Preview image from geometry

[lando.schumpich]

Hi,

I want to draw preview images for geometry in memory, to display in some Eto UI of mine.
One method I tried - I need that anyway for export- is composing a File3dm instance in memory with my objects and using File3dm.GetPreviewImage() which sadly always returns null.

I found this thread which could work for my purposes but is in c++ which I’m not fluent in.

Create preview images of geometry

Hi i want to create preview images of geometry which is not yet in the document. For this i tried to use the code below but i do not see the brep i have drawn with DrawShadedBrep, only those who are in the document. So is there a way do make preview images like this, but for geometry which was not yet added to the document? CRhinoView* view = RhinoApp().ActiveView(); CRhinoDisplayPipeline* dp = view->ActiveViewport().DisplayPipeline(); const CDisplayPipelineAttributes* pDA = CRhinoD…

Is there a similar method or overload in Rhinocommon?

Thanks for any help or suggestions.

[dale (Dale Fugier)]

composing a File3dm instance in memory with my objects and using File3dm.GetPreviewImage() which sadly always returns null .

If you create your own File3dm object, you’ll need to add your own preview image using File3dm.SetPreviewImage.

That said, would a view capture be sufficient?

SampleCsViewCapture.cs

– Dale

[lando.schumpich]

Thanks for the answer dale!

I experimented with view capture for quite some time today, but I really don’t like it from a UX point of view.

Maybe I am missing something, I need to be able to do the following things with the viewcapture:

• Create a RhinoView in memory
• Zoom to my virtual geometry
• Capture the view
• Don’t have any of those steps visual to the user

The problem is the zooming part. Even with RedrawEnabled = false i get visual feedback in the Rhino viewports.

Here is a preview of what I’m working on and what functionality I need, my plugIn is the Panel docked on the left side:

I can cache the images on the form after first creating them (which is why there is no jumping after selecting the objects again in the treegrid), but I still need a nice non-invasive way of generating those images

[dale (Dale Fugier)]

Hi @lando.schumpich,

Are you trying to create previews of instance definitions? If so, have you see InstanceDefinition.CreatePreviewImage?

– Dale

[lando.schumpich]

Hi @dale,

Yes thats what I’m doing, The CreatePreviewImage code does not allow for sub-instance highlighting, which is what i want to achieve:

I think i could get there with PushViewProjection and PopViewProjection, do you know of a comprehensive example how to use them? (The example code of PopViewProjection never actually calls that function)

[dale (Dale Fugier)]

Hi @lando.schumpich,

The code behind InstanceDefinition.CreatePreviewImage does allow for the highlighting of a single instance definition object. It’s just not exposed in any SDK. I’ve added a YouTrack item to provide this.

https://mcneel.myjetbrains.com/youtrack/issue/RH-55738

– Dale

[lando.schumpich]

Perfect thanks dale!