Overlay Engine: Armature: Fix bones disapearing with custom bone color

This seems to only affect some drivers. Rendering to multiple targets
without all output variables defined seems to be undefined behavior.
Thanks to gaiaclary for reporting on blendercoders.

1 files changed, 3 insertions, 1 deletions

diff --git a/source/blender/draw/engines/overlay/shaders/armature_sphere_solid_frag.glsl b/source/blender/draw/engines/overlay/shaders/armature_sphere_solid_frag.glsl
index 94f339c4561..0ff0fdf0870 100644
--- a/source/blender/draw/engines/overlay/shaders/armature_sphere_solid_frag.glsl
+++ b/source/blender/draw/engines/overlay/shaders/armature_sphere_solid_frag.glsl
@@ -11,7 +11,8 @@ in vec3 viewPosition;
 layout(depth_greater) out float gl_FragDepth;
 #endif
 
-out vec4 fragColor;
+layout(location = 0) out vec4 fragColor;
+layout(location = 1) out vec4 lineOutput;
 
 #define cameraPos ViewMatrixInverse[3].xyz
 
@@ -70,6 +71,7 @@ void main()
   dither *= (1.0 / 255.0); /* Assume 8bit per color buffer. */
 
   fragColor = vec4(fragColor.rgb + dither, alpha);
+  lineOutput = vec4(0.0);
 
   t /= ray_len;
   gl_FragDepth = get_depth_from_view_z(ray_dir_view.z * t + ray_ori_view.z);