Octane exporting speed and possibile imporvements Tweet

[matej]

Hi!

I did some speed measurements of the Blender->Octane workflow, compared to Blender->Yafaray, on a 1.6mio verts scene:

Octane exporter takes 07:35 to export the geometry to .obj and fire up Octane, then Octane takes 03:20 to parse & voxelize and start rendering.
Yafaray exporter takes 02:20 to export the geometry to its .xml format and another 02:12 to import it and start rendering. If exporting is done directly to GUI (without the middle step of writing the .xml) it takes only 02:42 before Yafaray starts rendering the same scene.

My observations:

* Exporting to .obj and then importing it is a major bottleneck here. Also the .obj format is not very optimized in terms of structured data, ie. parsing and re-creating data from it takes longer than some better structured XML (that is my guessing here, and I might be wrong). Are there any plans of integrating geometry data into .ocs xml format, or even better - make a binary scene format that would contain everything Octane needs? In either way exporting should cut the unnecessary middle man - the .obj file.

* The 'legacy' .obj Blender exporter code that is incorporated into Octane exporter doesn't seem to be very optimized. If Octane exporter takes 3x more time to write down the same amount of data as opposed to Yafaray, then there's room for improvement. But if the code is optimized, that wold just enforce the necessity to change the geometry-holding file for a better structured one.

I'm not criticizing here, just making some points, because I would like to hear the opinion (and plans) of devlopers. As of now, the exporting step is a major slowdown in the overall Octane speedy workflow.

[Nostromo]

Point taken and we're aware of the situation.

Thanks
/M

[enricocerica]

Hi guys,

It seems that by disabling the Triangulate and HQ options in the advanced tab dramatically increases the performances during the export process. I made several tests and I got over 7x better performances without no visible impact on the result. Could you please check that point and post here any issue you may notice after disabling those options.

Thanks

[matej]

Yes, with triangulate and HQ disabled the above scene takes 03:19 to export, which is quite an improvement. It still takes 03:20 to import & voxelize

I'll make some additional tests about the impact of HQ

[brecht]

If I remember correctly, the HQ option in the OBJ exporter was added mostly for low poly game models, where you might create "ugly" geometry to keep the polycount down. As long as the mesh is relatively high poly I expect it to make little difference.

[matej]

Yes, I can confirm that. I tested it with a relatively lowpoly model with 2 levels of subsurf, and there was no noticeable difference in renderings with HQ and without. I also tested the same model without subsurf, and there was a slight difference in shading in some parts, but nothing noticeable and you wouldn't use such lowpoly model in production anyway. So no problem here.