OpenGL GraphicsTextures

QuizYou didn't see that coming!

1. What is OpenGL?

2. What is a vertex?

3. What are the three steps to render with depth testing?

4. What is the difference between an orthographic and a perspective projection matrix?

5. What are the three components of the fixed functionality lighting model?

Textures

What is a Texture?

Image applied to geometry

.tga, .jpg, .png files

1, 2 or 3 dimensional!

Texture Coordinates

Vertex attribute

Values between 0 and 1

1, 2 or 3-dimensional

OpenGL will interpolate between the vertices

Texture Triangle

Sampling Textures

Exceedingly rare that the texture will fit the geometry exactly

We need a way of mapping to the best representative texel

Nearest-neighbour filtering

Bilinear filtering

Mipmaps

Used to improve the sampling quality

Used to improve the sampling quality

Mipmaps

Can specify mipmap level when loading a texture into OpenGL

glGenerateMipmap()

Trilinear filtering

OpenGL Texture Objects

Stores a texture in GPU memory and holds texture properties

glGenTextures()

glBindTexture()

glTexImage2D()

glTexParamf()

glDeleteTextures()

Demo

Questions?