Non-Photorealistic Fire

							Non-Photorealistic Fire


      Mike Donovan
My Project

   Video game fire does not act
    realistically.
   Fire lags behind other graphical
    aspects.
   Powerful hardware makes it possible
Oblivion
Sprite
My Project

   Is it possible to accurately model fire
    while maintaining interactivity?

   Can we then take this model and
    extend it to a non-photorealistic
    rendering?
Overview

   Mathematical Basis
   Expand to something spatial
   Add the texture
   Non-photorealism
   Applications
Mathematical Model

   Beziér spline.
Spline Lattice

   Built lattice around spline
   Flat squares
Alter Spline Lattice

   Currently, the lattice has
    uniform upward normals.

   To add realism, the
    lattice should “bend” with
    the spline.
Derivatives

   Done using the line
    perpendicular to
    the derivative of the
    spline.
Physical Model

   Create a realistic model of fire
    including
       Wind
       Velocity (flicker)
       Fuel
   This creates an even more realisitic
    acting fire
Texturing

    2D Texture used for fire
    Changes to the texture will change the fire




    Fuller et al. 2007
What is non-photorealism?

   Rendered in a distinctly not realistic
    fashion.
   Has a cartoon look and feel
   Limited palette of colors
Team Fortress 2
Non-photorealism

   Few colors in texture lead to fire
    having limited colors
   Transparency and blending cause a
    uniform color in the middle while
    allowing for different colors on the
    fringe.
Applications

   Many different ways to use the simple
    Flame object:
       Single flame candle
       Multiple flame torch
       Sprawling brush fire
Conclusions

   One texture for all flames and simple
    mathematical model allows for great
    scalability and performance.
   A single implementation of the flame
    allows countless applications of fire.
Questions?