Improved Corners with Multi-Channel Signed Distance Fields
Computer Graphics Forum 37(1):273-287, 2018
We propose an extension to the state-of-the-art text rendering technique based on sampling a 2D signed distance field from a texture. This extension significantly improves the visual quality of sharp corners, which is the most problematic feature to reproduce for the original technique. We achieve this by using a combination of multiple distance fields in conjunction, which together provide a more thorough representation of the given glyph’s (or any other 2D shape’s) geometry. This multi-channel distance field representation is described along with its application in shader-based rendering. The rendering process itself remains very simple and efficient, and is fully compatible with previous monochrome distance fields. The introduced method of multi-channel distance field construction requires a vector representation of the input shape. A comparative measurement of rendering quality shows that the error in the output image can be reduced by up to several orders of magnitude.