New compositor node "Sun Beams"

This allows adding a "fake" sun beam effect, simulating crepuscular rays
from light being scattered in a medium like the atmosphere or deep water.
Such effects can be created also by renderers using volumetric lighting,
but the compositor feature is a lot cheaper and is independent from 3D
rendering. This makes it ideally suited for motion graphics.

The implementation uses am optimized accumulation method for gathering
color values along a line segment. The inner buffer loop uses fixed
offset increments to avoid unnecessary multiplications and avoids
variables by using compile-time specialization (see inline comments
for further details).

1 files changed, 9 insertions, 0 deletions

diff --git a/source/blender/editors/space_node/drawnode.c b/source/blender/editors/space_node/drawnode.c
index ef23fc24194..6fa9290c732 100644
--- a/source/blender/editors/space_node/drawnode.c
+++ b/source/blender/editors/space_node/drawnode.c
@@ -2307,6 +2307,12 @@ static void node_composit_buts_cornerpin(uiLayout *UNUSED(layout), bContext *UNU
 {
 }
 
+static void node_composit_buts_sunbeams(uiLayout *layout, bContext *UNUSED(C), PointerRNA *ptr)
+{
+	uiItemR(layout, ptr, "source", UI_ITEM_R_EXPAND, "", ICON_NONE);
+	uiItemR(layout, ptr, "ray_length", UI_ITEM_R_SLIDER, NULL, ICON_NONE);
+}
+
 /* only once called */
 static void node_composit_set_butfunc(bNodeType *ntype)
 {
@@ -2531,6 +2537,9 @@ static void node_composit_set_butfunc(bNodeType *ntype)
 		case CMP_NODE_CORNERPIN:
 			ntype->draw_buttons = node_composit_buts_cornerpin;
 			break;
+		case CMP_NODE_SUNBEAMS:
+			ntype->draw_buttons = node_composit_buts_sunbeams;
+			break;
 	}
 }