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, 23 insertions, 20 deletions

diff --git a/intern/cycles/blender/blender_object.cpp b/intern/cycles/blender/blender_object.cpp
index cea3b0256bd..b70491a7b82 100644
--- a/intern/cycles/blender/blender_object.cpp
+++ b/intern/cycles/blender/blender_object.cpp
@@ -192,7 +192,7 @@ void BlenderSync::sync_background_light()
 
 /* Object */
 
-void BlenderSync::sync_object(BL::Object b_parent, int b_index, BL::Object b_ob, Transform& tfm, uint layer_flag, int motion)
+void BlenderSync::sync_object(BL::Object b_parent, int b_index, BL::Object b_ob, Transform& tfm, uint layer_flag, int motion, int particle_id)
 {
 	/* light is handled separately */
 	if(object_is_light(b_ob)) {
@@ -270,6 +270,12 @@ void BlenderSync::sync_object(BL::Object b_parent, int b_index, BL::Object b_ob,
 			object->visibility &= ~PATH_RAY_CAMERA;
 		}
 
+		object->particle_id = particle_id;
+
+		/* particle sync */
+		if (object_use_particles(b_ob))
+			sync_particles(object, b_ob);
+	
 		object->tag_update(scene);
 	}
 }
@@ -292,54 +298,51 @@ void BlenderSync::sync_objects(BL::SpaceView3D b_v3d, int motion)
 	/* object loop */
 	BL::Scene::objects_iterator b_ob;
 	BL::Scene b_sce = b_scene;
+	int particle_offset = 0;
 
 	for(; b_sce; b_sce = b_sce.background_set()) {
 		for(b_sce.objects.begin(b_ob); b_ob != b_sce.objects.end(); ++b_ob) {
 			bool hide = (render_layer.use_viewport_visibility)? b_ob->hide(): b_ob->hide_render();
 			uint ob_layer = get_layer(b_ob->layers());
+			hide = hide || !(ob_layer & scene_layer);
+
+			if(!hide) {
+
+				int num_particles = object_count_particles(*b_ob);
 
-			if(!hide && (ob_layer & scene_layer)) {
 				if(b_ob->is_duplicator()) {
+					hide = true;	/* duplicators hidden by default */
+
 					/* dupli objects */
 					object_create_duplilist(*b_ob, b_scene);
 
 					BL::Object::dupli_list_iterator b_dup;
-					int b_index = 0;
-
 					for(b_ob->dupli_list.begin(b_dup); b_dup != b_ob->dupli_list.end(); ++b_dup) {
 						Transform tfm = get_transform(b_dup->matrix());
 						BL::Object b_dup_ob = b_dup->object();
 						bool dup_hide = (b_v3d)? b_dup_ob.hide(): b_dup_ob.hide_render();
 
-						if(!(b_dup->hide() || dup_hide))
-							sync_object(*b_ob, b_index, b_dup_ob, tfm, ob_layer, motion);
-
-						b_index++;
+						if(!(b_dup->hide() || dup_hide)) {
+							sync_object(*b_ob, b_dup->index(), b_dup_ob, tfm, ob_layer, motion, b_dup->particle_index() + particle_offset);
+						}
 					}
 
 					object_free_duplilist(*b_ob);
-
-					hide = true;
 				}
 
 				/* check if we should render or hide particle emitter */
 				BL::Object::particle_systems_iterator b_psys;
-				bool render_emitter = false;
-
-				for(b_ob->particle_systems.begin(b_psys); b_psys != b_ob->particle_systems.end(); ++b_psys) {
-					if(b_psys->settings().use_render_emitter()) {
+				for(b_ob->particle_systems.begin(b_psys); b_psys != b_ob->particle_systems.end(); ++b_psys)
+					if(b_psys->settings().use_render_emitter())
 						hide = false;
-						render_emitter = true;
-					}
-					else if(!render_emitter)
-						hide = true;
-				}
 
 				if(!hide) {
 					/* object itself */
 					Transform tfm = get_transform(b_ob->matrix_world());
-					sync_object(*b_ob, 0, *b_ob, tfm, ob_layer, motion);
+					sync_object(*b_ob, 0, *b_ob, tfm, ob_layer, motion, 0);
 				}
+
+				particle_offset += num_particles;
 			}
 		}
 	}