GeometryInstance preview

[Anonymous]

Hi,

I have a linked cad file. The cad file has many blocks. My objective is to get the preview image of that block. Same way we get GetPreviewImage of FamilySymbol.  Any ideas?

Thanks & Regards

Sanjay Pandey

[Mustafa.Salaheldin]

Can you please provide the sample CAD file because I guess I know the solution?

[Anonymous]

Dear Mustafa,

Here is the example file.

Thanks & Regards

Sanjay Pandey(BIM[Revit] Developer)

[Mustafa.Salaheldin]

I got something like this:

        public void PreviewLinkedCAD(Document doc)
        {
            IList<ImportInstance> importIntaces = new FilteredElementCollector(doc)
                .OfClass(typeof(ImportInstance))
                .Cast<ImportInstance>()
                .Where(i => i.IsLinked == true).ToList();

            foreach (ImportInstance ints in importIntaces)
            {
                if (ints.Category.Name.EndsWith(".dwg"))
                {
                    ElementId typeId = ints.GetTypeId();
                    CADLinkType cadLink = doc.GetElement(typeId) as CADLinkType;

                    frmMain frm = new frmMain();
                    frm.BackgroundImage = cadLink.GetPreviewImage(new System.Drawing.Size(128, 128));
                    frm.Show();
                }
            }
        }

The GetPreviewImage method will not work for what I'm trying to do. Sorry about that.

Here is an explanation:

Import Instances don’t have preview images in the Revit user interface either.

If you go to place a family instance, the preview image is displayed like this:

For a Import Symbol, the preview image square in the type selector remains blank:

This is why GetPreviewImage has nothing it can return. There is a workaround to achieve what you want anyway:

You could create a temporary view, temporarily hide everything except the import instance, and create a snapshot of that.