Deep Shadow Buffer

Since the deep shadow buffer summer of code project is not actively under
development anymore, I decided to build my own DSM implementation from
scratch, based on reusing as much existing shadow buffer code as possible.
It's not very advanced, but implements the basic algorithm. Just enough so
we can do shading tests with it, optimizations and other improvements can
be done later.

Supported:
* Classical shadow buffer options: filter, soft, bias, ..
* Multiple sample buffers, merged into one.
* Halfway trick to support lower bias.
* Compression with user defined threshold.
* Non-textured alpha transparency, using Casting Alpha value.
* Strand render.

Not Supported:
* Tiling disk cache, so can use a lot of memory.
* Per part rendering for lower memory usage during creation.
* Colored shadow.
* Textured color/alpha shadow.
* Mipmaps for faster filtering.
* Volume shadows.

Usage Hints:
* Use sample buffers + smaller size rather than large size.
* For example 512 size x 9 sample buffers instead of 2048 x 1.
* Compression threshold 0.05 works, but is on the conservative side.

1 files changed, 7 insertions, 0 deletions

diff --git a/source/blender/makesrna/intern/rna_lamp.c b/source/blender/makesrna/intern/rna_lamp.c
index 4ad1f942b33..a518bd28d24 100644
--- a/source/blender/makesrna/intern/rna_lamp.c
+++ b/source/blender/makesrna/intern/rna_lamp.c
@@ -570,6 +570,7 @@ static void rna_def_spot_lamp(BlenderRNA *brna)
 		{LA_SHADBUF_REGULAR	, "REGULAR", 0, "Classical", "Classic shadow buffer."},
 		{LA_SHADBUF_HALFWAY, "HALFWAY", 0, "Classic-Halfway", "Regular buffer, averaging the closest and 2nd closest Z value to reducing bias artifaces."},
 		{LA_SHADBUF_IRREGULAR, "IRREGULAR", 0, "Irregular", "Irregular buffer produces sharp shadow always, but it doesn't show up for raytracing."},
+		{LA_SHADBUF_DEEP, "DEEP", 0, "Deep", "Deep shadow buffer supports transparency and better filtering, at the cost of more memory usage and processing time."},
 		{0, NULL, 0, NULL, NULL}};
 
 	static EnumPropertyItem prop_shadbuffiltertype_items[] = {
@@ -690,6 +691,12 @@ static void rna_def_spot_lamp(BlenderRNA *brna)
 	RNA_def_property_boolean_sdna(prop, NULL, "bufflag", LA_SHADBUF_AUTO_END);
 	RNA_def_property_ui_text(prop, "Autoclip End", "Automatic calculation of clipping-end, based on visible vertices.");
 	RNA_def_property_update(prop, 0, "rna_Lamp_draw_update");
+
+	prop= RNA_def_property(srna, "compression_threshold", PROP_FLOAT, PROP_NONE);
+	RNA_def_property_float_sdna(prop, NULL, "compressthresh");
+	RNA_def_property_range(prop, 0.0f, 1.0f);
+	RNA_def_property_ui_text(prop, "Compress", "Deep shadow map compression threshold.");
+	RNA_def_property_update(prop, 0, "rna_Lamp_update");
 }
 
 static void rna_def_sun_lamp(BlenderRNA *brna)