Orca3D News

Tuesday, December 2, 2008

Make it easier to see the control points on a surface

While working in Rhino, sometimes the view can become cluttered, making it difficult to see the part of the model that you're interested in. This can be particularly true when fairing a hull; for example, when working in the Right or Bodyplan viewport and moving control points in the bow, the aft portion of the hull clutters the view.

One solution to this is Rhino's clippingplane command. A clipping plane is a plane in space beyond which any geometry becomes invisible. Clipping planes are specific to a viewport, and any viewport may have multiple clipping planes.

To create a clipping plane, type the command clippingplane into Rhino's command line (it's not available in a menu, but there is an icon on the Viewport Layout toolbar). Click in the viewport in which you want the clipping plane to apply, and then draw a rectangle (the size of the rectangle doesn't matter; the clipping plane is infinite). Now, drag the clipping plane in one of the other viewports to change its location. The clipping plane has a pointer that shows the direction of the visible geometry. Use the flip command to turn it around. By turning on the control points of the clipping plane, you can rotate the plane, and drag it to dynamically clip the view.

A second option to make it easier to see your control net is the cullcontrolpolygon command (the icon is available on the Point Editing toolbar). This command, which is a toggle, hides any portion of the control polygon (the lines connecting the control points) that are in the background. This is easily seen in the Perspective viewport as you rotate the hull with the Orca control points on.

Rhino's Right view will now show just the aft portion of the control polygon (assuming forward is negative X in your model), and the Bodyplan view of the Orca3D viewports will show the forward portion of the control polygon.