Max crash on fbx import with CoronaMultimap

[subpixelsk]

I am wondering if you guys can reproduce this . When I export an object with material with multimap plugged in to fbx, on import max crashes. This happens on max 2018 with Corona 4 and I tested this also on max 2017 and Corona 3

Thanks a lot

[subpixelsk]

A little update

I made some tests and crashes occur ONLY if the input node to multimap is one map (bitmap or color) instanced to all submaps (e.g. 3) . When I duplicate the original map and plug each one separately to multimap it won´t crash. Can you guys confirm this is a bug?

[subpixelsk]

also is it known behavior that after fbx import all nodes before multimap are missing? - so only multimap is there but no submaps

[PROH]

Hi. Made a little test with Corona 3,2, and I got no crashes at import. But of course the Corona Multimap wasn't exported to FBX, since this map-type isn't part of the "FBX standard" (at least for now).

This test also made me wonder: What exactly are you exporting and what are your expectations?
- Is it Corona materials or is is Standard materials with a Corona Multimap inserted?
- Do you expect to import Corona Materials?
- What version of Max are you using, and what version of FBX are you using?

As far as I know, the FBX format doesn't yet support Corona materials (or the other way around), meaning that all maps that are outside of the "Standard" definition will be ignored. Thats why it is common pratice to convert all materials into Standard materials before export - no matter if it is FBX, DAE, 3ds or OBJ (+ more) you're exporting to.

Hope it helps

[subpixelsk]

Hi PROH

thanks for your test. Did you try with the scenario I posted above? so only one map as submap but plugged into 3 nodes of multimap for example?

I am exporting Corona materials
I expect to import Corona materials if possible
I have max 2017,2018 and 2020 and fbx usually 2015 for 3D model marketplaces

On my side I can import fbx storing corona materials

[romullus]

I think crashing is not Corona related. Corona can't control how FBX is imported/exported. Try to change render engine to default scanline or Arnold and import offending FBX, if it still crash, then you have to report it to Autodesk, not to Chaos Czech.

[PROH]

Hi. Yes I tried to export a Corona material without Corona Multimap, a Corona material with Corona Multimap containg 1 bitmap in 1 slot, and a Corona material with a Corona Multimap containing 1 bitmap copied in 3 slots. I didn't get any crash on import, but I didn't get any coronamaterials nor multimaps neither. All I got was 3 standard materials - the first with the used bitmap, and the 2 others with an empty bitmaploader.

I tested this on 3dsMax2014 with Corona 3,2 and all Corona Multimaps were put into the diffuse slot.

I've never been able to get a Corona material via FBX import in any version (2014, 2016 and 2018). Would love to know what FBX version you are using to do that.

Best Regards

[subpixelsk]

So the common workflow for fbx export would be to convert all materials to standard without maps so users would need to create materials themselves from scratch?

[PROH]

No, Standard materials with maps. But only those that belongs to the Standard mtl. Depending on what program is used for import, you might find that some settings is lost to :(

I know that there's something going on with FBX and VRay materials, making it easier to exchange files between multiple programs. Maybe Corona could be/is part of that too? Afterall it's now owned by Chaos Group.

[rowmanns]

Hi,

Thanks for reporting this. I can reproduce the crash here and we will look into it.

Thanks,

Rowan

(Internal ID=366807395)

[PROH]

Hi. Just wanted to update my response. I've installed 3dsMax2020 and tried to export the same file as before to FBX with Corona mtl. And now I finally got it to work with Corona mtl. That is great! :)

The FBX version used was 2019.2, and I got no crash on import. The Corona multimaps imported fine, but unfortunately without any bitmaps.

Best Regards

[rowmanns]

Hi,

After some investigation we have discovered that this crash is caused by 3ds Max not Corona.

I have forwarded the bug report on to the Autodesk team.

Thanks,

Rowan