This commit will switch blender to use tangent space generated within

the two files mikktspace.h and mikktspace.c. These are standalone files
which can be redistributed into any other application and regenerate the
same tangent spaces. The implementation is independent of the ordering
of faces and the vertex ordering of faces.

1 files changed, 16 insertions, 2 deletions

diff --git a/source/blender/gpu/intern/gpu_material.c b/source/blender/gpu/intern/gpu_material.c
index cb28d0dbe47..fb8c7465a4d 100644
--- a/source/blender/gpu/intern/gpu_material.c
+++ b/source/blender/gpu/intern/gpu_material.c
@@ -894,6 +894,7 @@ static void do_material_tex(GPUShadeInput *shi)
 	int tex_nr, rgbnor, talpha;
 	int init_done = 0, iBumpSpacePrev;
 	GPUNodeLink *vNorg, *vNacc, *fPrevMagnitude;
+	int iFirstTimeNMap=1;
 
 	GPU_link(mat, "set_value", GPU_uniform(&one), &stencil);
 
@@ -902,7 +903,7 @@ static void do_material_tex(GPUShadeInput *shi)
 	GPU_link(mat, "texco_object", GPU_builtin(GPU_INVERSE_VIEW_MATRIX),
 		GPU_builtin(GPU_INVERSE_OBJECT_MATRIX),
 		GPU_builtin(GPU_VIEW_POSITION), &texco_object);
-	GPU_link(mat, "texco_tangent", GPU_attribute(CD_TANGENT, ""), &texco_tangent);
+	//GPU_link(mat, "texco_tangent", GPU_attribute(CD_TANGENT, ""), &texco_tangent);
 	GPU_link(mat, "texco_global", GPU_builtin(GPU_INVERSE_VIEW_MATRIX),
 		GPU_builtin(GPU_VIEW_POSITION), &texco_global);
 
@@ -1037,7 +1038,20 @@ static void do_material_tex(GPUShadeInput *shi)
 							GPU_link(mat, "mtex_negate_texnormal", tnor, &tnor);
 
 						if(mtex->normapspace == MTEX_NSPACE_TANGENT)
-							GPU_link(mat, "mtex_nspace_tangent", GPU_attribute(CD_TANGENT, ""), shi->vn, tnor, &newnor);
+						{
+							if(iFirstTimeNMap!=0)
+							{
+								// use unnormalized normal (this is how we bake it - closer to gamedev)
+								GPUNodeLink *vNegNorm;
+								GPU_link(mat, "vec_math_negate", GPU_builtin(GPU_VIEW_NORMAL), &vNegNorm);
+								GPU_link(mat, "mtex_nspace_tangent", GPU_attribute(CD_TANGENT, ""), vNegNorm, tnor, &newnor);
+								iFirstTimeNMap = 0;
+							}
+							else	// otherwise use accumulated perturbations
+							{
+								GPU_link(mat, "mtex_nspace_tangent", GPU_attribute(CD_TANGENT, ""), shi->vn, tnor, &newnor);
+							}
+						}
 						else
 							newnor = tnor;