Fix T47902: Particle grid not using modifier stack.

Disclaimer: this is tentative fix, seems to be working but you never know with particles.
If issue arise, we'll just revert this commit and hide 'use modifier stack' option
for grid distribution instead.

This commit also try to make choice of which dm to use during distribution more generic
(deduplication of code), again hopping not to break anything. :P

1 files changed, 17 insertions, 20 deletions

diff --git a/source/blender/blenkernel/intern/particle_distribute.c b/source/blender/blenkernel/intern/particle_distribute.c
index 2527ff5e0da..e581ac4ebb3 100644
--- a/source/blender/blenkernel/intern/particle_distribute.c
+++ b/source/blender/blenkernel/intern/particle_distribute.c
@@ -796,13 +796,23 @@ static int psys_thread_context_init_distribute(ParticleThreadContext *ctx, Parti
 	}
 	
 	psys_thread_context_init(ctx, sim);
-	
+
+	if (psys->part->use_modifier_stack)
+		dm = finaldm;
+	else
+		dm= CDDM_from_mesh((Mesh*)ob->data);
+
+	/* BMESH ONLY, for verts we don't care about tessfaces */
+	if (from != PART_FROM_VERT) {
+		DM_ensure_tessface(dm);
+	}
+
 	/* First handle special cases */
 	if (from == PART_FROM_CHILD) {
 		/* Simple children */
 		if (part->childtype != PART_CHILD_FACES) {
 			BLI_srandom(31415926 + psys->seed + psys->child_seed);
-			distribute_simple_children(scene, ob, finaldm, sim->psmd->dm_deformed, psys);
+			distribute_simple_children(scene, ob, dm, sim->psmd->dm_deformed, psys);
 			return 0;
 		}
 	}
@@ -810,10 +820,11 @@ static int psys_thread_context_init_distribute(ParticleThreadContext *ctx, Parti
 		/* Grid distribution */
 		if (part->distr==PART_DISTR_GRID && from != PART_FROM_VERT) {
 			BLI_srandom(31415926 + psys->seed);
-			dm= CDDM_from_mesh((Mesh*)ob->data);
-			DM_ensure_tessface(dm);
-			distribute_grid(dm,psys);
-			dm->release(dm);
+
+			distribute_grid(dm, psys);
+
+			if (dm != finaldm) dm->release(dm);
+
 			return 0;
 		}
 	}
@@ -822,10 +833,6 @@ static int psys_thread_context_init_distribute(ParticleThreadContext *ctx, Parti
 	if (from == PART_FROM_CHILD) {
 		distr=PART_DISTR_RAND;
 		BLI_srandom(31415926 + psys->seed + psys->child_seed);
-		dm= finaldm;
-
-		/* BMESH ONLY */
-		DM_ensure_tessface(dm);
 
 		children=1;
 
@@ -846,16 +853,6 @@ static int psys_thread_context_init_distribute(ParticleThreadContext *ctx, Parti
 		distr = part->distr;
 		BLI_srandom(31415926 + psys->seed);
 		
-		if (psys->part->use_modifier_stack)
-			dm = finaldm;
-		else
-			dm= CDDM_from_mesh((Mesh*)ob->data);
-
-		/* BMESH ONLY, for verts we don't care about tessfaces */
-		if (from != PART_FROM_VERT) {
-			DM_ensure_tessface(dm);
-		}
-
 		/* we need orco for consistent distributions */
 		if (!CustomData_has_layer(&dm->vertData, CD_ORCO))
 			DM_add_vert_layer(dm, CD_ORCO, CD_ASSIGN, BKE_mesh_orco_verts_get(ob));