Today, I managed to perform contour/suggestive contour rendering in imagespace – thus working on a rendered diffuse shaded image. After using the Sobel edge detection filter to detect regular contours, I looked for an efficient algorithm to detect valleys and creases, in order to draw suggestive contours as well. As …
After squashing a rather nasty bug this morning (GLSL shader memory alloc is tricky), I made some renders to demonstrate the algorithm. The algorithm is an object-space algorithm. This has some implications: Operations are performed with direct vertex info. No intermediate rendering+signal filtering is done. Rendering it on the GPU …
I don’t know what just happened to my shader, but this sure looks funky.
Because my current Suggestive Contours/Suggestive Highlights implementation is written using OpenGL calls for rendering, it was best to start work on the vertex/fragment shaders for a GPU implementation in the OpenGL shading language (GLSL). This would reduce OS/Platform dependency too. Another option was using Nvidia’s Cg, which claims to be …