Armature: Outline: Fix outline detection in critical cases.

Outline was not generated because the normal was completely orthogonal to
the view.

1 files changed, 7 insertions, 1 deletions

diff --git a/source/blender/draw/modes/shaders/armature_shape_outline_vert.glsl b/source/blender/draw/modes/shaders/armature_shape_outline_vert.glsl
index 73916163b9a..0d09114579c 100644
--- a/source/blender/draw/modes/shaders/armature_shape_outline_vert.glsl
+++ b/source/blender/draw/modes/shaders/armature_shape_outline_vert.glsl
@@ -45,7 +45,13 @@ void main()
 	 * barelly visible at the outline corners. */
 	ssNor = normalize((NormalMatrix * snor).xy);
 
-	vFacing = dot(V, normalize(NormalMatrix * nor));
+	vec3 normal = normalize(NormalMatrix * nor);
+	/* Add a small bias to avoid loosing outline
+	 * on faces orthogonal to the view.
+	 * (test case: octahedral bone without rotation in front view.) */
+	normal.z += 1e-6;
+
+	vFacing = dot(V, normal);
 
 	ssPos = proj(pPos);