Particle Info node for Cycles. This can be used to access particle information in material shaders for dupli objects. For now only the particle Age and individual Lifetime (in frames) are supported, more attributes can be added when needed.

The particle data is stored in a separate texture if any of the dupli objects uses particle info nodes in shaders. To map dupli objects onto particles the store an additional particle_index value, which is different from the simple dupli object index (only visible particles, also works for particle dupli groups mode).

Some simple use cases on the code.blender.org blog:
http://code.blender.org/index.php/2012/05/particle-info-node/

1 files changed, 22 insertions, 0 deletions

diff --git a/intern/cycles/kernel/svm/svm_geometry.h b/intern/cycles/kernel/svm/svm_geometry.h
index dab19983946..88127b56474 100644
--- a/intern/cycles/kernel/svm/svm_geometry.h
+++ b/intern/cycles/kernel/svm/svm_geometry.h
@@ -94,5 +94,27 @@ __device void svm_node_object_info(KernelGlobals *kg, ShaderData *sd, float *sta
 	stack_store_float(stack, out_offset, data);
 }
 
+/* Particle Info */
+
+__device void svm_node_particle_info(KernelGlobals *kg, ShaderData *sd, float *stack, uint type, uint out_offset)
+{
+	float data;
+
+	switch(type) {
+		case NODE_INFO_PAR_AGE: {
+			uint particle_id = object_particle_id(kg, sd->object);
+			data = particle_age(kg, particle_id);
+			stack_store_float(stack, out_offset, data);
+			break;
+		}
+		case NODE_INFO_PAR_LIFETIME: {
+			uint particle_id = object_particle_id(kg, sd->object);
+			data = particle_lifetime(kg, particle_id);
+			stack_store_float(stack, out_offset, data);
+			break;
+		}
+	}
+}
+
 CCL_NAMESPACE_END