matrix_build_projection_perspective

This function builds a perspective projection matrix based on the dimensions of the near clipping plane, using the specified parameters listed below.

Note that the field of view of the camera will vary depending on the width, height and znear values specified, as the projection width and height are placed at the Z position specified in the znear argument.

For example, given a constant size of 640x480, the field of view will be wider if znear is closer to the camera, but it will be narrower if znear is far away from the camera. This behaviour is demonstrated in the following visual:

Due to this, it is recommended to use a znear value that is identical to the width of the projection, resulting in the field of view being consistent with an equivalent orthographic projection.

Syntax:

matrix_build_projection_perspective(width, height, znear, zfar);

Returns:

Matrix Array

Example:

var projmat = matrix_build_projection_perspective(640, 480, 640.0, 32000.0);
camera_set_proj_mat(view_camera[0], projmat);

The above code creates a perspective projection and then uses the matrix returned to set the camera assigned to view port[0].