Optional clumping noise feature for simulating twisted hair strands.

This adds another level of clumping on child hairs. When enabled, child
hairs chose a secondary clumping target using a Voronoi pattern. This
adds visual detail on a smaller scale, which is useful particularly when
the number of parents is relatively small.

Natural fibres behave in a similar way when they become sticky and
intertwined. Hairs close to each other form a first twisted strand, then
combine into larger strands. Similar features can be found in ropes:
http://en.wikipedia.org/wiki/Hair_twists
http://en.wikipedia.org/wiki/Rope

Conflicts:
	source/blender/blenloader/intern/versioning_270.c

1 files changed, 8 insertions, 1 deletions

diff --git a/source/blender/makesdna/DNA_particle_types.h b/source/blender/makesdna/DNA_particle_types.h
index b5ba7fa1649..8bae57a7cbd 100644
--- a/source/blender/makesdna/DNA_particle_types.h
+++ b/source/blender/makesdna/DNA_particle_types.h
@@ -208,6 +208,8 @@ typedef struct ParticleSettings {
 	/* length */
 	float randlength;
 	/* children */
+	int child_flag;
+	int pad3;
 	int child_nbr, ren_child_nbr;
 	float parents, childsize, childrandsize;
 	float childrad, childflat;
@@ -235,10 +237,10 @@ typedef struct ParticleSettings {
 	int keyed_loops;
 	struct CurveMapping *clumpcurve;
 	struct CurveMapping *roughcurve;
+	float clump_noise_size;
 
 	/* hair dynamics */
 	float bending_random;
-	int pad3;
 
 	struct MTex *mtex[18];		/* MAX_MTEX */
 
@@ -421,6 +423,11 @@ typedef enum eParticleDrawFlag {
 #define PART_KINK_WAVE		3
 #define PART_KINK_BRAID		4
 
+/* part->kink_flag */
+typedef enum eParticleChildFlag {
+	PART_CHILD_USE_CLUMP_NOISE  = 1,
+} eParticleChildFlag;
+
 /* part->draw_col */
 #define PART_DRAW_COL_NONE		0
 #define PART_DRAW_COL_MAT		1