EEVEE: Lookdev: Add support for partially blurred background

This is using the GGX probe as background. This has the drawback of
having the resolution choosed in the indirect lighting setting.
The blurring is not really high-quality.

The pros is that it has a simple implementation and is fast to evaluate.

This patch also fades the background alpha to make overlay engine draw the
default background color in the correct color space. Removing one colorspace
hack.

Reviewed By: jbakker

Differential Revision: https://developer.blender.org/D6895

1 files changed, 11 insertions, 2 deletions

diff --git a/source/blender/makesrna/intern/rna_space.c b/source/blender/makesrna/intern/rna_space.c
index 975a3bdaf2e..3d5d5091bf1 100644
--- a/source/blender/makesrna/intern/rna_space.c
+++ b/source/blender/makesrna/intern/rna_space.c
@@ -3239,9 +3239,18 @@ static void rna_def_space_view3d_shading(BlenderRNA *brna)
 
   prop = RNA_def_property(srna, "studiolight_background_alpha", PROP_FLOAT, PROP_FACTOR);
   RNA_def_property_float_sdna(prop, NULL, "studiolight_background");
-  RNA_def_property_ui_text(prop, "Background", "Show the studiolight in the background");
+  RNA_def_property_ui_text(prop, "World Opacity", "Show the studiolight in the background");
   RNA_def_property_range(prop, 0.0f, 1.0f);
-  RNA_def_property_ui_range(prop, 0.00f, 1.0f, 1, 3);
+  RNA_def_property_ui_range(prop, 0.0f, 1.0f, 1, 3);
+  RNA_def_property_clear_flag(prop, PROP_ANIMATABLE);
+  RNA_def_property_update(prop, NC_SPACE | ND_SPACE_VIEW3D, NULL);
+
+  prop = RNA_def_property(srna, "studiolight_background_blur", PROP_FLOAT, PROP_FACTOR);
+  RNA_def_property_float_sdna(prop, NULL, "studiolight_blur");
+  RNA_def_property_ui_text(prop, "Blur", "Blur the studiolight in the background");
+  RNA_def_property_float_default(prop, 0.5f);
+  RNA_def_property_range(prop, 0.0f, 1.0f);
+  RNA_def_property_ui_range(prop, 0.0f, 1.0f, 1, 2);
   RNA_def_property_clear_flag(prop, PROP_ANIMATABLE);
   RNA_def_property_update(prop, NC_SPACE | ND_SPACE_VIEW3D, NULL);