Derivative map baker

Added support for derivative map baking, which
is accessable as a dedicated baker type. Works
pretty much the same as displacement map baker,
but gives you derivative map.

In fact, inernally this baker is just a filter
which applies on the result of displacement map.

Both regular and multires baking are supported.

Patch by Morten Mikkelsen and self.

3 files changed, 17 insertions, 8 deletions

diff --git a/source/blender/render/extern/include/RE_multires_bake.h b/source/blender/render/extern/include/RE_multires_bake.h
index 04cfe55e3a3..c1c5fc4a04d 100644
--- a/source/blender/render/extern/include/RE_multires_bake.h
+++ b/source/blender/render/extern/include/RE_multires_bake.h
@@ -37,21 +37,26 @@ struct MultiresBakeRender;
 
 typedef struct MultiresBakeRender {
 	DerivedMesh *lores_dm, *hires_dm;
-	int simple, lvl, tot_lvl, bake_filter;
-	short mode, use_lores_mesh;
+	bool simple;
+	int bake_filter;      /* Bake-filter, aka margin */
+	int lvl, tot_lvl;
+	short mode;
+	bool use_lores_mesh;  /* Use low-resolution mesh when baking displacement maps */
 
-	int number_of_rays;
-	float bias;
+	int number_of_rays;   /* Number of rays to be cast when doing AO baking */
+	float bias;           /* Bias between object and start ray point when doing AO baking */
 
 	int tot_obj, tot_image;
 	ListBase image;
 
 	int baked_objects, baked_faces;
 
-	int raytrace_structure;
-	int octree_resolution;
-	int threads;
-	
+	int raytrace_structure;    /* Optimization structure to be used for AO baking */
+	int octree_resolution;     /* Reslution of octotree when using octotree optimization structure */
+	int threads;               /* Number of threads to be used for baking */
+
+	float user_scale;          /* User scale used to scale displacement when baking derivative map. */
+
 	short *stop;
 	short *do_update;
 	float *progress;
diff --git a/source/blender/render/extern/include/RE_pipeline.h b/source/blender/render/extern/include/RE_pipeline.h
index 73a89ad884f..35d971ab976 100644
--- a/source/blender/render/extern/include/RE_pipeline.h
+++ b/source/blender/render/extern/include/RE_pipeline.h
@@ -281,6 +281,7 @@ int RE_seq_render_active(struct Scene *scene, struct RenderData *rd);
 #define RE_BAKE_MIRROR_INTENSITY	10
 #define RE_BAKE_ALPHA				11
 #define RE_BAKE_EMIT				12
+#define RE_BAKE_DERIVATIVE		13
 
 void RE_Database_Baking(struct Render *re, struct Main *bmain, struct Scene *scene, unsigned int lay, const int type, struct Object *actob);
 
diff --git a/source/blender/render/extern/include/RE_shader_ext.h b/source/blender/render/extern/include/RE_shader_ext.h
index 19ddfb7a13d..baec1a74721 100644
--- a/source/blender/render/extern/include/RE_shader_ext.h
+++ b/source/blender/render/extern/include/RE_shader_ext.h
@@ -213,6 +213,9 @@ int RE_bake_shade_all_selected(struct Render *re, int type, struct Object *actob
 struct Image *RE_bake_shade_get_image(void);
 void RE_bake_ibuf_filter(struct ImBuf *ibuf, char *mask, const int filter);
 void RE_bake_ibuf_normalize_displacement(struct ImBuf *ibuf, float *displacement, char *mask, float displacement_min, float displacement_max);
+float RE_bake_make_derivative(struct ImBuf *ibuf, float *heights_buffer, const char *mask,
+                              const float height_min, const float height_max,
+                              const float fmult);
 
 #define BAKE_RESULT_OK			0
 #define BAKE_RESULT_NO_OBJECTS		1