A bunch of fun stuff now possible because of new pointcache code:

* Baked normal particles can now use the "Path" visualization.
* Path "max length" & "abs length" are now history:
	- New option to set path start & end times + random variation to length.
	- Much more flexible (and calculated better) than previous options.
	- This works with parents, children, hair & normal particles unlike old length option.
	- Only known issue for now is that children from faces don't get calculated correctly when using path start time.
* New option "trails" for "halo", "line" and "billboard" visualizations:
	- Draws user controllable number of particle instances along particles path backwards from current position.
	- Works with children too for cool/weird visualizations that weren't possible before.
* Normal particle children's velocities are now approximated better when needed so that "line" visualization trails will look nice.
* New particle instance modifier options:
	- "path"-option works better and has controllable (max)position along path (with random variation possible).
	- "keep shape"-option for hair, keyed, or baked particles allows to place the instances to a single point (with random variation possible) along particle path.
	- "axis" option to make rotation handling better (still not perfect, but will have to do for now).

Some fixes & cleanup done along the way:
* Random path length didn't work for non-child particles.
* Cached & unborn particles weren't reset to emit locations.
* Particle numbers weren't drawn in the correct place.
* Setting proper render & draw visualizations was lost somewhere when initializing new particle settings.
* Changing child mode wasn't working correctly.
* Some cleanup & modularization of particle child effector code and particle drawing & rendering code.
* Object & group visualizations didn't work.
* Child simplification didn't work.

1 files changed, 3 insertions, 1 deletions

diff --git a/source/blender/makesdna/DNA_modifier_types.h b/source/blender/makesdna/DNA_modifier_types.h
index 76f6b980aa2..1fa17760e8d 100644
--- a/source/blender/makesdna/DNA_modifier_types.h
+++ b/source/blender/makesdna/DNA_modifier_types.h
@@ -503,12 +503,14 @@ typedef enum {
 	eParticleInstanceFlag_Unborn =		(1<<3),
 	eParticleInstanceFlag_Alive =		(1<<4),
 	eParticleInstanceFlag_Dead =		(1<<5),
+	eParticleInstanceFlag_KeepShape =	(1<<6),
 } ParticleInstanceModifierFlag;
 
 typedef struct ParticleInstanceModifierData {
 	ModifierData modifier;
 	struct Object *ob;
-	short psys, flag, rt[2];
+	short psys, flag, axis, rt;
+	float position, random_position;
 } ParticleInstanceModifierData;
 
 typedef enum {