I decided at some point in the last couple of weeks that I wanted to put together a site that would look at some of the real-time computer graphics gems that I’ve either created or come across in my work. RenderLoupe is the culmination of this desire.
Why “RenderLoupe”? Well two reasons:
- To anyone knowledgeable about computer graphics, there’s an obvious play on words here with “render loop”.
- Since we’re going to be looking at things, and perhaps scrutinizing them, the idea of looking at things through a loupe really appealed to me.
To start off with, just to whet your appetite, I have links to a couple of sites that allow you to write GLSL in the browser:
- ShaderToy (a lot of times this is a very slow loading site, so be patient!)
- GLSL Sandbox Gallery
On ShaderToy, I wrote a couple of simple shaders to get started – if you’re interested in seeing “what is possible” in the browser, there are a lot of great examples. The first one I wrote is an edge detection shader, which uses matrix convolutions, such as the Sobel kernel, to highlight places in the image where there is a significant change in luminance from one pixel to another. I decided to include a number of other kernels as options. The shader source is documented, so here you go:
I also wrote a shader that casts rays at a sphere in real time. You can drag the mouse and the eye/viewpoint will update accordingly:
