0.0f) continue;
animVertex = (Vector3){ mesh.vertices[vCounter], mesh.vertices[vCounter + 1], mesh.vertices[vCounter + 2] };
animVertex = Vector3Transform(animVertex,model.meshes[m].boneMatrices[boneId]);
mesh.animVertices[vCounter] += animVertex.x*boneWeight;
mesh.animVertices[vCounter+1] += animVertex.y*boneWeight;
mesh.animVertices[vCounter+2] += animVertex.z*boneWeight;
updated = true;

// Normals processing
// NOTE: We use meshes.baseNormals (default normal) to calculate meshes.normals (animated normals)
if ((mesh.normals != NULL) && (mesh.animNormals != NULL ))
{
animNormal = (Vector3){ mesh.normals[vCounter], mesh.normals[vCounter + 1], mesh.normals[vCounter + 2] };
animNormal = Vector3Transform(animNormal, MatrixTranspose(MatrixInvert(model.meshes[m].boneMatrices[boneId])));
mesh.animNormals[vCounter] += animNormal.x*boneWeight;
mesh.animNormals[vCounter + 1] += animNormal.y*boneWeight;
mesh.animNormals[vCounter + 2] += animNormal.z*boneWeight;
}
}
}
if ((mesh.boneWeights == NULL) || (mesh.boneIds == NULL)) continue;

// Iterates over 4 bones per vertex
for (int j = 0; j < 4; j++, boneCounter++)
{
boneWeight = mesh.boneWeights[boneCounter];
boneId = mesh.boneIds[boneCounter];

// Early stop when no transformation will be applied
if (boneWeight == 0.0f) continue;

boneMatrix = model.meshes[m].boneMatrices[boneId];
InverseBoneMatrix = MatrixTranspose(MatrixInvert(boneMatrix));

for (int vCounter = 0; vCounter < vValues; vCounter += 3)
{
mesh.animVertices[vCounter] = 0;
mesh.animVertices[vCounter + 1] = 0;
mesh.animVertices[vCounter + 2] = 0;
if (mesh.animNormals != NULL)
{
mesh.animNormals[vCounter] = 0;
mesh.animNormals[vCounter + 1] = 0;
mesh.animNormals[vCounter + 2] = 0;
}
animVertex = (Vector3){ mesh.vertices[vCounter], mesh.vertices[vCounter + 1], mesh.vertices[vCounter + 2] };
animVertex = Vector3Transform(animVertex, boneMatrix);
mesh.animVertices[vCounter] += animVertex.x*boneWeight;
mesh.animVertices[vCounter+1] += animVertex.y*boneWeight;
mesh.animVertices[vCounter+2] += animVertex.z*boneWeight;
updated = true;

// Normals processing
// NOTE: We use meshes.baseNormals (default normal) to calculate meshes.normals (animated normals)
if ((mesh.normals != NULL) && (mesh.animNormals != NULL))
{
animNormal = (Vector3){ mesh.normals[vCounter], mesh.normals[vCounter + 1], mesh.normals[vCounter + 2] };
animNormal = Vector3Transform(animNormal, InverseBoneMatrix);
mesh.animNormals[vCounter] += animNormal.x*boneWeight;
mesh.animNormals[vCounter + 1] += animNormal.y*boneWeight;
mesh.animNormals[vCounter + 2] += animNormal.z*boneWeight;
}
}
}

if (updated)
{
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