diff --git a/scene_viz.py b/scene_viz.py
index 7db7236..4f4c988 100644
--- a/scene_viz.py
+++ b/scene_viz.py
@@ -46,7 +46,7 @@ def __init__(self, objects: List[ObjDescriptor], prop: dict):
         self.inv_focal[None] = 1. / self.focal[None]
 
         self.num_objects = len(objects)
-        max_tri_num = max([obj.tri_num for obj in objects])
+        self.num_prims = sum([obj.tri_num for obj in objects])
 
         self.cam_orient = ti.Vector.field(3, float, ())
         self.cam_t      = ti.Vector.field(3, float, ())
@@ -60,15 +60,16 @@ def __init__(self, objects: List[ObjDescriptor], prop: dict):
         
         self.aabbs      = ti.Vector.field(3, float, (self.num_objects, 2))
         self.normals    = ti.Vector.field(3, float)
-        self.meshes     = ti.Vector.field(3, float)                    # leveraging SSDS, shape (N, mesh_num, 3) - vector3d
+        self.prims      = ti.Vector.field(3, float)                             # leveraging SSDS, shape (N, mesh_num, 3) - vector3d
         self.precom_vec = ti.Vector.field(3, float)
         self.pixels     = ti.Vector.field(3, float, (1024, 1024))      # maximum size: 1024
 
-        self.bitmasked_nodes = ti.root.dense(ti.i, self.num_objects).bitmasked(ti.j, max_tri_num)
-        self.bitmasked_nodes.place(self.normals)
-        self.bitmasked_nodes.bitmasked(ti.k, 3).place(self.meshes)      # for simple shapes, this would be efficient
-        self.bitmasked_nodes.dense(ti.k, 3).place(self.precom_vec)
-        self.mesh_cnt   = ti.field(int, self.num_objects)
+        self.dense_nodes = ti.root.dense(ti.i, self.num_prims)
+        self.dense_nodes.place(self.normals)
+        self.dense_nodes.dense(ti.j, 3).place(self.prims, self.precom_vec)      # for simple shapes, this would be efficient
+
+        # pos0: start_idx, pos1: number of primitives, pos2: obj_id (being triangle / sphere? Others to be added, like cylinder, etc.)
+        self.obj_info  = ti.field(int, (self.num_objects, 3))
         self.initialze(objects)
 
     def set_width(self, val: int):
@@ -91,19 +92,26 @@ def local_to_global(self):
         return forward, lateral, elevate
 
     def initialze(self, objects: List[ObjDescriptor]):
+        acc_prim_num = 0
         for i, obj in enumerate(objects):
             for j, (mesh, normal) in enumerate(zip(obj.meshes, obj.normals)):
-                self.normals[i, j] = vec3(normal) 
-                for k, vec in enumerate(mesh):
-                    self.meshes[i, j, k]  = vec3(vec)
+                cur_id = acc_prim_num + j
+                self.prims[cur_id, 0] = vec3(mesh[0])
+                self.prims[cur_id, 1] = vec3(mesh[1])
                 if mesh.shape[0] > 2:       # not a sphere
-                    self.precom_vec[i, j, 0] = self.meshes[i, j, 1] - self.meshes[i, j, 0]                    
-                    self.precom_vec[i, j, 1] = self.meshes[i, j, 2] - self.meshes[i, j, 0]             
-                    self.precom_vec[i, j, 2] = self.meshes[i, j, 0]
+                    self.prims[cur_id, 2] = vec3(mesh[2])
+                    self.precom_vec[cur_id, 0] = self.prims[cur_id, 1] - self.prims[cur_id, 0]                    
+                    self.precom_vec[cur_id, 1] = self.prims[cur_id, 2] - self.prims[cur_id, 0] 
+                    self.precom_vec[cur_id, 2] = self.prims[cur_id, 0]
                 else:
-                    self.precom_vec[i, j, 0] = self.meshes[i, j, 0]
-                    self.precom_vec[i, j, 1] = self.meshes[i, j, 1]
-            self.mesh_cnt[i]    = obj.tri_num
+                    self.precom_vec[cur_id, 0] = self.prims[cur_id, 0]
+                    self.precom_vec[cur_id, 1] = self.prims[cur_id, 1]           
+                self.normals[cur_id] = vec3(normal) 
+            self.obj_info[i, 0] = acc_prim_num
+            self.obj_info[i, 1] = obj.tri_num
+            self.obj_info[i, 2] = obj.type
+            acc_prim_num        += obj.tri_num
+
             self.aabbs[i, 0]    = vec3(obj.aabb[0])        # unrolled
             self.aabbs[i, 1]    = vec3(obj.aabb[1])