Delete invisible parts of curve / Extract visible parts

Hey everybody!

Is there a way/command to remove the parts of a curve which are not visible from some camera point (as other objects are in front of them)?

I projected a line along the viewing perspective onto several breps and now I want to extract only the parts of the projected curves which are actually visible from the current camera point and delete the invisible parts - I am using the embedded Python script editor.

I am quite a novice in Rhino…


Hi Raphael,

What exactly are you trying to do and why?

Can you post some sample geometry that show the ‘before’ and ‘after’ you are looking for?

– Dale

Alright, here is a picture trying to explain what I want to achieve:

I projected the line onto the two planes along the viewing perspective (rotated the view for the picture because otherwise the projection line would be in front of the projections) and now I want to remove the hidden part of projection 2. As the result of my script I want to get two curves: the whole first projection and the (from the viewing point from which the projection was made) visible part of the second projection as a separate curve.

Hope this explanation suffices to show my problem.


@pascal, any ideas?

Nothing really straightforward or easy comes to mind… I’m thinking of things like projecting the border curves and the input curves to the view plane, cutting up the planarized input with the border curves and then projecting the pieces.


Hmmm, ok - I will try to look into the mentioned approaches.

Thanks for helping.