I’m extremely new to Blender, and am coming from a very different background (software developer, peer-to-peer networking) than I assume most here. Nonetheless, I started working on a material library - or rather a material service - to allow anyone to upload/download Cycles materials. My rationale was that currently there seems to be a mess of material repositories all over, each trying to somehow encompass the entire 3D modelling ecosystem, getting over complicated and less than useful.
I figured that I have the knowledge to put the service part together, I can make it community driven and I can automate pretty much the entire workflow. For example, anyone could just dump a .blend file with a material in it and get automatic preview renders + a minimalist derived .blend file generated with all the junk thrown out.
Actually, my entire service is mostly ready, I just hit a very annoying limitation that I can’t for the life of me figure out. The goal of my service is to be simple: drop the .blend file, select the material, boom, done. The issue is that I have absolutely no idea how to figure out the correct physical scale that a material uses.
Most of the materials produced by various people on the internet seem to have a completely arbitrary scale (for example, the above Cherry uses a preview sphere with a diameter of 1.27 units and a scaling of 0.106, whaa?). Is this really the standard procedure in the Blender/Cycles community, to download a material and waste 5 minutes trying to correctly scale it to the local scene?
My ideal system would be able to say that “Hey, this material should be rendered on a 2cm preview sphere” or something like that. That would allow the creation of collections that are scaled correctly to one another (e.g. an architectural collection where a wooden flooring is proportional to a table cloth or a balcony railing).
How are people here handling materials? How are you fixing their scale or using them in different scenes? The material preview render seems to be a 2 BU diameter sphere. If the material looks good on that sphere, it will almost surely look bad on any live object. How are you handling this?
I’d really like my service to be able to automatically generate nice preview images like the above one (it was generated through my service), nicely tagged about the scaling (4cm above on the image). Would be awesome to have a high quality material library for Cycles that could compete with the Corona Material Library for example, but Blender/Cycles seems to be missing this essential feature of assigning a unit to a material to allow making a uniform set of materials that work well together.
Any infos on how I could make this would be more than welcome.