LODS / Material Switching

[Charlotte Bartlett]

I went off and made a dining chair - testing my new LOD knowledge to really push the boundaries of "details" versus "low prim" -  from the forum experts -  and spent a good 3 hours on retopo (ouch) for each LOD.

Anyway - super pleased with result.   I got a one prim dining chair (not yet scripted).   I am not going to lie - I can't just can't get the furniture  to work with imposters so I zero'd the final LOD - so this only had 3 LOD models.  Thats a challenge for another day for me as my fingers ache!

However, my next challenge!  Material Switching between LODS. It's refactoring the faces!

My materials are named the same, in the same order in each dae and the mesh items are also called the same in each dae - in each file I use the same name and each materials is 1, 2, 3.  There are joined in the exact same manner to upload with a couple of textures.      Screenshots attached - any ideas why this happens?  I was sure the new Firestorm put in a workaround for this issue....



 

Edited September 2, 2021 by Charlotte Bartlett
meant dae :)

[Candide LeMay]

It's not clear to me what you're trying to do and/or are asking about.

A mesh can have up to 8 materials. These materials are shared between all the LOD models. Let's say you have materials named A, B, C, D in your project. The high LOD model must use* all of them. Previously also all the lower LODs had to use* all the materials. What FS recently fixed was that the medium/low/lowest LODs can use* a subset of the materials from the high LOD instead. So for example the medium LOD could use* only materials B and C, the low LOD only material D etc.

*use = have at least one triangle with that material assigned

 

Note that each LOD model has its own UV mapping so it's possible to reuse the same material and show different things on different LODs, with each LOD being mapped to a different area of the UV space. This is also the preferred way for SL because it minimizes texture usage - it makes little sense to create a separate material that's only used for the low LOD - which based on your screenshot won't be very visible at 15+m.

Edited September 3, 2021 by Candide LeMay

[Charlotte Bartlett]

Ok not a Firestorm item and thank you I appreciate the time to reply - but the above I am aware of

All LODs are using same amount of materials, same names. in same order on dae export.  No LOD import has anything unique/changed bar the poly counts of course.

But per my screenshot when you switch between High to Medium to Low LOD the "faces" which said materials are applied to swap around so I get my cushion material applied to my wood frame etc.  The High LOD is fine.  I am not creating any separate materials per LOD - it's the same materials for ALL LODS.

I understand UV Maps in detail plus SL - but this particular face swapping is new to me

Edited September 3, 2021 by Charlotte Bartlett

[Chic Aeon]

36 minutes ago, Charlotte Bartlett said:

I went off and made a dining chair - testing my new LOD knowledge to really push the boundaries of "details" versus "low prim" -  from the forum experts -  and spent a good 3 hours on retopo (ouch) for each LOD.

Anyway - super pleased with result.   I got a one prim dining chair (not yet scripted).   I am not going to lie - I can't just can't get the furniture  to work with imposters so I zero'd the final LOD - so this only had 3 LOD models.  Thats a challenge for another day for me as my fingers ache!

However, my next challenge!  Material Switching between LODS. It's refactoring the faces!

My materials are named the same, in the same order in each dae and the mesh items are also called the same in each dae - in each file I use the same name and each materials is 1, 2, 3.  There are joined in the exact same manner to upload with a couple of textures.      Screenshots attached - any ideas why this happens?  I was sure the new Firestorm put in a workaround for this issue....



 

Well since  the majority of folks won't see the chair's lowest LOD (you can see that in the build panel) -- AND -- since those folks likely have low end computers and are USED to things breaking up for them -- and hence (if they are smart) turn down their draw distance ---- I personally think you are good.    I have tried several times to make my own LODs but mine are never any better than the uploader's. I box model so that might be part of it.   The imposter thing does work well for WINDOWS.   

 

I have only made ONE "product" this year and that was the casita which I really made for myself and decided to "share" :D. All the other things I have made for myself are going in an Advent calendar (big, big Advent calendar).   BUT I was just thinking today that I would be good to make a new version of filler buildings.   I haven't made new ones since SL14B???  Well  a long time ago anyway. And the imposter windows would work nicely in there.  For those BIG objects the lowest LOD usually doesn't matter that much (with my stuff anyway) and is basically ignored (sorry forgot the reasoning there).    So a project for September maybe.  

 

Also I don't think it was mentioned here but there IS a new uploader that is coming soon which is supposed to be an improvement. This either from INara's blog or the FS folks, I don't remember.   

AND if you ever do fabric then (if used carefully and CLEANED UP and errant vertices joined) the decimate modifier does a good job. You just have to watch carefully :D.   

[arton Rotaru]

Hard to tell. Obviously the material IDs got mixed up in the importer. I would try to re-assign the materials to the appropiate sets of polygons on the already joined meshes, and export again. Maybe the joining did something funky under the hood. I would also try to upload with the official viewer, just to rule out any issues the new Firestorm importer might have.

[Charlotte Bartlett]

Thanks Chic - I heard about that - to be honest with this chair commercially I could mirror high/med LOD from one then put in the Retopo on low and very low zero - it's "good enough" and you have to be I think a good 30M out for the LOD on LL Viewer and 50M out for Firestorm based on size to get the lowest on this model - (ignore screenshot above as that was just to demonstrate the faces issue between LODS.    That would come in (with fully scripted version) at 2 LI and that's good "enough" for this example I think...

Come on new uploader whoo hoo ha

 

[Charlotte Bartlett]

Just now, arton Rotaru said:

Hard to tell. Obviously the material IDs got mixed up in the importer. I would try to re-assign the materials to the appropiate sets of polygons on the already joined meshes, and export again. Maybe the joining did something funky under the hood. I would also try to upload with the official viewer, just to rule out any issues the new Firestorm importer might have.

Thanks arton!

1. LL and Firestorm - same behaviour (so it's me not them ha).
2. I went in to each and re-assigned - same issue.
3. Next I will try Blender versus C4D to see if a software issue.

[arton Rotaru]

6 minutes ago, Charlotte Bartlett said:

3. Next I will try Blender versus C4D to see if a software issue.

C4D. IIRC, I think there used to be an issue with C4D and multi materials with SL. But that is from 10 years ago. So don't quote me on that.

[Charlotte Bartlett]

Just now, arton Rotaru said:

C4D. IIRC, I think there used to be an issue with C4D and multi materials with SL. But that is from 10 years ago. So don't quote me on that.

HA you could be right - I can run a fbx out and see if I could do a different dae.

It's def C4D being a bad citizen.....   First difference as I started to do line by line compare on the .dae files.

 

[arton Rotaru]

Hm, that difference in count would to be expected between the high and med LOD I think. What is suspicious though, is that there are 6 materials listed, when you only have 3 on the model.

[Charlotte Bartlett]

This was an updated one as I split into 6 materials to see if that was the issue.

However I found the issue C4D R19 .dae file is problematic and causing the wrong behaviour and mixing out the .dae file incorrectly.

So I ran the export into fbx, imported into Blender, exported as .dae and IT WORKED....

Honestly it's like a marathon with LODS lol but at least we have now established 10 years later the more newer versions of C4D are also not able to support LODS properly for SL!

Thanks for all the debugging help as always!! ❤️

 

[arton Rotaru]

1 minute ago, Charlotte Bartlett said:

Honestly it's like a marathon with LODS lol but at least we have now established 10 years later the more newer versions of C4D are also not able to support LODS properly for SL!

Cool! I mean, not that C4D still has issues with that, but that I actually remembered it. I never used C4D myself, but a few buddies of mine did back in the day. I think there used to be a plugin for C4D to solve that problem. But don't quote me on that either.