title: What extractly mat3(a mat4 matrix) statement in glsl do?
body: <p>I'm doing a per fragment lighting and when correcting normal vecter, i got this code: <code>vec3 f_normal = mat3(MVI) * normal;</code> Where MVI is: <code>mat4 MVI = transpose(inverse(ModelViewMatrix));</code>. So what is return after <code>mat3(MVI)</code> statement?</p>