Add flight helmet model

[bghgary]

This is a high quality model from our tech artist @PatrickRyanMS. It is modeled after a real flight helmet and showcases what you can do with the core spec using PBR metallic roughness workflow.

[emackey]

This looks great!

Should we add a glTF-Binary flavor of this? Lately it seems like GLB is the most important flavor of glTF to support.

[bghgary]

I didn't do this because of size. This asset is over 50MB and is by far the largest asset in the repo. Each flavor multiplies against this base size. There are also plenty of tools now that convert from glTF to GLB. Thoughts?

[emackey]

Hmm, OK. SciFiHelmet also lacks a binary version, I guess we can have some models without it.

[cx20]

I tried this model with gltf-test.

The point I thought of as issue is as follows.

• The goggles of minimal-glTF-Loader are opaque.
• The goggles of PlayCanvas are opaque.
• The goggles of x3dom are transparent, but the contents displayed are different from other libraries.

Please tell me if there are other display parts different from the assumed one. I will report the issue to each library later.

The following is the execution result for each library. Khronos glTF Loader is excluded because Too many texture error appeared and it could not be displayed.

[lexaknyazev]

@cx20 Please fix Cesium link, it shows DamagedHelmet.

[cx20]

@lexaknyazev Oops! I was linking to a different helmet. I fixed the link now.

[cx20]

I confirmed that the problem of goggles has been resolved by using the latest version library of PlayCanvas and x3dom.

Three.js	PlayCanvas	x3dom

[donmccurdy]

Looks outstanding!

By the way, this helmet model contains a TEXCOORD_1 attribute that appears to be unused.

[bghgary]

By the way, this helmet model contains a TEXCOORD_1 attribute that appears to be unused.

Yeah, I noticed this earlier too. I'm not sure where it's coming from since the source asset doesn't have it. I'll find out.

[bghgary]

Should be fixed with #159

[andrewvarga]

Would it be possible to use the same environment to see a more consistent comparison between engines?

[cx20]

@andrewvarga If you would like to compare glTF models, I think that @vorg's pbr-compare will be helpful than my gltf-test.