Recalculate particle pathcache stuff for all particles instead of

trying to be smart.

This breaks child interpolation otherwise because sometimes parent
paths are not calculated and give bad clumping results.

source/blender/blenkernel/intern/particle.c

@@ -3000,7 +3000,7 @@ void psys_cache_paths(ParticleSimulationData *sim, float cfra)
 	}
 
 	/*---first main loop: create all actual particles' paths---*/
-	LOOP_SHOWN_PARTICLES {
+	LOOP_PARTICLES {
 		if (!psys->totchild) {
 			psys_get_texture(sim, pa, &ptex, PAMAP_LENGTH, 0.f);
 			pa_length = ptex.length * (1.0f - part->randlength * psys_frand(psys, psys->seed + p));