Emulating Smoke in Glb
Emulating Smoke in Glb
9 Replies
Emulating Smoke in Glb Export. Needs further exploration but I think it's on the right track
(only previewed, haven't tested reimporting)
Notes (only looked at smoke here, haven't explored the others)
See video (ignore the first 15 seconds since that's how long it took me to figure out the gamebar thing)
OTX Stripped Test Changes
Smoke:
Alpha Blend
Emmissive from 0 to .5
Render Backfaces ON to OFF
SoftHighligheter
Color Luminance min raised to .5
Alpha Blend
Emmissive to .1
NOTED:
Adjusting visibility creates somewheat of a softer look with the smoke,
Alpha blend makes "puffier"
Emmission seems to make a bit brighter.
Adjusting Transparency affects
Needs tuning
The "Add" mode there is a babylon/threejs thing - it's not a gltf thing. we'd need to define an extension and get babylon, threejs etc to agree to use it
GitHub
How to handle additive transparency · Issue #1 · icosa-mirror/Unity...
The lack of support for additive blending has been discussed on the main glTF repo: KhronosGroup/glTF#1189 and in the broader context of blending modes here: KhronosGroup/glTF#1302 Unreal's glT...
Hmm, well, I'll see if I can export it successfully and if it gets read or not. At least an intermediate workaround if it actually functions
I read that thread already, but good reference
Hmm. Unfortunate. Was almost excited there for a moment
Interestingly, looks half-decent in blender. At least when in 3d "preview" mode (not so great in rendered mode). Unfortunately not so much when rotated, where the 2d slices can be clearly seen. Possibly removing backfaces may have had something to do with that part of things. In the AR viewer, I get the black border issue unless I tweak the materials, and then it loses the radiance it has. Of course, I don't know if they're using the full options set or not. Decent chance that they have emmissive turned off for performance reasons, since its a phone app
yes - but is it using additive transparency or is it just using alpha blending?
It has transparency controls, but its not showing the normal. I've got a setup where I generated the maps for everything that could, was thinking about looking at that next. That version has some other issues, but I'll see if I can find an intermediate stage before I started thinking about animations (which was a bad idea, lol)
I need to experiment with it more, to understand what it does and doesn't do. Just got started on that before I packed up and had to reset my entire perspective
Right now, the biggest issue appears to be that it displays the background (the black square) in the viewer. It's also slightly visible in 3d viewer,
and when I re-import the exported file from the sandbox, or the original export.. they both work in game. Intersecting the smoke with the controller reveals the square's outline, when in this mode. Can tone that down from some angles, but definitely not the desired effect.
What app are you hoping to display gltf's in? This is somethine we probably address on a case by case basis. Like I said - for Blender, Godot etc I'll have an import plugin.
And once we make a start on defining the additive blend mode extension - we'll also define what the fallback is for apps that don't support the extension.
(maybe something using emission)
so - it's three prong thing:
1. custom importers
2. gltf extension
3. A last resort fallback
Sounds like you're fretting about (3) before I've done 1 or 2
Unless I'm misunderstanding what you're trying to do?
Yes, it seems that way. You weren't misunderstanding, I was hoping that there was a more direct method possible.
When the first two steps are done, then will deal with getting whichever resource to adopt it, or maybe make my own if I feel particularly ambitious.
Is it correct that this will be a fairly involved process to get a functioning importer that can manage these things?