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Martin Prazak edited this page Oct 7, 2018 · 19 revisions

Welcome to the Possumwood wiki pages!

Wiki pages for Possumwood are intended primarilly for tutorials and code examples. Please feel free to contribute!

Tutorials

Introduces basic concepts of GLSL shaders in Possumwood, via a simple setup displaying a rotating car. Its model is loaded from an .obj file, converted to an OpenGL Vertex Buffer Object and displayed using a combination of a vertex and a fragment shader.

A simple GLSL skybox setup, using fragment shader and the background node (based on gluUnProject) to render a background quad with spherically-mapped texture.

Environment map is a simple technique to approximate reflective surfaces in GLSL, without the need of actual raytracing. This tutorial builds on the previous Skybox tutorial, and extends it to make a teapot's material tool like polished metal.

Most implementation of OpenGL 4 remove the ability to influence the width of lines using the classical glLineWidth call. This tutorial describes in detail how to achieve a similar effect (and much more) using a geometry shader, by rendering each line as a camera-facing polygon strip.

Implementation of Curved PN Triangles tessellation technique, presented by Alex Vlachos on GDC 2011. This method tessellates input triangles using solely their vertex positions and normals (independently of the mesh topology) in a geometry shader.