glsl-ruler
Helper module for debugging raytraced SDFs inspired by Johann Korndorfer's "How to Create Content with Signed Distance Functions" talk at NVScene 2015.
Thanks to Ryan Alexander for his example implementation on Shadertoy ✨
Usage
trace = require(glsl-ruler/trace, <map>, <steps>)
Currently, glsl-ruler
needs to handle raytracing on your behalf – it does so using an API very similar to glsl-raytrace. For further details, check out that project's documentation.
vec3 trace(vec3 ro, vec3 rd)
The key difference here between glsl-ruler/trace
and glsl-raytrace
is that instead of returning a vec2
, trace
will return a vec3
with the elements corresponding to:
- The signed distance value retrieved from a raytrace of your
map
function merged with the ruler plane. - A second attribute for assigning an ID to surfaces. This will be
-1.0
if the ray hit the plane. - The signed distance value retrieved from a raytrace of only
your
map
function. You can then use this to color the plane.
color = require(glsl-color)
vec3 color(float distance)
Returns an RGB color for the plane based on the distance
value of your signed distance field.
Example
By combining the above two modules together, you can quickly tweak existing glslify-driven raytracers to debug and explore 3D SDFs:
vec2# camera = require('glsl-turntable-camera')# trace = require('glsl-ruler/trace', map = doModel, steps = 90)# color = require('glsl-ruler/color')// creates a unit sphere at the originvec2void
For a full example, see demo.frag.
Contributing
See stackgl/contributing for details.
License
MIT. See LICENSE.md for details.