Save Slider Animation as PGN with transparent background

Replies to This Discussion

Permalink Reply by David Rutten on September 13, 2010 at 9:28am

hi kVVV,

I don't know if Rhino can export viewport contents with alpha channel. But what you could do is run the animation twice, once with colours, once with only black geometry and a white background. You can then use that second pass and apply it as an alpha using some sort of pixel post-processing.

Pretty involved, but I don't see another way soon or indeed at all.

--
David Rutten
david@mcneel.com
Poprad, Slovakia

Permalink Reply by Igo Kommers Wender on September 13, 2010 at 9:32am

Thanks David. Yes, pretty involved, but it should work. I will try it.
Cheers
Rod

Permalink Reply by Evan C on February 4, 2013 at 9:30pm

I've found a relatively painless way to do this... green-screen technique

1. set viewport bg to green=255

2. run animation export.

3. photoshop define an action like this:

3a. open file

3b. right click bg layer, click layer from bg

3c. select color range (greens)

3d. delete

3e. save as

4. photoshop automate batch with that action.

that should give you all the sequential images w/ transparent background. 

of course, if you have a lot of green in your image, you'll need to pick a different color for replacement...

Permalink Reply by Nick on February 5, 2013 at 4:34pm

Using photoshop to automate and using David's "alpha channel" method might produce a better result? I'm thinking anti-alias edges here...

Permalink Reply by Hannes Löschke on February 6, 2013 at 4:35am

Rhino 5 can capture with transparent background. So this method is neccessary for Rhino 4 only.

Permalink Reply by Evan C on January 31, 2014 at 10:04am

Has anyone found a more elegant solution for this? It would still be nice to be able to automate generation of png files with a transparent background.

Permalink Reply by Hannes Löschke on January 31, 2014 at 11:15am

Currently there is no support for transparent background in viewport capture in RhinoCommon. Only ViewportCaptureToBitmap is exposed, which doesn't return transparent bitmaps. (see here)

For now you could script the ViewportCaptureToFile command.