Bake from multires mesh

=======================

Added option to baked named "Bake From Multires" which is avaliable for
normals baking and displacement baking.

If this option is enabled, then no additional hi-res meshes and render
structures would be created . This saves plenty of memory and meshes
with millions of faces could be successfully baked in few minutes.

Baking happens from highest level against viewport subdivision level,
so workflow is following:
  - Set viewport level to level at which texture would be applied
    during final rendering.
  - Choose Displacement/Normals baking.
  - Enable "Bake From Multires" option.
  - You're ready to bake.

Displacement baker had aditional option named "Low Resolution Mesh".
This option is used to set if you want texture for realtime (games)
usage.

Internally it does the following:
  - If it's disabled, displacement is calculated from subdivided
    viewport level, so texture looks "smooth" (it's how default
    baked works).
  - If it's enabled, dispalcement is calculated against unsubdivided
    viewport levels. This leads to "scales". This isn;t useful for
    offline renders much, but very useful for creating game textures.

Special thanks to Morten Mikkelsen (aka sparky) for all mathematics
and other work he've done fr this patch!

1 files changed, 2 insertions, 1 deletions

diff --git a/source/blender/makesdna/DNA_scene_types.h b/source/blender/makesdna/DNA_scene_types.h
index 657bfb1c884..70e90cfc713 100644
--- a/source/blender/makesdna/DNA_scene_types.h
+++ b/source/blender/makesdna/DNA_scene_types.h
@@ -1009,13 +1009,14 @@ typedef struct Scene {
 #define R_JPEG2K_CINE_PRESET	256
 #define R_JPEG2K_CINE_48FPS		512
 
-
 /* bake_mode: same as RE_BAKE_xxx defines */
 /* bake_flag: */
 #define R_BAKE_CLEAR		1
 #define R_BAKE_OSA			2
 #define R_BAKE_TO_ACTIVE	4
 #define R_BAKE_NORMALIZE	8
+#define R_BAKE_MULTIRES		16
+#define R_BAKE_LORES_MESH	32
 
 /* bake_normal_space */
 #define R_BAKE_SPACE_CAMERA	 0