public void setPerspectiveView(float fov, float aspectRatio, float near, float far) {
        float radians = (float) Math.toRadians(fov * 0.5f);
        float coTan2 = (float) (1.0f / Math.tan(radians));
        float yScale = coTan2;
        float xScale = yScale / aspectRatio;

        projMat.set(0, xScale);
        projMat.set(1, 0.0f);
        projMat.set(2, 0.0f);
        projMat.set(3, 0.0f);

        projMat.set(4, 0.0f);
        projMat.set(5, yScale);
        projMat.set(6, 0.0f);
        projMat.set(7, 0.0f);

        projMat.set(8, 0.0f);
        projMat.set(9, 0.0f);
        projMat.set(10, far / (near - far));
        projMat.set(11, -1.0f);

        projMat.set(12, 0.0f);
        projMat.set(13, 0.0f);
        projMat.set(14, near * far / (near - far));
        projMat.set(15, 0.0f);
    }