Real-time animation of amorphous phenomena

We present a technique to animate amorphous materials such as fire, smoke and dust in real-time on graphics hardware with dedicated texture memory. Our method uses a coarse voxel grid to model object dynamics, and texture cycling to create local and global dynamics. Detail is added by encoding high-frequency components, which are normally spread uniformly throughout the volume, into the volume integration. The individual voxels are rendered using a splatting approach with a table of anisotropic footprint functions. Our method produces a truly three-dimensional volume effect that can interact with the rest of the environment.

Using different spectral scales for the volume's appearance allows for motion at three distinct and disjoint scales. Local dynamics are achieved by phase-shifting through a set of textures within a voxel. Global dynamics, such as eddies, are propagated through the volume using inter-voxel dynamics. Object dynamics are achieved using procedural or keyframe animation techniques on the low-resolution voxel grid. We also develop an automated technique for texture selection by sampling a single large image having various frequency components.

Keywords: Fire, smoke, clouds, gaseous phenomena, volume rendering, atmosphere, splatting, textured splats, animation.

Project Members

Dr. Roger Crawfis, Assistant Professor - Project Lead.
Scott King, Ph.D. Student
Wayland Reid, grad student.
Jason Lescaleet, grad student.

Images

Volume Graphics 99 support page.

Software

Download a demo version, Fire1.0.0b.tar.gz (6101037 bytes), compiled for IRIX 6.2. You will need a machine with dedicated texture hardware (ONYX/IR, Octane/MXI ...), but an 02 will give you decent performance. The distribution contains some sample inventor files, the DSOs and some texture files. Look at the file README for instructions.

References

Scott A. King, Roger A. Crawfis, Wayland Reid, "Fast Animation of Amorphous and Gaseous Phenomena", Volume Graphics '99, Swansea, Wales, pp 333-346, March 1999.
709754 byte PDF

Scott A. King, Roger A. Crawfis, Wayland Reid, "Fast Volume Rendering and Animation of Amorphous Phenomena", chapter 14 in Volume Graphics edited by Min Chen, Arie E. Kaufman and Roni Yagel, Springer, London, 2000.

Created Jan 23, 1999 by Scott King