- This topic has 38 replies, 4 voices, and was last updated 6 months, 2 weeks ago by Eric.
October 27, 2020 at 4:18 am #5564Eric
This image shows an attempt at ‘first spots of rain’ using cubic mapping to get a topology effect, If I had a subtractive layer option it would work better, you can see the artifacts but they also look like streaky rain drops so thats fortunate in this case.
The diffuse texture is UV-mapped in this example, which is obviously a photoscan.
To make this effect work better, I would like to use 3D procedurals in a subtractive layer, weightmapped in a way that responds to the topology, maybe using cubic mapped gradients or some kind of directional procedural.October 27, 2020 at 6:11 am #5566yossi
that looks very good to me, however I must say that the cases you’re talking about are maybe 1% of typical work while what I asked for a few posts earlier is 99% of materials work 😉October 27, 2020 at 6:59 am #5567Jeremy Hill
We’re working on that, but have been preoccupied finishing up a round of performance improvements that go pretty deep. These were all rendered for the same amount of time:
Thanks for the examples Eric, of course they look great, but still trying to wrap my head around exactly (technically) what you’re showing. I just promoted the above 20.15 to the public downloads, and have to put together some press release stuff, then I’ll get into this material stuff with more focus.October 27, 2020 at 1:10 pm #5569Eric
Thats an epic speed-up, well done guys.
I can hardly wrap my head around these either, so long since I made them, seem’s straightforward until I try to explain it..
The main point is that the material system should allow for creativity beyond any expected use cases.October 27, 2020 at 6:48 pm #5571Eric
Can Bella 3D procedurals be stuck to geomtery to allow for deforming animated geometry? I hope this will be possible.
Aside from that, the main idea I was rambling about is that sometimes its useful to combine 2 or 3 mapping channels to mask something so that the effect hits only certain areas of the geomtery. If the material stack is flexibly designed and allows similar mixing ala Photoshop, then we can exploit that to work with the channels, very similar to how we use multiple channels in photoshop to isolate things.
Maybe you could design a simpler system whereby any weightmap slot can host 2 or 3 weightmaps (in a layer menu like photoshop), all with their own channel coords.
And just a reminder that weightmap strength controlled by viewing angle is essential for thin fabric, and many other things. Think sheer tights… ok stop.October 27, 2020 at 11:06 pm #5574Jeremy Hill
The only procedurals we have yet are 2D, so they exist in UV space and would indeed be “stuck” to geometry, if that’s what you mean (as opposed to a 3D world-space procedural).
We already natively support some of what you refer to with combining weight maps, by virtue of nodes having inputs & outputs. But I think you also want a sort of “map mixer” node, to create one map from multiple maps. And in that case, as currently, you would have control over the UV channel used, on a per-texture basis, on a per-instance basis (you can use different UV sets with a given texture, on different instances of a given mesh).October 28, 2020 at 12:14 am #5576Eric
When you get 3D proc, I hope there will be a way to make it stick to the geo? Not sure how that would work though because Procedurals are calc’d on the fly… hmm.
If you imagine 3 high contrast noise maps, flat mapped in 3 axes, the resulting output when the maps combine in 3D space will be either, white , black, dark grey, or light grey. This noise can be stuck to the geo, it’s crude but it works. I imagine it’s not that efficient either.
But I use the same idea to map dust onto a car tyre without it getting into the tyre grooves, there are so many uses for combined mapping coords.October 28, 2020 at 3:12 am #5578Jeremy Hill
Well when you are evaluating an impact, you ask a texture for the color at that point, whether it is a 3D texture in world space, or in object space, or a 2D texture in UV space. UV space obviously follows a surface as it is deformed, but for the other two, if the point is moving through space, then by definition it is going to get a different value. It sounds more like you want to bake a 3D texture into a UV-mapped 2D texture, and then deform.October 28, 2020 at 1:09 pm #5581Eric
Yes, but most of the time baking an actual UV-map is not an option, because of the geometry.
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