Fix for particle texture influence bug causing undefined (nan) values: When using a texture with "Particles/Strands" coordinates that in turn has a "Lifetime" influence on the particles, the texture eval

accesses the particle lifetime/dietime data before it is actually defined! This is a design flaw, but to avoid corrupted data for now just initialize the lifetime/dietime values for particles in advance
before evaluating the texture.

1 files changed, 6 insertions, 0 deletions

diff --git a/source/blender/blenkernel/intern/particle_system.c b/source/blender/blenkernel/intern/particle_system.c
index 526d54a97fa..ac32f96d59c 100644
--- a/source/blender/blenkernel/intern/particle_system.c
+++ b/source/blender/blenkernel/intern/particle_system.c
@@ -2006,6 +2006,12 @@ void reset_particle(ParticleSimulationData *sim, ParticleData *pa, float dtime,
 		pa->lifetime = 100.0f;
 	}
 	else {
+		/* initialize the lifetime, in case the texture coordinates
+		 * are from Particles/Strands, which would cause undefined values
+		 */
+		pa->lifetime = part->lifetime * (1.0f - part->randlife * PSYS_FRAND(p + 21));
+		pa->dietime = pa->time + pa->lifetime;
+
 		/* get possible textural influence */
 		psys_get_texture(sim, pa, &ptex, PAMAP_LIFE, cfra);