Improved bump mapping patch by M.G. Kishalmi (lmg) and M.S. Mikkelsen (sparky).

Many thanks to them!

For comparison, see here:
http://kishalmi.servus.at/3D/bumpcode/

Based on algorithm in: Mikkelsen M. S.: Simulation of Wrinkled Surfaces Revisited.
http://jbit.net/~sparky/sfgrad_bump/mm_sfgrad_bump.pdf

This fixes bugs:
#24591: Artefacts/strange normal mapping when anti-aliasing is on
#24735: Error at the Normal function.
#24962: Normals are not calculated correctly if anti-aliasing is off
#25103: Weird artefacts in Normal

This will break render compatibility a bit, but fixing this bugs would have also
done that, so in this case it should be acceptable.

Patch committed with these modifications:
* Bump method Old/3-Tap/5-Tap option in UI, 3-Tap is default
* Only compute normal perturbation vectors when needed
* Fix some middle of block variable definitions for MSVC

1 files changed, 10 insertions, 3 deletions

diff --git a/source/blender/makesrna/intern/rna_material.c b/source/blender/makesrna/intern/rna_material.c
index ba2cea3defd..f8de8bd9664 100644
--- a/source/blender/makesrna/intern/rna_material.c
+++ b/source/blender/makesrna/intern/rna_material.c
@@ -367,6 +367,12 @@ static void rna_def_material_mtex(BlenderRNA *brna)
 		{MTEX_NSPACE_TANGENT, "TANGENT", 0, "Tangent", ""},
 		{0, NULL, 0, NULL, NULL}};
 
+	static EnumPropertyItem prop_bump_method_items[] = {
+		{0, "BUMP_OLD", 0, "Old Bump", ""},
+		{MTEX_NEW_BUMP, "BUMP_3_TAP", 0, "3-Tap", ""},
+		{MTEX_NEW_BUMP|MTEX_5TAP_BUMP, "BUMP_5_TAP", 0, "5-Tap", ""},
+		{0, NULL, 0, NULL, NULL}};
+
 	srna= RNA_def_struct(brna, "MaterialTextureSlot", "TextureSlot");
 	RNA_def_struct_sdna(srna, "MTex");
 	RNA_def_struct_ui_text(srna, "Material Texture Slot", "Texture slot for textures in a Material datablock");
@@ -668,9 +674,10 @@ static void rna_def_material_mtex(BlenderRNA *brna)
 	RNA_def_property_ui_text(prop, "Enabled", "Enable this material texture slot");
 	RNA_def_property_update(prop, 0, "rna_Material_update");
 
-	prop= RNA_def_property(srna, "use_old_bump", PROP_BOOLEAN, PROP_NONE);
-	RNA_def_property_boolean_negative_sdna(prop, NULL, "texflag", MTEX_NEW_BUMP);
-	RNA_def_property_ui_text(prop, "Old Bump", "Use old bump mapping (backwards compatibility option)");
+	prop= RNA_def_property(srna, "bump_method", PROP_ENUM, PROP_NONE);
+	RNA_def_property_enum_bitflag_sdna(prop, NULL, "texflag");
+	RNA_def_property_enum_items(prop, prop_bump_method_items);
+	RNA_def_property_ui_text(prop, "Bump Method", "Method to use for bump mapping");
 	RNA_def_property_update(prop, 0, "rna_Material_update");
 }