C# COM API: Intersection / Interference of Solid and Surface

[Anonymous]

Hi,

I want to control AutoCAD via the COM API in C# (an out-process app) and get possible intersections / interference objects of an AutoCAD.AcadSurface and AutoCAD.Acad3DSolid.

I tried several methods but none works:

• Acad3DSolid.CheckInterference(AcadSurface, false, out bool interference) => won't compile because this method only wants to take another 3dSolid
• Acad3DSolid.Boolean() => same as above
• AcadSurface.IntersectWith(Acad3DSolid, AutoCAD.AcExtendOption.acExtendNone) => exception from HRESULT: 0x80200001
• Acad3DSolid.IntersectWith(AcadSurface, AutoCAD.AcExtendOption.acExtendNone) => throws an exception: "Not yet implemented"

In .NET API (in-process) there is a method Surface.createInterferenceObjects() (see here: https://forums.autodesk.com/t5/net/solid3d-checkinterference-overload-with-other-entities-e-g/m-p/82...)

In C++ ObjectARX there is also a method AcDbSurface::createIntereferenceObjects() (see here: https://knowledge.autodesk.com/search-result/caas/CloudHelp/cloudhelp/2017/ENU/OARXMAC-RefGuide/file...)

Is there a way to do this in COM API in C#? I would be very happy if someone could help me. Many thanks in advance.

I use AutoCAD Mechanical 2019 and Windows 10.

[Alexander.Rivilis · Accepted solution]

---

@Anonymous wrote:

Is there a way to do this in COM API in C#? I would be very happy if someone could help me. Many thanks in advance.

---

Sorry for bad news but in COM API there is no methods for that. But you can create arx-plugin, load it into AutoCAD and communicate with it.

AcDbSurface::createInterferenceObjects and AcDbSurface::booleanIntersect methods can help you.

[Anonymous]

Thank you very much for your quick answer.

I will try to use another solid instead of a surface then.

I chose to use the COM API instead of the .NET API (for an in-process app) because it gives me full control over AutoCAD. What I need to do is insert a solid and get the return value from the interference method and I prefer to let my out-process app control the inputs and outputs instead of handing it over to AutoCAD, executing a custom command and then reading some user variable. (I tried this and find it a bit unsatisfying.)

And I don't know any C++ yet.

[Alexander.Rivilis]

1. AutoCAD COM/ActiveX API has not been developed for more than 10 years.

2. Out-process is much slower than In-process

I think in your case you can use AcCoreConsole. You can start it from your external application and load .NET-plugin into it to use all functionality of AutoCAD .NET API instead of COM API. This is the fastest and most effective method. IMHO.