Revision as of 18:09, 22 November 2014

Project 6: Simple Water

This project is on Bezier patches, texturing, and environment mapping with a GLSL shader program. The goal is to create a Bezier patch, make it resemble a water surface with small waves, then put it in a textured environment cube and render its surface with environment mapping.

It is due on Friday, December 5th at 3:30pm and will be discussed in CSB 001 on Monday, December 1st at 5pm.

1. Make a Bezier Patch

Generate the 16 control points for a cubic Bezier patch. Put them all in the x-z plane (horizontal), since the patch is going to simulate water.

Tessellate the patch out of GL_QUADS: use uniform sampling to calculate 3D points on your patch on a regular grid. We suggest using around 100x100 quads to produce a smooth surface.

Connect the points with GL_QUADS in counter-clockwise order to form a surface, and calculate normals. Give the quads a color and material of your choice.

Tip: You can compute normals as follows: Given the Bezier curve (x(t),y(t),0) in the x/y plane, you first compute the tangent vector (x'(t),y'(t),0). The corresponding 3D normal vector is then (-y'(t),x'(t),0), which you rotate around the y axis similar to the vertices. Don't forget to normalize the normal vectors.

Enable at least one light source and position it so that it nicely illuminates the patch.

2. Animate the Patch

Use sine and cosine functions to move the control points of your patch up and down, to simulate a water surface.

3. Add an Environment

4. Use Environment Mapping

5. Optional: TBD