Further to this thread about managing complex foundations and how they interact with my topography, I wanted to propose a couple of feature requests to improve the workflow for this sort of work.
Cutting Objects
Allow users to set a solid as a “cutting object” so that when it touches another solid, it automatically does a Boolean difference. What is crucial to this is that if you move or delete the cutting object, the object that is being “cut” goes back to its original state instead of being permanently deformed. For even more flexibility you could add a toggle to set whether objects are “cuttable” (kind of like the setting that lets you set whether an object can cast or receive shadows). This would make working with complex foundations infinitely easier than having to manually cut and permanently mess up the polysurface every time there is a change.
As i am typing this it occurred to me that you would also need to account for the hollow spaces underneath ground level, like basements or voids, which still need to be “cut out”. In Revit, slabs basically cut everything from their lowest point upwards. Perhaps something like “boolean all above” could also be set as a toggle. Food for thought!
Reshape Surface to Point/Curve
This one is about surfaces or, in my case, the face of solids. Modifying topography right now is a huge pain because it’s incredibly hard to get both precision and smooth transitions at the same time. To get smooth transitions, you have to drop the point count right down so you can push and pull points around, but that makes everything low resolution and you lose control over sharp details.
The most common issue is when I need to cut and fill terrain for something like a meandering path or a road over rolling landscape. Trying to do that by manually moving points is nearly impossible. A feature that would actually make this work is letting us sketch out the boundaries of these new shapes using points and curves, and then allowing us to “integrate” them directly into the surface. That way, Rhino can do what it does best: interpolate the transitions to create a clean, sweeping terrain that follows the lines you’ve drawn. It occurred to me that with this workflow you might run into awkward conflicts/tensions between existing surface points and the new reference lines, so perhaps a setting to give the new objects priority over the surface points might resolve this.
I hope this is all clear. I have been struggling with this for some time and I’m still trying to resolve the best way to achieve what i require with the maximum efficiency (my current workflow is definitely not efficient!).
Please let me know if anything i mention needs clearing up and I’ll do my best to explain.
Thanks for the writeup, this is a well thought out pair of requests.
For the cutting objects part — a good chunk of this already exists. Turn on Record History in the status bar, then run BooleanDifference with DeleteInput=No. The cut result stays linked to the inputs, so if you move or edit the cutting solid the cut updates automatically. Keep the original topo and cutters on an off layer and you never permanently damage the polysurface. This came in with Rhino 8:
It’s not a persistent “cutting object” property like Revit voids but it gets you the non-destructive workflow — worth a try before we go further on that one.
The reshape-to-curve request is a real gap, i don’t believe we have anything today that integrates new points/curves into an existing surface with smooth transitions. There is an older open request for terrain tools that respect input curves better, and i’ve added a new request for the integrate/reshape workflow you describe:
Thats a great technique with Boolean Difference that i wasn’t aware off and it will largely solve one part of my problem. I don’t fully understand the concept of object history and i notice that when i deleted the cutting object it give me an error saying that i had broken the history but i will look into this on my end and experiment a bit. For what its worth this is a “hack” of sorts and it wouldn’t hurt to give cutting objects its only category which can be fleshed out and given some scope. For example the issue of the air voids still exists.
Terrain tools integrated into Rhino would be a dream. I would throw my weight behind that any way i could. Are there any open threads in the forum where there is a back and forth about potential inclusions?
