protected Vector3 ndcMouseToWorld(Vec2 ndcMouse) {
        return pvMatrix.ndcToWorldCoordinates(ndcMouse.dx, ndcMouse.dy, getTargetPlaneDistance());
    }
Renders a viewport within the node frame. Overrides provided to obtain the camera position fov, etc.
core/src/main/java/mrtjp/projectred/redui/ViewportRenderNode.java