Introduction
This program aims to visualise the difference between traditional and hue preserving color blending described in Chuang et al. The comparison is done through a lerp functionality that flicks between the two blending modes, and the user can also compare different data sets. The algorithm preserves the original hue of the blended colors and therefore gives a clearer visualisation of nominal data since the colors are more contrasted. A bias function is also implemented to avoid gray colors that come from blending different colors and instead use the more saturated color values.
Usage
We predesigned a few datasets and their transfer textures for the user to explore. There are two kinds of bias functions:
- Lerp between traditional and hue-preserving blending. This kind of "bends" the regular blending curve towards hue-preserving blending.
- Bias only affects hue-preserving blending. This causes the color to stay more in the saturated part.
Implementation
Implementation is done in Unity3D via GPU-based front-to-back volume raycasting. The most important files to look at are Volume.shader and functions.cginc.
