Hi,

I've noticed that very often there are problems with the normals smoothing map that comes from Moi when exporting to LWO and rendering in modo. It's not included in the picture below, but when using OBJ instead of LWO normals are fine. I would use OBJ instead, but I've also noticed that with OBJ there are more chances of having holes and flipped faces in the geo than using LWO, which causes more extra work fixing things afterwards.
I've also included an example of an IGES file imported in modo and rendered as it is.

Is there anything I'm missing and that I should do or shouldn't do to avoid this problem?

Thanks!

Hi Jacobo - there are different possible normals for LWO format, either Modo type or LightWave type - have you possibly switched the option for that to LightWave?

Check in MoI under Options > Import/Export > LWO options > "Vertex normals style" - make sure it is set to "Vertex normals style: Modo".


Other than that, make sure you are "item mode" if you are doing any transforms on the imported object - I think if you're not in item mode and transform just vertices for example you can end up with the vertex normals staying in their initial position and getting out of sync with the geometry.


- Michael

Hi Michael,

Thanks for your fast response. I made sure that Vertex Normals Style was set to 'modo', and I also haven't modified the object from its original position (not even in item mode). Just open and render. I've actually tried Lightwave mode as well just to see what happens, and it came out all black.
I've attached the object if it helps.

Thanks!

Hi Jacobo - I don't have a recent version of Modo over here so I won't be able to test it myself, but hopefully someone who uses MoI and Modo with each other regularly will be able to give it a test and give you some pointers.

Usually you should be able to just export out from MoI, then import into Modo and render though...

The materials that MoI makes by default though do have double sided lighting turned on, is that possibly having some effect on your renders?

In your original screenshot, it almost looks like there is some kind of environment map set up there.

- Michael

Hi Jacobo - another thing to check is if you're possibly rendering using some render features that have scale sensitive options, like bias factors and what-not to avoid self-shadowing or things like that.

If you are rendering with render features that involve some scale sensitive parameters then check if the imported object's size is fairly different between the different examples you posted.

- Michael

Hi Michael,

Ok, I've found the problem, and it doesn't seem to be Moi related. I was using modo 601 instead of 501, and for some reason it caused that. 501 renders it perfectly fine. I don't know if it's a bug or they changed the way normal vertex maps are read. In any case, I'll submit a bug.

Thanks for looking into it!

Hi Jacobo, I'm glad you found out what the issue was! Hopefully it is a bug because LWO vertex normals are already complex enough as it is.

Modo was the first program that used vertex normals out of LWO format but unfortunately they decided to use them in the opposite convention of the rest of the coordinates (something like vertex position coordinates in left hand coordinates and vertex normals in right hand coordinates).

Then later on LightWave 9.6 also supported reading vertex normals out of LWO but they expect a different orientation than Modo. Then for some unknown reason they decided to change it to some other direction in LightWave v 10.

Hopefully Modo is not going to now throw in a 4th different possible orientation for the normals, since the current situation of having 3 different possible orientations to use is confusing enough as it is.

- Michael

Modo 601 has not been released yet, so this must be a beta version? Jacobo's bug report will probably get it fixed before release. Maybe it would be worth passing on Michael's comments to the developers?

Hey Michale and Steve,

It sucks to hear about all the different ways to do that. I wonder why they decided to change it. Hopefully it's a bug and it will get fixed.
I've already submitted it and also asked if it was actually a bug or just a different way or reading those maps. I'll let you know how it turns out.

Thanks!

Hi Jacobo - someone else has written to me that Modo 601 seems to be using the LightWave v10 style orientation for vertex normals.

If you're using MoI v3 there are options for "Modo", "LightWave v9.6", and "LightWave v10" - if you set it to the LightWave v10 style does it then work ok for you in Modo 601.

- Michael

Hey Michael,

I've just read that on the modo beta forum as well. That's a good thing then. I'm not using v3 unfortunately since I've just started evaluating it so I downloaded v2 trial version, but it's good enough to know that it won't be a problem.

Thanks for letting me know!