[Bf-blender-cvs] [6f67dc10800] fluid-mantaflow: fix for required shift when domains moves

[Sebastián Barschkis]

Commit: 6f67dc10800f58c74ff4c00bf61d204691303537
Author: Sebastián Barschkis
Date:   Sat Jun 10 10:57:54 2017 +0200
Branches: fluid-mantaflow
https://developer.blender.org/rB6f67dc10800f58c74ff4c00bf61d204691303537

fix for required shift when domains moves

when domain moves away from position it was originally simulated it, a shift needs to be added to the particle coords. the was opposite to what is needed.

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

M	source/blender/blenkernel/intern/particle_system.c

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

diff --git a/source/blender/blenkernel/intern/particle_system.c b/source/blender/blenkernel/intern/particle_system.c
index 385e1341d1d..0807c4f7215 100644
--- a/source/blender/blenkernel/intern/particle_system.c
+++ b/source/blender/blenkernel/intern/particle_system.c
@@ -3820,8 +3820,6 @@ static void particles_manta_step(ParticleSimulationData *sim, int UNUSED(cfra),
 
 					// scale up
 					mul_v3_fl(pa->state.co, sds->scale);
-					// scale up to match actual domain size. also take care of domain translations globally
-					mul_m4_v3(sds->obmat, pa->state.co);
 
 					/* calculate required shift to match domain's global position
 					 *  it was originally simulated at (if object moves without step) */
@@ -3829,10 +3827,13 @@ static void particles_manta_step(ParticleSimulationData *sim, int UNUSED(cfra),
 					mul_m4_v3(ob->obmat, ob_loc);
 					mul_m4_v3(sds->obmat, ob_cache_loc);
 					VECSUB(sds->obj_shift_f, ob_cache_loc, ob_loc);
-					/* convert shift to local space and apply to vertices */
+					/* convert shift to local space and apply to particles */
 					mul_mat3_m4_v3(ob->imat, sds->obj_shift_f);
 					/* apply */
-					add_v3_v3(pa->state.co, sds->obj_shift_f);
+					sub_v3_v3(pa->state.co, sds->obj_shift_f);
+
+					// scale up to match actual domain size. also take care of domain translations globally
+					mul_m4_v3(sds->obmat, pa->state.co);
 
 //					printf("pa->state.co[0]: %f, pa->state.co[1]: %f, pa->state.co[2]: %f\n", pa->state.co[0], pa->state.co[1], pa->state.co[2]);