With virtual reality, digital painting on 2D canvas is now being extended to 3D space. In this paper, we generalize the 2D pixel canvas to a 3D voxel canvas to allow artists to synthesize volumetric color fields. We develop a deep and dynamic octree-based painting and rendering system using both CPU and GPU to take advantage of the characteristics of both processors (CPU for octree modeling and GPU for volume rendering). On the CPU-side, we dynamically adjust an octree and incrementally update the octree to GPU with low latency without compromising the frame rates of the rendering. Our octree is balanced and uses a novel 3-neighbor connectivity for format simplicity and efficient storage, while allowing constant neighbor access time in ray casting. To further reduce the GPU-side 3-neighbor computations, we precompute a culling mask in CPU and upload it to GPU. Finally, we analyze the numerical error-propagation in ray casting through high resolution octree and present a theoretical error bound.


  • Interactive adjustment of a large octree in a CPU for painting
  • Strategies to perform adaptive painting strokes and distributed grid adjustment over multiple time steps
  • Incremental, low-latency octree update to the GPU without adverse impact on the already GPU-intensive volume rendering
  • New and simple octree neighbor connectivity with only three connections per cell for fast traversal to neighboring cells
  • Numerical error propagation analysis during ray traversal on a high-depth octree
  • Novel 3D volumetric field painting effects such as color pick-up and color mix with adaptive grids




Thanks To

Daichi Ito
Jini Kwon
Yunhyeong Kim
Jaehyun Kim