Is it difficult to add a clash detection feature in Rhino7?


Clash detection is a common problem for architects, and I notice that intersections in R6 are quite reliable.

Basically a clash detection report is made up of a list of all objects intersecting intersecting each other.

So if you can add this in R7 i think many people will use it.

Select objects, Intersect, Zoom Selected.

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I mean like a proper clash collision interface that can produce also a report. (the intersect part I know, as I said already, it is quite reliable)

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That’s usually BIM stuff. I dont think Rhino is trying to be a BIM software. However, maybe VisualARQ has stuff like a clash report.

What would this report look like?

Did you try “Clash”?

I’m not sure what the SDK function returns, but I’m guessing with a bit of python it can have any UI you might need.

@lowell can help.


Hi @stevebaer ,

It takes each element in a building and it intersects it with all the rest. This is quite heavy computing so sometimes it’s done in the cloud.

Once all intersections have been solved it creates a list for each element with the intersections.

Like wall-ID-xxx is intersecting with floor-ID-xxx, with ceilng-ID-xxx, etc etc, etc.

So then designers know if they missed anything.

So let’s say, for example in Rhino after a clash detection there could be listed in the attributes of every object the intersecting others

Cool! I didn’t knew that, thanks!
This command is one of those good ones that are not advertized at all.
If it could produce a list it could be even a brawsable list. where for each element there’s a dropdown button listing all interesections.

I need to learn some UI programming in rhino for this.

I also have to mention that clash detection software might get quite expensive sometimes.

I don’t think there’s much in Rhino common about Clash.
Just looking at what I can find there, it looks like you can find the intersections of 2 meshes and get back the location and size of intersect events.
The Rhino Clash command does a bunch of organizing of groups of objects and lists of results, but I don’t see any of that exported. (I could be missing something.)

It sounds like the main concern is ease of organizing the results, not speed of the intersections. I can’t see any of that exported. Maybe Clash won’t really apply here without extra programming.

The benefit of the Rhino Clash stuff is intersection speed in big models. It uses FastRenderMeshes of the objects and does some fancy spatial decomposition sorting and finds intersection locations fast.
It doesn’t return any nurbs intersection information.

Hi @lowell ,

I don’t really need nurbs intersection information. I only need a list of intersecting geometry.
For each object, a list of intersections, with the object ID’s

Also I cannot find examples of UI programming.

Here are examples how to code ui in python in rhino:

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thank you!

HI @Bogdan_Chipara,

The MeshClash.Search methods are pretty simple and straight forward to use. I’ve attached a simple Grasshopper solution that uses a C# component as a demonstration. (26.1 KB)

– Dale

@Bogdan_Chipara and everyone on this thread,

We added a Clash detector in Grasshopper component in addition to the RhinoCommon method for Clash. Here is some evolving documentation on the feature.

We are looking for feedback on the methods:

  1. Does it find the clashes you need?
  2. Is it fast enough?

Another really fun part about Clash is that it will work on Revit elements using Rhino.Inside.Revit


Hi @scottd and everyone.
I’m happy to see such interest on this topic(I was not expecting)
I’m not working in later stages lately so I haven’t had time to test.

In my opinion this feature should be advertised. Might be very useful for small firms that are not willing or don’t need to invest in a complex clash detection software. It might also be useful in smaller projects that can be done without BIM.

I will check more on this topic…

OK, here is a fun one. Using the Clash component in Grasshopepr running in Revit, then creating a CSV report on the clash including the Revit Element ID for each clash.


this is amazing!

do you mind sharing the gh file?

I know that some of the icons are temporary and it’s a detail, but please make those icons different. There might be more silly people out there (than just me) who can easily confuse them and wonder why it is not working.