From dfc94f64d1e1db5231a68e8ea968378df16f2292 Mon Sep 17 00:00:00 2001
From: Arrangemonk <34814431+Arrangemonk@users.noreply.github.com>
Date: Fri, 31 Oct 2025 20:43:27 +0100
Subject: [PATCH] =?UTF-8?q?Revert=20"UpdateModelAnimation=20does=20matrixt?=
 =?UTF-8?q?ranspose(matrixinvert)=20only=20once=20per=E2=80=A6"=20(#5322)?=
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This reverts commit e3a562ab57a9fa4a9dbaa3d5ffb67f31c25a4a36.
---
 src/rmodels.c | 79 ++++++++++++++++++++++++---------------------------
 1 file changed, 37 insertions(+), 42 deletions(-)

diff --git a/src/rmodels.c b/src/rmodels.c
index 3c904c396..ed86fb19a 100644
--- a/src/rmodels.c
+++ b/src/rmodels.c
@@ -2352,8 +2352,6 @@ 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;
@@ -2361,50 +2359,47 @@ void UpdateModelAnimation(Model model, ModelAnimation anim, int frame)
         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;
+        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];
+        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;
+            }
 
-            // Early stop when no transformation will be applied
-            if (boneWeight == 0.0f) continue;
+            // Iterates over 4 bones per vertex
+            for (int j = 0; j < 4; j++, boneCounter++)
+            {
+                boneWeight = mesh.boneWeights[boneCounter];
+                boneId = mesh.boneIds[boneCounter];
 
-            boneMatrix = model.meshes[m].boneMatrices[boneId];
-            InverseBoneMatrix = MatrixTranspose(MatrixInvert(boneMatrix));
+                // 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;
 
-			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;
-				}
-			}
-		}
+                // 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 (updated)
         {