Should tMR allow .blend files?

[Peardian]

Here are my thoughts on this.

.dae does not support normals.

I'm not sure where you got this idea, but the DAE format explicitly supports normals. Search for semantic="NORMAL" in the specification doc.

.obj doesn't support rigging or vertex colours and requires an additional .mtl file.

Correct, OBJ is an old and limited format. It is certainly not ideal. However, the format is stable and still commonly supported. Bones and vertex colors can't always be ripped, such as with screenrips, and many models don't have them at all. In those cases, OBJ is perfectly fine.

Neither handles more than one UV map very well, if at all.

It is true, OBJ does not support multiple UVs at all. However, DAE explicitly supports multiple UVs just fine. The problem with multiple UVs is that they can be difficult to work with. This is why we ask people to include a version that splits the UVs apart onto separate mesh copies, for cases where importing multiple UVs is not possible. In cases where the UVs are split, an OBJ is perfectly fine because each mesh would have just one UV anyway.

.fbx is opaque (unlike the other three) and so cannot have minor issues fixed by mods.

Correct, which is why it's only allowed as a bonus. Also, the format is being updated over time, which means newer programs can't open old FBX files and older programs can't open new ones. These reasons are why it is unsuitable for a primary required format. (Just clarifying for others who read this.)

.smd has been considered outdated by its main audience for several years.

I have no strong opinion on SMD. I've personally never used it.

.blend, while proprietary, is free and open source. There is a high likelihood that users downloading models from tMR are already planning to bring them into Blender. Giving them a .blend to begin with will decrease initial friction by a lot.

Given the above, I would like to suggest that .blend be made a generally legal secondary format. It can't be a primary format because it still is proprietary (I presume), but it would allow the proper retaining of so many more model properties than the current formats, and is likely to have a large "market share" of users who can just open it up and not need to make their own materials.

The main issue with BLEND files is that they only work with Blender. Those files will be useless to anyone using 3DS Max, Maya, Cinema 4D, etc. However, it is true that Blender is freely available and widely used. I am not completely opposed to their inclusion, but the files are a lot more complex and more difficult to vet. BLEND files can not only have resources packed inside, but also custom layouts, scripts, and other things. If any of these things had a problem, we'd have to either spend extra time to fix the issue or remove the file entirely. That adds even more time to review each submission, not to mention potential issues with Blender version compatibility.

One situation that I very much want to avoid is people relying on Blender for handling everything difficult. The last thing I want is for someone to download a ZIP and the readme says "Animations are in the Blender file" or "Other UVs are in the Blender file" or "Vertex colors are in the Blender file" or "Bones are in the Blender file" or even "Textures are in the Blender file".

I agree that there is some value in being able to provide material setups for complex materials like those in Splatoon, even if it only works for Blender users. However, from what I have seen in other submissions, this same information can also be conveyed through images of the node setup and/or tutorial text. Personally, I think teaching users how to make the setup themselves is better than just giving the finished package. ("Give a man a fish..." and such.)

Again, I am not completely opposed to its inclusion. However, I worry that the potential convenience it can provide will be outweighed by the issues it can bring.

I will say that I wouldn't consider .blend files proprietary any more than I would .zip or .mp3.

It seems I have not been using the word correctly. Blender files are not, by definition, proprietary. However, I would still lump them in the same category as .MAX or .MAYA files because Blender is the only program that uses them to any degree.

Ironically FBX is proprietary and nonfree,

Huh, I didn't know that.

My hot take: allow any format (even .c4d or .max)

This would be a nightmare for reviewing. We're not going to blindly trust such files, so it would either create a bottleneck based on which staff has which program, or it would require all of us to shell out money and install a bunch of programs. Either that, or we'd end up deleting the ones we can't personally verify, which would be a lot of them. Regardless, it would just be a lot of extra hassle for very little benefit.

Then there's .glb and .gltf too, which absolutely would be good to have

We do allow GLTF as a bonus, but not ones with images packed inside. There is no reason to pack 10 MB worth of textures into a model file when those same textures are sitting in the zip. We don't allow GLB since they are opaque and usually have the textures packed inside anyway.

but the sad reality is that there is no (and _can_ be no) real true super all-encompassing format for any 3D stuff.

This is true, and that's why we prioritize the essential things (polygons, UVs, base texture, bones, etc.) over extra stuff (normals, animations, morphs, most vertex colors).