VRayBlend Advanced blending mode

[trixian]

Hi.

I might have mentioned this in another topic earlier, but I'll specify it more in detail here.

Something I would like to be able to do, is emulate the fancy material blending used in a lot of games, and more specifically Unreal editor (UDK).
They have a special node they call Lerp, which AFAIK is actually a linear interpolate operation, where you pipe 2 or more materials into it, and it uses the normal and heightmap information in the materials to give the blending details based on the "shape" of the bump\height.
This is usually controlled/painted by using vertex colours to bring in each material, but in 3dsmax one should hopefully be able to use any colour map (including vertex colours).

I was thinking since vanilla 3dsmax has no real "agnostic math-nodes" available in the slate editor (not sure if Zookeeper has them), that some special-purpose node is needed for this result.
Maybe an option in the already stellar VRayBlendMaterial?
It should then hopefully be able to use either the internal normals bump node with a normal map and a height map piped in, or maybe the VRayNormals node could be updated to accommodate for the missing heightmap slot.

The actual maths and logic behind this operation eludes me as mathematics is black magic as far as I'm concerned, but the effect is easily seen in this link: clicketyclick

What are the chances of this appearing in my lifetime?

[instinct]

There is no blackmagic and you can reproduce that in vanilla max. lerp is a linear interpolation based on a weight. For 2 maps that would be the mix map in max. I have not read in all detail, but i don't see where you would need normals in that setup. All that i see on first glance is possible using standard maps i'd say.

Regards,
Thorsten

[trixian]

Well, if that is the case, I must be doing something wrong.
The blend map would need to take into account the height and normals of the blended materials to know which bumps and crevices to blend into each other.
I'm not sure if you just skimmed through the article or not, but my understanding is that this is not possible using the standard nodes available in vanilla 3dsmax.
Maybe these videos are better at showing the effect in question: ClickClack

One more
And another one

[trixian]

Oh, and here is a really good video showing off this feature with animation and other logic set up for automated effects: Video

[trixian]

Soooo....any thoughts on this from the devs? No comment even?
As an afterthought, this would have to be VRay-RT compatible as there would be no feedback from the max viewport.

[instinct]

I don't really have time to watch all of that in depth, but i still don't really see the problem. In most cases there are simple painted masks, no? If you need to take normals into account you can use VRaySamplerInfo (or for crevice/edge based mapping you can use VRayDirt as a mask). or world or object space based masking you can again use VRaySamplerInfo. In addition you can also use the falloff map in various modes to do position or angle based masking.

Regards,
Thorsten

[trixian]

You're talking of the VRaySamplerInfoTex?
I have no idea of how to use it, let alone how to "blend" it together with other nodes to get the desired vector/normal based blending which respects the materials "heights" as well. As for VRayDirt.....does it even react to normal maps and such?

[trixian]

Vlado...or other Chaos girls & boys, any thoughts on this?

[trixian]

Why is it that shader/material requests seem to get ignored or glossed over here? Its not like I'm whining on about wanting a bunch of presets for materials that are simple to manually create/reuse. This is more aimed at making Vray more powerfull enabling functionality not available to us otherwise. Does everyone think this requests stinks, or have people not actually grasped what I'm asking for? I'm pretty sure this would make most peoples lives even easier, and work slightly more fun.

[vlado]

They are not ignored; I simply could not understand exactly what you need and why you can't make it using the existing tools. Having a VRayBumpMtl material to make an edge for the transition between the two materials would certainly make it easier though.

Best regards,
Vlado

[vlado]

On second thoughts, what you need is a material (not necessarily the VRayBlendMtl material, it's not made for that) that blends between two other materials based on a mask, and at the same time uses this mask as a bump map, is that correct?

Best regards,
Vlado

[trixian]

Not exactly. The effect is like physically placing two objects with materials that have a predefined displacement amount of say 1 cm, so each object protrudes into the other in crevices first as you blend the displacement amount from 0 to 1, and completely covers the other as the "blending value" increases. In the examples above, the blending is done through RGB vertex colours for realtime purposes, but in our case could use bitmaps etc. as well. I know watching a video is irritating when all one wants is a quick overview as text, but these were the best I could find.
Because if my lack of understanding the actual maths behind this shader, I have trouble describing it in a useful way other than these moronic ramblings. All I know is what the effect is when it works, and I'm 90% sure this is impossible to do in 3dsmax as it stands without a new node, or without modifying the VRayBlendMaterial to read in these "heights" and normals when blending through a mask. In addition getting this to display in realtime as one paints, will require VRayRT compatibility.

The first link describes this process in a slightly confusing way, but the other video examples show the effect a lot better, where you can see where the different materials like sand protrude up in between the tiles when only slightly blended, and following the tiles normal map when blended more, before they cover the tiles. The video showing the animated shader system is the least descriptive, but in my opinion the example that really shines above the rest as it is beautifully executed.

[instinct]

But that would simply be a mask with a threshold for the "edge" and then paint the mask, no? I am afraid i still don't really get it.

[vlado]

Well, I think I got it However to do that, you'd need a VRayBumpMtl material at the very least, or a separate shading node; there is no direct way to do it right now.

Best regards,
Vlado

[trixian]

Hence my wish