Oops, particle collisions didn't take simulation subframes into account at all.

* This caused nearly all particles to leak through the collision surface if simulation subframes were used and the collision object was moving.
* In addition to fixing this I also did some more cleanup of the collision code and refined some of the comments.

1 files changed, 9 insertions, 3 deletions

diff --git a/source/blender/blenkernel/intern/boids.c b/source/blender/blenkernel/intern/boids.c
index 5c2c0721972..1bde0639055 100644
--- a/source/blender/blenkernel/intern/boids.c
+++ b/source/blender/blenkernel/intern/boids.c
@@ -205,7 +205,9 @@ static int rule_avoid_collision(BoidRule *rule, BoidBrainData *bbd, BoidValues *
 		add_v3_v3v3(col.co2, pa->prev_state.co, pa->prev_state.vel);
 		sub_v3_v3v3(ray_dir, col.co2, col.co1);
 		mul_v3_fl(ray_dir, acbr->look_ahead);
-		col.t = 0.0f;
+		col.f = 0.0f;
+		col.cfra = fmod(bbd->cfra-bbd->dfra, 1.0f);
+		col.dfra = bbd->dfra;
 		hit.index = -1;
 		hit.dist = col.ray_len = len_v3(ray_dir);
 
@@ -772,7 +774,9 @@ static Object *boid_find_ground(BoidBrainData *bbd, ParticleData *pa, float *gro
 		sub_v3_v3v3(col.co2, pa->state.co, zvec);
 		sub_v3_v3(col.co2, zvec);
 		sub_v3_v3v3(ray_dir, col.co2, col.co1);
-		col.t = 0.0f;
+		col.f = 0.0f;
+		col.cfra = fmod(bbd->cfra-bbd->dfra, 1.0f);
+		col.dfra = bbd->dfra;
 		hit.index = -1;
 		hit.dist = col.ray_len = len_v3(ray_dir);
 
@@ -796,7 +800,9 @@ static Object *boid_find_ground(BoidBrainData *bbd, ParticleData *pa, float *gro
 		sub_v3_v3v3(col.co2, pa->state.co, zvec);
 		sub_v3_v3(col.co2, zvec);
 		sub_v3_v3v3(ray_dir, col.co2, col.co1);
-		col.t = 0.0f;
+		col.f = 0.0f;
+		col.cfra = fmod(bbd->cfra-bbd->dfra, 1.0f);
+		col.dfra = bbd->dfra;
 		hit.index = -1;
 		hit.dist = col.ray_len = len_v3(ray_dir);