By inheriting from GH_CustomPreviewComponent and overriding AppendRenderGeometry(), one is supposed to be able to add Grasshopper geometry to the render pipeline. This works in Rhino 7, but not Rhino 8 (SR24).
Please see PreviewTest.cs, which pushes preview items as follows:
public override void AppendRenderGeometry(GH_RenderArgs args)
{
if (_previewItems.Count > 0)
{
foreach (GH_CustomPreviewItem item in _previewItems)
{
item.PushToRenderPipeline(args);
}
}
}
In R7, the override appears to be called anytime the solution expires, and the pushed items appear in the viewport as expected:
In R8, the override appears to be called once per document load, and nothing appears in the viewport.
A similar issue is alluded to here and here. The latter mentions fixes forthcoming in SR8, but the only fix confirmed in the thread’s comments relates to a (different) issue with GrasshopperPlayer. Has anyone solved the original issue in R8? If AppendRenderGeometry no longer works, what is the recommended approach to participating in the render pipeline?