Workbench: Specular Highlighting for MatCaps

With Blender 2.80 we introduced a more flexible matcap system. One
change we did was to multiply the matcap with the base color that was
shaded. As matcaps contains diffuse and specular lighting in a single
texture this lead to rendering artifacts. Artists were complaining that
everything looked to metalic.

We now support a separate `diffuse` and `specular` pass for matcaps.

`shaded_color = diffuse_light * base_color + specular_light`

For matcaps to support this feature they need to be multilayer openexr
files with 2 renderpasses (named `diffuse` and `specular`). In the future
we can change this to first pass/second pass in stead of this naming
convention.

Reviewed By: fclem, brecht

Differential Revision: https://developer.blender.org/D5335

1 files changed, 10 insertions, 4 deletions

diff --git a/source/blender/draw/engines/workbench/workbench_deferred.c b/source/blender/draw/engines/workbench/workbench_deferred.c
index add49462de1..c1c9d8b5a96 100644
--- a/source/blender/draw/engines/workbench/workbench_deferred.c
+++ b/source/blender/draw/engines/workbench/workbench_deferred.c
@@ -694,16 +694,22 @@ static void workbench_composite_uniforms(WORKBENCH_PrivateData *wpd, DRWShadingG
   if (CAVITY_ENABLED(wpd)) {
     DRW_shgroup_uniform_texture_ref(grp, "cavityBuffer", &e_data.cavity_buffer_tx);
   }
-  if (SPECULAR_HIGHLIGHT_ENABLED(wpd) || STUDIOLIGHT_TYPE_MATCAP_ENABLED(wpd)) {
+  if (workbench_is_specular_highlight_enabled(wpd) || STUDIOLIGHT_TYPE_MATCAP_ENABLED(wpd)) {
     DRW_shgroup_uniform_vec4(grp, "viewvecs[0]", (float *)wpd->viewvecs, 3);
   }
-  if (SPECULAR_HIGHLIGHT_ENABLED(wpd) || STUDIOLIGHT_TYPE_MATCAP_ENABLED(wpd)) {
+  if (workbench_is_specular_highlight_enabled(wpd) || STUDIOLIGHT_TYPE_MATCAP_ENABLED(wpd)) {
     DRW_shgroup_uniform_vec2(grp, "invertedViewportSize", DRW_viewport_invert_size_get(), 1);
   }
   if (STUDIOLIGHT_TYPE_MATCAP_ENABLED(wpd)) {
-    BKE_studiolight_ensure_flag(wpd->studio_light, STUDIOLIGHT_EQUIRECT_RADIANCE_GPUTEXTURE);
+    BKE_studiolight_ensure_flag(wpd->studio_light,
+                                STUDIOLIGHT_MATCAP_DIFFUSE_GPUTEXTURE |
+                                    STUDIOLIGHT_MATCAP_SPECULAR_GPUTEXTURE);
     DRW_shgroup_uniform_texture(
-        grp, "matcapImage", wpd->studio_light->equirect_radiance_gputexture);
+        grp, "matcapDiffuseImage", wpd->studio_light->matcap_diffuse.gputexture);
+    if (workbench_is_specular_highlight_enabled(wpd)) {
+      DRW_shgroup_uniform_texture(
+          grp, "matcapSpecularImage", wpd->studio_light->matcap_specular.gputexture);
+    }
   }
 }