Workbench: SeeThrough draw option

Option to see through all meshes (transparency)

Works for OB_SOLID and OB_TEXTURED. Does not work for
V3D_SHADING_SHADOW.

TODO: Fresnel effect

1 files changed, 54 insertions, 0 deletions

diff --git a/source/blender/draw/engines/workbench/shaders/workbench_forward_transparent_accum_frag.glsl b/source/blender/draw/engines/workbench/shaders/workbench_forward_transparent_accum_frag.glsl
new file mode 100644
index 00000000000..7eb5336e303
--- /dev/null
+++ b/source/blender/draw/engines/workbench/shaders/workbench_forward_transparent_accum_frag.glsl
@@ -0,0 +1,54 @@
+uniform vec4 color = vec4(0.0, 0.0, 1.0, 1.0);
+#ifdef OB_TEXTURE
+uniform sampler2D image;
+#endif
+uniform mat3 normalWorldMatrix;
+
+#ifdef NORMAL_VIEWPORT_PASS_ENABLED
+in vec3 normal_viewport;
+#endif /* NORMAL_VIEWPORT_PASS_ENABLED */
+#ifdef OB_TEXTURE
+in vec2 uv_interp;
+#endif
+
+layout(std140) uniform world_block {
+	WorldData world_data;
+};
+
+layout(location=0) out vec4 transparentAccum;
+
+vec4 calculate_transparent_accum(vec4 premultiplied) {
+	float a = min(1.0, premultiplied.a) * 8.0 + 0.01;
+	float b = -gl_FragCoord.z * 0.95 + 1.0;
+	float w = clamp(a * a * a * 1e8 * b * b * b, 1e-2, 3e2);
+	return vec4(premultiplied.rgb, premultiplied.a);
+}
+void main()
+{
+	vec4 diffuse_color;
+#ifdef OB_SOLID
+	diffuse_color = color;
+#endif /* OB_SOLID */
+#ifdef OB_TEXTURE
+	diffuse_color = texture(image, uv_interp);
+#endif /* OB_TEXTURE */
+
+#ifdef V3D_LIGHTING_STUDIO
+#ifdef STUDIOLIGHT_ORIENTATION_CAMERA
+	vec3 diffuse_light = get_camera_diffuse_light(world_data, normal_viewport);
+#endif
+#ifdef STUDIOLIGHT_ORIENTATION_WORLD
+	vec3 normal_world = normalWorldMatrix * normal_viewport;
+	vec3 diffuse_light = get_world_diffuse_light(world_data, normal_world);
+#endif
+	vec3 shaded_color = diffuse_light * diffuse_color.rgb;
+
+#else /* V3D_LIGHTING_STUDIO */
+	vec3 shaded_color = diffuse_color.rgb;
+#endif /* V3D_LIGHTING_STUDIO */
+
+	float alpha = world_data.see_through_transparency;
+	vec4 premultiplied = vec4(shaded_color.rgb * alpha, alpha);
+	transparentAccum = calculate_transparent_accum(premultiplied);
+}
+