[Pietro Spampatti]

It will be really nice and usefull to really hunderstand the material settings if the A-team will share scene like this one





Tom can you do it?

Thanks

P.

[BEM]

Or a little tutorial !!!!!

BEM

[Mihai]

Well, first do you know what a weightmap is, and how you use it in the material editor?

[rivoli]

first do you know what a weightmap is

what is that mihai? a tricky question?

[Mihai]

no it's a normal one

Sorry if it sounded strange, but just want to know where one needs to start.

I'll write it as short as I can, if something still isn't clear post your question


Like the caption in the glass image says, use a weightmap (greyscal RGB image) to blend to bsdf layers. You need two versions, one being the inverted version of the first one. A weightmap controls the influence of a bsdf layer. If you understand this concept then lots of things should fall into place.

About the leaf, there is a detailed post about it in the Maxwell forum, just search for clipmaps and look at the most recent posts.

[rivoli]

no it's a normal one

About the leaf, there is a detailed post about it in the Maxwell forum, just search for clipmaps and look at the most recent posts.

here's another one about blendig glasses using weightmaps you may find useful:

http://www.maxwellrender.com/forum/view ... hp?t=11317

[Pietro Spampatti]

here's another one about blendig glasses using weightmaps you may find useful:

http://www.maxwellrender.com/forum/view ... hp?t=11317

Thanks rivoli

P.

[rivoli]

figurati, piacere mio.

[rivoli]

Each layer needs a weight map? If so it seems like extra work for no reason. It should work like PS layer masks.

it maybe will at sme point, at leas this is what one may guess reading one of mike's post:
We also have a layered-shader implementation known as weightmapping, which will evolve into a traditional stacked-layer shading system.

[Mihai]

Adam, you're right, with the tinted glass example only one weightmap is needed. Sorry I got it mixed up with another method for making 'fake' clipmaps.

[rivoli]

Adam, you're right, with the tinted glass example only one weightmap is needed.

really? i tried them both (1 mapped weightmap and 2 mapped weight maps), and the tinted glass with 2 inverse maps looked better, at least in the mat preview.

[tom]

Use 2 weightmaps inverted

[Mihai]

hmm.....have to check that, but the weighting should be normalized internally. Or it could be that if you're just using 1 map, at the transition area, the material without the inversed map has too much influence. If both have maps then in the transition area it will look nicer, a 50-50 influence. But using two maps is not necessary.

[rivoli]

Or it could be that if you're just using 1 map, at the transition area, the material without the inversed map has too much influence.

well, that's what i thought. if the unmapped one is set on 100 the total amount will go, following a gradient, from 100 to 200 (?) where the map goes totally white. if set on 50 it'll go from 100 to 50 (where black). in both cases, and what's in the middle, it doesn't seem correct.

[tom]

How do we do normalization in weight values:

Example 1: 50, 50 OR 7,7 OR 123,123 ... means 50% , 50%
Example 2: 50, 150 OR 8, 24 OR 42, 126 ... means %25, %75

Mapped Weight is the same calculation per pixel, so we need to use
complementary maps for blending the layers equally. A basic black-to-white
gradient will require the inverted one on the other layer to participate equally.
If you only use 1 gradient map and the other one at a constant value 5.
The equation will be like this:

Layer 1: 0,0,0,0,1,2,3,4,5,6,7,8,8,8,8,8 (basic representation of pixel intensities)
Layer 2: 5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5 (constant weight value)
Result: 0 and 5 , 0 and 5 .... and so on... then the value 8 will be normalized down, due to 8+5=13.

The correct mapping for this purpose should be:
Layer 1: 0,0,0,0,1,2,3,4,5,6,7,8,8,8,8,8 (basic representation of pixel intensities)
Layer 2: 8,8,8,8,7,6,5,4,3,2,1,0,0,0,0,0 (basic representation of pixel intensities)
Result: 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8