# Point Light Example

## Vertex Shader Processes Lighting

### Swipe to Spin the Shaded Cube

View this simplified example of a point light on a cube. The vertex shader calculates lighting. The cube is mapped with a solid color blue. Lighting helps define the shape of the cube. Light location, light color, and ambient color are all declared with constants in the vertex shader, to keep this example simple. See the Point Light Tutorial with source code.

Seven Thunder Software created a cube in 3DS Max then exported as a DAE file with normals. The JavaScript DAE Translator to converted DAE data for use with WebGL. The JavaScript for this example uploads an attribute with normal coordinates per vertex. Each animation frame uploads a normal matrix. The normal matrix is a 3 x 3 matrix derived from the inverted and transposed model matrix.

As the cube spins and moves, both a model matrix and a normal matrix are uploaded. The vertex shader uses the normal attributes and normal matrix to compute lighting per frame.