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GenMeshTangents Fix (#1877)

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* GenMeshTangents Fix

* GenMeshTangents Fix - Comment Update

* GenMeshTangents Fix - Comment Update final

* Code Style Changes

* Code Style Changes Final
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630Studios 2021-07-16 15:14:13 -05:00 committed by GitHub
parent 56cab4b6a9
commit 9aaf7a8057
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GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 24 additions and 9 deletions
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33
src/models.c
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@ -2652,11 +2652,20 @@ BoundingBox GetMeshBoundingBox(Mesh mesh)
// Implementation base don: https://answers.unity.com/questions/7789/calculating-tangents-vector4.html
void GenMeshTangents(Mesh *mesh)
{
if (mesh->tangents == NULL) mesh->tangents = (float *)RL_MALLOC(mesh->vertexCount*4*sizeof(float));
else TRACELOG(LOG_WARNING, "MESH: Tangents data already available, re-writting");
Vector3 *tan1 = (Vector3 *)RL_MALLOC(mesh->vertexCount*sizeof(Vector3));
Vector3 *tan2 = (Vector3 *)RL_MALLOC(mesh->vertexCount*sizeof(Vector3));
if (mesh->tangents == NULL)
{
mesh->tangents = (float*)RL_MALLOC(mesh->vertexCount*4*sizeof(float));
}
else
{
rlUnloadVertexBuffer(mesh->vboId[SHADER_LOC_VERTEX_TANGENT]);
RL_FREE(mesh->tangents);
mesh->tangents = (float*)RL_MALLOC(mesh->vertexCount*4*sizeof(float));
}
Vector3* tan1 = (Vector3*)RL_MALLOC(mesh->vertexCount*sizeof(Vector3));
Vector3* tan2 = (Vector3*)RL_MALLOC(mesh->vertexCount*sizeof(Vector3));
for (int i = 0; i < mesh->vertexCount; i += 3)
{
@ -2683,7 +2692,7 @@ void GenMeshTangents(Mesh *mesh)
float t2 = uv3.y - uv1.y;
float div = s1*t2 - s2*t1;
float r = (div == 0.0f)? 0.0f : 1.0f/div;
float r = (div == 0.0f) ? 0.0f : 1.0f/div;
Vector3 sdir = { (t2*x1 - t1*x2)*r, (t2*y1 - t1*y2)*r, (t2*z1 - t1*z2)*r };
Vector3 tdir = { (s1*x2 - s2*x1)*r, (s1*y2 - s2*y1)*r, (s1*z2 - s2*z1)*r };
@ -2704,20 +2713,20 @@ void GenMeshTangents(Mesh *mesh)
Vector3 tangent = tan1[i];
// TODO: Review, not sure if tangent computation is right, just used reference proposed maths...
#if defined(COMPUTE_TANGENTS_METHOD_01)
#if defined(COMPUTE_TANGENTS_METHOD_01)
Vector3 tmp = Vector3Subtract(tangent, Vector3Scale(normal, Vector3DotProduct(normal, tangent)));
tmp = Vector3Normalize(tmp);
mesh->tangents[i*4 + 0] = tmp.x;
mesh->tangents[i*4 + 1] = tmp.y;
mesh->tangents[i*4 + 2] = tmp.z;
mesh->tangents[i*4 + 3] = 1.0f;
#else
#else
Vector3OrthoNormalize(&normal, &tangent);
mesh->tangents[i*4 + 0] = tangent.x;
mesh->tangents[i*4 + 1] = tangent.y;
mesh->tangents[i*4 + 2] = tangent.z;
mesh->tangents[i*4 + 3] = (Vector3DotProduct(Vector3CrossProduct(normal, tangent), tan2[i]) < 0.0f)? -1.0f : 1.0f;
#endif
mesh->tangents[i*4 + 3] = (Vector3DotProduct(Vector3CrossProduct(normal, tangent), tan2[i]) < 0.0f) ? -1.0f : 1.0f;
#endif
}
RL_FREE(tan1);
@ -2725,6 +2734,12 @@ void GenMeshTangents(Mesh *mesh)
// Load a new tangent attributes buffer
mesh->vboId[SHADER_LOC_VERTEX_TANGENT] = rlLoadVertexBuffer(mesh->tangents, mesh->vertexCount*4*sizeof(float), false);
rlEnableVertexArray(mesh->vaoId);
rlSetVertexAttribute(4, 4, RL_FLOAT, 0, 0, 0);
rlEnableVertexAttribute(4);
rlDisableVertexArray();
TRACELOG(LOG_INFO, "MESH: Tangents data computed for provided mesh");
}