docs: public static GrayU8 createMask( CameraUniversalOmni model ,
  									 LensDistortionWideFOV distortion , double fov ) {
  		GrayU8 mask = new GrayU8(model.width,model.height);
  
  		Point2Transform3_F64 p2s = distortion.undistortPtoS_F64();
  		Point3D_F64 ref = new Point3D_F64(0,0,1);
  		Point3D_F64 X = new Point3D_F64();
  
  		p2s.compute(model.cx,model.cy,X);
  
  		for (int y = 0; y < model.height; y++) {
  			for (int x = 0; x < model.width; x++) {
  				p2s.compute(x,y,X);
  
  				if( Double.isNaN(X.x) || Double.isNaN(X.y) || Double.isNaN(X.z)) {
  					continue;
  				}
  
  				double angle = UtilVector3D_F64.acute(ref,X);
  				if( Double.isNaN(angle)) {
  					continue;
  				}
  				if( angle <= fov/2.0 )
  					mask.unsafe_set(x,y,1);
  			}
  		}
  		return mask;
  	}