Are you planning to support Rhino’s Clipping Planes in a way that they produce sections with patterns?
Clipping planes are handy to push around and level cut plane height is something I would like to not modify that often.
On food4rhino are some tries to make clipping box for Rhino but (some/all) of them are just workarounds with hidden clipping planes. There are a lot of asks for that from Rhino users.
A proper solution to that (with some good modify widgets as in other VA geometries) would be much welcomed.
If something like that would be implemented, could this clipping geometry be something other than 6 infinite cutting planes, please?
For example: Could geometry shaped like this become a clipping geometry?
Yes, and no. We have internally discussed about this several times. The problem is that we don’t want to interfere with Rhino clipping planes, as other plug-ins, and Rhino itself, may use clipping planes for something, and drawing a hatch pattern may break something.
Probably we will end creating our custom clipping planes, that will be just like the Rhino ones but created with a different command vaClippingPlane. Or maybe we can add a toggle on the clipping plane properties panels to enable section patterns for this particular clipping plane.
Regarding your screenshot, there is a known bug in our “Hidden” display mode, that is not even showing the section lines for clipping planes.
VisualARQ does support this kind of section geometry. We call it internally “section volumes”. They need to be planar (curved surfaces are not supported yet). What we do is slipt the section geometry into convex pieces. Then, using multi-pass rendering, we render the scene activating one single section piece (using one clipping plane for each section face) for each pass. This is used for example in jogged sections like this one:
There is also a limit in the number of active clipping planes supported by OpenGL: 6 or 8 depending on the driver, so some convex pieces will need to be partitioned again until they have 6/8 faces. There could be more active clipping planes using OpenGL shaders, but Rhino plug-ins have no SDK access to extend OpenGL shaders currently.
