topic Re: Broken Mesh with TessellatedShapeBuilder in Revit API Forum

Broken Mesh with TessellatedShapeBuilder

Anonymous — Thu, 25 Jan 2018 10:16:57 GMT

I am trying to create a mesh in Revit using TessellatedShapeBuilder, with the mesh data coming in from a different data model. I am creating faces and adding the faces to the shapebuilder. Please see the code attached.

In the end I add the mesh to the document using DirectShape. And the resulting mesh looks as shown in the picture. Why is the mesh all broken ? The source mesh is normal looking.. looks like a spaceship, but this one is broken. I thought maybe it has something to do with face normals ? Or is there some behavior of tessellatedshapebuilder that I am missing ? What am I doing wrong ?

Re: Broken Mesh with TessellatedShapeBuilder

jeremytammik — Thu, 25 Jan 2018 10:29:03 GMT

I guess there are a lot of things you might be doing wrong.

No idea what they may be.

I cannot read your code from an image.

Here is a list of some issues I addressed and solved creating direct shape elements from quite complex OBJ source files:

http://thebuildingcoder.typepad.com/blog/2015/02/from-hack-to-app-obj-mesh-import-to-directshape.html

Cheers,

Jeremy

Re: Broken Mesh with TessellatedShapeBuilder

Anonymous — Thu, 25 Jan 2018 10:48:43 GMT

Hi,

Here is the source code:

(ppm) => {
rg.TessellatedShapeBuilder builder = new rg.TessellatedShapeBuilder();
builder.OpenConnectedFaceSet(true);
builder.Target = rg.TessellatedShapeBuilderTarget.Mesh;
builder.Fallback = rg.TessellatedShapeBuilderFallback.Salvage;
List<rg.XYZ> allVerts = ppm.Vertices.Select((pt) => ptConv.FromPipe<rg.XYZ, ppg.Vec>(pt)).ToList();
foreach (var face in ppm.Faces)
{
List<rg.XYZ> faceVerts = new List<rg.XYZ>();
foreach(ulong vertIndex in face)
{
faceVerts.Add(allVerts[(int)vertIndex]);
}
rg.TessellatedFace tface = new rg.TessellatedFace(faceVerts, rg.ElementId.InvalidElementId);
//if (!builder.DoesFaceHaveEnoughLoopsAndVertices(tface)) { continue; }
builder.AddFace(tface);
}
builder.CloseConnectedFaceSet();
builder.Build();
rg.TessellatedShapeBuilderResult result = builder.GetBuildResult();
List<rg.GeometryObject> geoms = result.GetGeometricalObjects().ToList();
return (rg.Mesh)geoms.FirstOrDefault();
}

I saw that article before and the airplane seems to be the closest match, which is caused by smoothing groups, but I don't have any smoothing groups.

Is there any other way to debug this and find out what exactly is going wrong with DirectShape ?!

Thanks !

Re: Broken Mesh with TessellatedShapeBuilder

Anonymous — Thu, 25 Jan 2018 11:04:58 GMT

I was able to export simpler meshes (spheres and cubes) and they work just fine. So that eliminates the face normal issue. Its only happening with complex shapes.