Error: Material of Model Is Not A Subset Of Reference Model

[Naiman Broome]

Hi, I have been trying to upload a mesh , its a tree and its composed of 5 objects , a trunk , 2 fronds , fruit and details ...

 

The fruit and the two fronds use the same texture, I preferred to keep separate to be able to easy manipulate in 3dsmax without messing up model ...

when I upload alone I get 34 prims , when I did the first lod , I removed the detail model and added in its place a hidden triangle with the same material , then exported...

 

but when I try to import the lod I always get that error , any ideas of how to solve?

[Rya Nitely]

When this happens to me, I open the 3D program twice (I use Maya) - once with my main model and the other with ithe LOD model. I then compare using hypershade to frame each material making sure it's present in each model, and also checking the names. For me it often turns out be a naming issue - same texture but the naming is different. 

It also happens if I forget to link my object into one object. If the main item is one object then LOD model must be one object too, or if the main item is 2 objects unlinked then the LOD model must have the exact same textures (at least in naming) for each unlinked part.

[Naiman Broome]

e tried another way , I have picked my high res model cloned and started deleting polygons so to reduce polycount, I left for the unneeded parts just a triangle and hidden those inside the trunk , then turned to mesh and exported ...

now I can load and I do not get the error but I get anohter issue, wich is the mesh looks enlarged and the parts that I wanted to delete now looks like supersized polygon in the viewer ... If I try to load the lod model as a normal mesh it loads fine but if I load as a lod it looks deformed , stretched and with those huge polygons ...

 

I am starting to think this lod is utter broken ...

[Rya Nitely]

I t could be that the LOD Model is not the same height and width as your high res mesh. it will stretch to fit. Use triangles at the extremities so it's the same size. This is what I would try.

[Naiman Broome]

ah it has to retain same box shape?

[Rya Nitely]

closest you can get to same shape and size is important so that the change in LOD level isn't too obvious.

[Drongle McMahon]

First: From your description of the things you tried, I would guess your original detail model had more than 21844 triangles in one material. In that case, the uploader starts a new material without telling you. If this happens with your high LOD but not your lower LOD, because the latter has fewer triangles, then the two LODs no longer have the same number of materials, and you get the error message. There are other, more suble, problems that also happen as a result of the hidden meterial additions. The solution is to never use more than 21844 triangles in any material of a model. The is presumably what happened when you reduced the poly count.

Second: All lower LOD meshes, and the physics mesh if supplied, are always stretched and/or squeezed along x, y ans z azes, until they fit into the same bounding box as the corresponding "reference£ high LOD mesh. That explains why your hidden triangle expanded. To avoid this you have to include geometry that extends to the edges of the bounding box. (There are devious ways around this, including by manual editing of the collada file to include unreferenced geometry, but I won't elaborate as these exploit bugs that may get corrected).

ETA: if you want grizzly details, you can look in the jira at BUG-9015 and BUG-8987.

[LeEnfantTerrible]

 

@Drongle

 

THIS

- > In that case, the uploader starts a new material without telling you. If this happens with your high LOD but not your lower LOD, because the latter has fewer triangles, then the two LODs no longer have the same number of materials, and you get the error message <-

... just totally safed me. Thank you for explaining it so well, I never knew that the uploader starts a new material without giving notice if the count exceeds 21844tris. But this explains a lot of errors I had in the past that left me basically guessing for possible issues

Thanks a lot!