Exporting 3D Models with RGBA

[adamrpatel49]

I'm currently visualizing a scalar field in VisIt and I plan to export the resulting graphics in a 3D format that can be used in a Three.js powered web application. My main goal is to preserve color and alpha information in the export, so I'm considering using either the .ply format or the .obj format with an associated .mtl file.

However, I've encountered a challenge when working with the VisIt GUI: I haven't found a way to export color information embedded in the .ply file using "Export Database" or "Save Window". Ideally, I would prefer to use the "Export Database" because it provides the option to export a 3D "movie" consisting of multiple frames.

As a workaround, I'm currently exporting my session in .ply format and then programmatically adding color headers in post:

property uchar red
property uchar green
property uchar blue

After adding these headers, I use Python or Blender to append RGB values to the vertices according to a 2D color mapping, or RGBA values from exported 3D density data. The second process is somewhat akin to manually extracting data from the .root file, and can be somewhat arduous for the less technical user.

I believe I could streamline this process using the VisIt API or some scripting, but I wanted to check if there's a way to achieve this directly through the GUI. Any recommendations or insights would be greatly appreciated!

[markcmiller86]

@adamrpatel49 Export database certainly makes sense. I wonder if WavefrontOBJ would be better format to try. Also, in VisIt there is a subtle difference between a "Save Window" operation and an "Export Database" operation..

That being said, I see MTL support in both the exporter and saver for WavefrontOBJ format. Have you tried that already?

[JustinPrivitera]

Echoing @markcmiller86, I think what you want to use is Export Database and use WavefrontOBJ. Then you can pick a color table that you want to use for your export.

[adamrpatel49]

Exporting OBJ w/ MTL (& the associated color table PNG) seemed to do the trick - thanks Mark, Justin!

[JustinPrivitera]

Glad to help!