Merge pull request #38346 from jitspoe/master.fix_uninitialized_particle_param

Fix custom w component being uninitialized on CPU particles.

scene/3d/cpu_particles_3d.cpp

@@ -69,6 +69,7 @@ void CPUParticles3D::set_amount(int p_amount) {
 
 		for (int i = 0; i < p_amount; i++) {
 			w[i].active = false;
+			w[i].custom[3] = 0.0; // Make sure w component isn't garbage data
 		}
 	}