Question:

I have a simple scene in WebGL where i store every transformation (for the camera and the models) in a single model/view matrix and i set them by rotating and moving said matrix.

What i want is, to being able to rotate the camera around and when i "move forward" to move towards where the camera is pointing.

So far, i have modified this code to this:

    mat4.identity(mvMatrix);    
    mat4.rotateX(mvMatrix, degToRad(elev), mvMatrix);   
    mat4.rotateY(mvMatrix, degToRad(ang), mvMatrix);   
    mat4.rotateZ(mvMatrix, degToRad(-roll), mvMatrix);  
    mat4.translate(mvMatrix, [-px, -py, -pz], mvMatrix);

since it wasn't working as it was and it kind of works, until you do an extreme rotation (more than 90 degrees).

This is not a deal breaker for what i'm doing, but i want to know. Is this the best i can get without moving away from calculating the camera orientation like this?

Answer:

WebGL cameras generally point down the -Z axis so to move in the direction the camera is facing you just add the camera's Z axis (elements 8, 9, 10) to the position of the camera multiplied by some velocity.