How to create lightest possible LOD4

[DevTest]

Hello, I have build 13k triangle furniture set that i will be placing in my home. All works fine except I cannot get LOD4 low enough. Auto generating allows me only 670tris , no lower for some reason. Then I created simple LOD4 mesh so that:

- main LOD and LOD4 have exact same number of materials used;

- materials appear in exact same order in both (sorted alphabetically, checked collada, yes - they really appear in same order);

- faces in LOD4 model are not tiny, they make up whole bounding box of high poly LOD model.

 

Now, when I try to upload it as LOD4 - i get this error which has been circulating over and over in this forum: "Material of model is not a subset of reference model".

So how can i make smallest possible LOD4 if autogenerating stucks at 670 and this custom LOD4 approach doesnt work?

Thanks in advance

[Drongle McMahon]

The order doesn't matter any more because the uploader now sorts the materials by name. You don't have enough triangles to run into the secret material problem (only happens at >21844 tris/material). So my guess is that you might not have triangles assigned to each of the materials at each LOD. The thing that matters in the collada file is the name of the "material" attribute inside the <polylist...> (or <polygons...> or <triangles...>) tags. There must be the same number of these tags inside the <geometry> tags of each object, and they must have the same "material" attribute values. It is not sufficient to have the materials listed in the materials section of the collada if they are not actually assigned to some triangles.

If you have used more than eight materials in one object, the uploader now deals with that by splitting it into multiple objects each with 8 or less materials. I haven't seen an example, but it is possible that this splitting may not be done in a compatible way in each of the LOD files. If that's the problem, and you really have to have so many materials, then you would be advised to split the models yourself rather than leaving it to the uploader, so you can make sure the split objects have the same materials at each LOD . A better preferable solution would be to simplify the texturing so that you don't need more than eight materials.

[arton Rotaru]

Another possibility could be that, if you have multiple mesh objects in your dae file, and the lower LOD mesh names doesn't match the ordering (see the recently introduced naming convention for LODs), the importer will mix up the LODs, and the material assignments won't match with their corresponding hi LOD parts.

[DevTest]

Thank you so much guys, it turned out I was too tired and in my LOD1 mesh there was a material not used with any triangles. That caused the problem. Now all works. Thanks