.. title: CG Class 26, Thu 2019-12-05 .. slug: class26 .. date: 2019-12-05 .. tags: class .. category: .. link: .. description: .. type: text .. has_math: true .. sectnum:: .. contents:: Table of contents No class on Mon Dec 2 ---------------------- Snow day. Student fast forward presentations ---------------------------------- part 1 OpenGL in Guha vs WebGL in Angel -------------------------------- #. Guha, the text I used before Angel, uses OpenGL. Angel uses WebGL. #. OpenGL has a C API; WebGL uses Javascript. #. That OpenGL is the obsolete version 2; WebGL is based on the current OpenGL 3. #. OpenGL 2 has an immediate mode design: you draw things and they are forgotten. In WebGL you send buffers to the GPU and then draw them. #. OpenGL has compute shaders and geometry shaders. They fill in points along Bezier curves and draw trimmed NURBS. #. A NURBS surface is a 2D parametric surface in 3D (or 4D if homogeneous). A trim line is a 1D parametric curve in the the 2D parameter space of the surface. The trim lines cut around the outside of the desired region and also cut out holes. This is a powerful technique. Chapter 15 slides --------------------- #. You do not need to learn most of those slides. Later I'll summarize what you need. #. `15_1 Global rendering `_. #. `15_2 Ray tracing `_. #. `15_3 What's next? `_. Introduction to GPUs -------------------- from `UT Computer Science `_ .. used up to 2018 class 27