[Mihai]

I guess the flakes are suspended at different angles inside the paint and so some will reflect more than others. But it's true for any view except extreme closeups the individual flakes become more of a homogenous effect and you could do it with a separate bsdf layer.

[chrisvconley]

Yeah, what I started before life interrupted me last night was to create what is essentially a noise map of flakes -- small sharp and various sized pixel areas that could be used in a BDSF to make super high reflective sparkles. The varying size and sharp edges is meant to mimic flakes at various angles.

Perhaps even using fresnel angle to control fall off of reflectivity based on angle...

Would this work, Mihai? (I know, I know, try it!!!)

[Kabe]

normal mapping for flakes?!? why? why even bump map it.. are flakes really raised up and such? huh I would figure just a seprate layer to control their reflection....

normal mapping is about reflection angle, not about displacement.
The flakes are little embedded metal particles in the paint.
Normal mapping is perfect for that.

Kabe

[LarsSon]

Base layer has solid color pink. Nd 8
Roughness, anisotropy and angle mapped with same "speckle" map.

Second varnish layer is light gray. Nd 3
Transmittance is very light orange.
Roughness 2

Both have weight 100

i'll try to make it better soon. Maybe not so candy next time.


-LarsSon

[3dtrialpractice]

normal mapping is about reflection angle, not about displacement.
The flakes are little embedded metal particles in the paint.
Normal mapping is perfect for that.

Kabe

ahh ha!.. ok I understand beter now.. so the red green blue of the normal map will act like a direction indicator for the flake... thanks.

LarsSon....

Thanks for the explination, useful to know that you mappe dyou anistropy and that your transmittence was a slight color too..

thanks ,
luke

[Hybaj]

Only with a normal map the glitter material would be just like a super randomly subdivided disco ball. The material is more sophisticated than this. I'll dissect a sparkle wrap later to see how the material really works

[superbad]

I needed a metallic paint material as well, but I took yet a different approach. Instead of using the noise as a texture map, I loaded it as a weightmap between two layers: one rough red layer, and the same noise map inverted on a silver layer for the flakes. The metal layer has a bit of roughness so that it doesn't act so much like a mirror picking up all the background reflections. Both layers have a coating to give a uniform smoothness to the surface.

I tried using an R2 file to control the falloff on the metal layer, but I ended up giving the metal layer a slightly lighter red than the paint layer in both reflectance slots. I think I need to play with this a bit- it doesn't look right to have that little bit of red noise in the white highlights. This is only SL12, so some of the white noise on the red will probably still go away.

There are a lot of ways to make this kind of material. I think this one works well on the vertical triangular face in that cutout in the lower left corner, but I'm not really happy with it elsewhere. But if you look at real photos of metallic paint, the "metallicness" is very hard to see unless it's a really exaggerated metal flake custom paint job. Typical OEM metallic finishes are very subtle.

[LarsSon]

Superbad: It looks like your paint material is missing varnish layer.
Basic paint is ...ok but it looks too flat for me.

I'd like to make material that feels right. (Red Paint)

Red paint have to look and feel like:

-There is only one colour (hey, that is Ferrari red!)
In this situation you can't use any texture maps.
It's just solid red colour.

-Oooh... it's so shiny and reflecting! (varnish layer)
We can't make too shiny or reflecting paint layer.
It'll loose strenght and deepness. So we have to do
another thin layer for reflections. It should be allmost transparent.

-It's shining so beautifully under the sun!
We need somekind of flake things to turn that paint alive,
to show wider colour range in part of our paint colour, but
still seeing this paint as basic red colour.

Just my toughts. Hope you understand what i ment.


-LarsSon

[jfrancis]

I heard they used to tag nuclear missiles with glitter paint in a clear epoxy as an unduplicatable ID.

They'd paint a patch and then photograph it under certain varied light angles.

Very hard to counterfeit: Even if you managed to duplicate the position of each flake, you'd never match the orientation of each flake.

[Kabe]

Only with a normal map the glitter material would be just like a super randomly subdivided disco ball. The material is more sophisticated than this.

Absolutely... However, normal maps are better ingredients than bump maps for this.
I'm quite aware that this is only a small piece of the solution


Kabe

[Tim Ellis]

Some useful info on using normal maps for metallic flakes.

http://www.ati.com/developer/shaderx/Sh ... Shader.pdf

Pearl metallic paint:-

http://www.mpi-sb.mpg.de/~karol/papers/EG01Paint.pdf

http://www.integra.jp/eng/papers/Revers ... paints.pdf

[Kabe]

Ouch... they think they need even 16-bit normal maps...

Great papers! Thanks!

Kabe

[LarsSon]

Thanks Tim. That was really good reading.

First i want to show some extreme sample.

In this version i have modeled everything.
-paint model
-clear coat model
-flake particles inside clear coat

Well, it doesn't look good, but it was fun to try.
Somehow half of particles are black? Material is allmost mirror.







Then i want to show some more realistic material.

This is allmost same as my test in first page.

---------------------------------------------------

Base layer: 100

-bsdf
-Solid color
-roughness 45
-bump 0.5 - flake.jpg
-coating
-thickness mapped - flake.jpg

Varnish layer: 50

-bsdf
-solid light grey
-transmittance - light orange





...and some exposure variations to see how shader works.

[Hybaj]

Very nice but a bit too reflective

[Leonardo]

Wow!! that's one of the best car paints that I have ever seen... you even got the orange peel

I take off my hat ... Where is the example file so we can all get enlighten with your genus?


I feel like rendering cars all of the sudden