* changes/additions to volume lighting

Volumes can now receive shadows from external objects, either raytraced shadows or shadow maps.

To use external shadows, enable 'external shadows' in volume material 'lighting' panel. This an extra toggle since it causes a performance hit, but this can probably be revisited/optimised when the new raytrace accelerator is integrated. For shadow maps at least, it's still very quick.

Renamed 'scattering mode' to 'lighting mode' (a bit simpler to understand), and the options inside. Now there's:

- Shadeless
  takes light contribution, but without shadowing or self-shading (fast)
  good for fog-like volumes, such as mist, or underwater effects
  
- Shadowed (new)
  takes light contribution with shadows, but no self-shading. (medium)
  good for mist etc. with directional light sources
  eg. http://vimeo.com/6901636
  
- Shaded
  takes light contribution with internal/external shadows, and self shading (slower)
  good for thicker/textured volumes like smoke
  
- Multiple scattering etc (still doesn't work properly, on the todo).

1 files changed, 6 insertions, 6 deletions

diff --git a/source/blender/makesdna/DNA_material_types.h b/source/blender/makesdna/DNA_material_types.h
index a925b60ac33..36de890e6dc 100644
--- a/source/blender/makesdna/DNA_material_types.h
+++ b/source/blender/makesdna/DNA_material_types.h
@@ -374,15 +374,15 @@ typedef struct Material {
 #define MA_VOL_STEP_ADAPTIVE	2
 
 /* vol_shadeflag */
-#define MA_VOL_SHADED		1
-#define MA_VOL_RECVSHADOW	4
+#define MA_VOL_RECV_EXT_SHADOW	1
 #define MA_VOL_PRECACHESHADING	8
 
 /* vol_shading_type */
-#define MA_VOL_SHADE_NONE					0
-#define MA_VOL_SHADE_SINGLE					1
-#define MA_VOL_SHADE_MULTIPLE				2
-#define MA_VOL_SHADE_SINGLEPLUSMULTIPLE		3
+#define MA_VOL_SHADE_SHADELESS					0
+#define MA_VOL_SHADE_SHADOWED					2
+#define MA_VOL_SHADE_SHADED						1
+#define MA_VOL_SHADE_MULTIPLE					3
+#define MA_VOL_SHADE_SHADEDPLUSMULTIPLE			4
 
 #endif