topic Re: Check intersection between Solid objects in Revit API Forum

Check intersection between Solid objects

giancarlo.web — Tue, 17 Oct 2017 11:38:50 GMT

I tried using

var unionvolume = BooleanOperationsUtils.ExecuteBooleanOperation(solid1, solid2, BooleanOperationsType.Union).Volume
                        if (solid1.Volume < unionvolume)
                        {
                            //Do something
                        }

but it looks like it somehow merge those two solids even if they are miles away.

BooleanOperationsType.Intersection/Difference doesn't work either since i need even touching solids

is there a solution to this problem?

Also a BoundingBox is not a solution since i may have complex shaped stuff

Re: Check intersection between Solid objects

FAIR59 — Tue, 17 Oct 2017 14:58:29 GMT

Using a combination of Intersect and union gives you a pretty good answer. If the solids touch at an edge this will return [not intersecting, not touching] instead of [touching].

			Solid interSolid = BooleanOperationsUtils.ExecuteBooleanOperation(s1,s2, BooleanOperationsType.Intersect);
			if (Math.Abs( interSolid.Volume)>0.000001) 
			{
				TaskDialog.Show("debug", "intersecting");
				return;
			}
			Solid unionSolid = BooleanOperationsUtils.ExecuteBooleanOperation(s1,s2, BooleanOperationsType.Union);
			double dArea = Math.Abs(s1.SurfaceArea+s2.SurfaceArea -unionSolid.SurfaceArea);
			if (dArea< 0.00001 && s1.Edges.Size+s2.Edges.Size == unionSolid.Edges.Size)
				{ TaskDialog.Show("debug","not intersecting, not touching"); }
			else{TaskDialog.Show("debug","touching");}

Re: Check intersection between Solid objects

danielpinheiro860 — Fri, 21 Jan 2022 15:04:32 GMT

Very great solution!

Just to contribue with the situation, I've created another kind of analysis based on the above method and its works very well on my workflow, I am just sharing with you below just for the sake of contribution in some way:

Solid unionSolid = BooleanOperationsUtils.ExecuteBooleanOperation(solid1, solid2, BooleanOperationsType.Union); Solid interSolid = BooleanOperationsUtils.ExecuteBooleanOperation(solid1, solid2, BooleanOperationsType.Intersect); double sumArea = Math.Round(Math.Abs(solid1.SurfaceArea + solid2.SurfaceArea), 5); double sumFaces = Math.Abs(solid1.Faces.Size + solid2.Faces.Size); double unionArea = Math.Round(Math.Abs(unionSolid.SurfaceArea), 5); double unionFaces = Math.Abs(unionSolid.Faces.Size); if (sumArea == unionArea && sumFaces == unionFaces && interSolid.Volume < 0.00001){TaskDialog.Show("debug", "not touching, not intersecting"); else if (sumArea > unionArea && sumFaces > unionFaces && interSolid.Volume > 0.00001) {TaskDialog.Show("debug", "intersecting"); } else if (sumArea > unionArea && sumFaces > unionFaces && interSolid.Volume < 0.00001) {TaskDialog.Show("debug", "touching");}