Lighting in OpenGL

Tom Kelliher, CS 320

Apr. 18, 2005

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Take-home exam. When? You're ready now.

Assignment

Read 6.7--9 (6.1--5).

Do/finish the lab, run lightLab.c with flat shading rather than smooth shading.

From Last Time

Finished Phong light model.

Outline

1. Walk-through of lighting calls in lightLab.c.

2. Lighting lab.

Coming Up

Continuation of lab.

Lighting in OpenGL

Pertinent functions (line numbers refer to code handout):

1. glShadeModel() (269): GL_SMOOTH, GL_FLAT

2. glMaterial*() (271--274):
   1. Face: GL_BACK, GL_FRONT_AND_BACK

   2. Parameter name:
      1. Shininess range: 0--128.

      2. GL_AMBIENT_AND_DIFFUSE

      3. GL_EMISSION

   3. Parameter: scalar for shininess, vector for other parameters.

3. glLight*() (145, 276--278):
   1. Light: 8 lights.

   2. Parameter name: see man page for other names

   3. Parameter: some scalar, some vector.

      The fourth value in a light's position.

4. glEnable() (280--285):
   1. GL_LIGHTING

   2. GL_LIGHTx

   3. NORMALIZE

   glDisable()

These are all modal.

Can turn lighting on and off.

Normal normals and non-normal normals.

Hands-On Lab

Grab a copy of lightLab.c from class Web page and begin experimenting.