GGX - best way to recreate it for all metals, problems translating to Corona

[rampally]

Tarnished Gold uploaded to CML.

can not find iton CML ...........can to provided the link please???

[GestaltDesign]

Sorry, yep you will have to wait for CML to administer them.

[daniel.reutersward]

Here is a render of my attempt at copper, not 100% satisfied with the result.

I hope it is ok that I used Grants shaderball hehe..

The reference images showed several types of copper, some more pink and some more orange. So I went for a more orange type.

[Juraj]

Nice :- )

I kept his ball too btw, no reason to change it. It's the nicest ball I've seen to date so why even bother.
Seems like great HDRi you used there, mind say what is it ?

[rampally]

Sorry, yep you will have to wait for CML to administer them.

Ok

[rampally]

Here is a render of my attempt at copper, not 100% satisfied with the result.

I hope it is ok that I used Grants shaderball hehe..

The reference images showed several types of copper, some more pink and some more orange. So I went for a more orange type.

(not 100% satisfied with the result) That's why i jut REQUESTED for direct  implementation of GGX in corona
and also  as juraj said many gaming programs are implementing PBR/PBS (Physically Based Rendering/Shading) why Not we can  expect ggx in CORONA ???
as we all know how well corona is made ......believe me i am using it since one year not even one crash till TODAY...
HOWEVER .....IT WILL TAKE SOME TIME ....Ondra Karlík can Do it

[daniel.reutersward]

Nice :- )

I kept his ball too btw, no reason to change it. It's the nicest ball I've seen to date so why even bother.
Seems like great HDRi you used there, mind say what is it ?

Thanks! :) Yes his shaderball is great! Sure, I used "Chelsea Stairs" from hdrlabs.com, tried a few and found that it gave a pretty good result.

(not 100% satisfied with the result) That's why i jut REQUESTED for direct  implementation of GGX in corona
and also  as juraj said many gaming programs are implementing PBR/PBS (Physically Based Rendering/Shading) why Not we can  expect ggx in CORONA ???
as we all know how well corona is made ......believe me i am using it since one year not even one crash till TODAY...
HOWEVER .....IT WILL TAKE SOME TIME ....Ondra Karlík can Do it

I was asked to upload a render with a material created the way Grant explains in his tutorials, it was not my intention to say that the request was not useful or anything.
I agree that GGX would be great to have implemented in Corona.

[Juraj]

Thanks Daniel, I totally forget about HDRLabs existence. The way the one you chose shows the highlights completely rocks.

[agentdark45]

The materials being produced in this thread are amazing. That's probably the most realistic CG copper material I've ever seen!

[nehale]

Here is a render of my attempt at copper, not 100% satisfied with the result.

I hope it is ok that I used Grants shaderball hehe..

The reference images showed several types of copper, some more pink and some more orange. So I went for a more orange type.

do you mind also posting the shading network for this material, really amazing

[Juraj]

Very quick test of mine, Blackened steel.

Layering works fine. Although, slightly differently than VrayBlend, but I can't put my finger on how.

Some observations: Corona keeps really nice highlight energy in corner almost unnaffected by glossiness. This seems almost strange, but maybe more correct actually. This can be seen on page 1 too, on the lion,
which looks better in Corona even with single layer. So I can confirm this. Same curve and eye-balled glossiness behaves differently in Vray.

The glossy curve in Corona is so much more linear than in Vray that it's almost hard to produce 'rough' (low gloss number) surface haha. With Glossy parameter 1.0 in Vray, driving only with textures, I kept the material contribution
in Vray 0.2 to equal almost 0.8 in Corona. I sort of don't know how to convert these to even remotely match. Not bad, just different, and puts point that if the material matters, just build it straight up, don't convert stuff.

Anisotrophy is so different. Seems like what is by default in Vray (Z-Axis, 0 angle) equals to Corona 90 angle (no axis can be chosen), but it still behaves differently. Can't stay bad or better, just, different, so I couldn't manage to match it well.

Overall, I think I am satisfied and can't wait for more advanced BRDF like GGX !

[daniel.reutersward]

Thanks Daniel, I totally forget about HDRLabs existence. The way the one you chose shows the highlights completely rocks.

Thanks! Yes they have som nice HDRI´s there!

The materials being produced in this thread are amazing. That's probably the most realistic CG copper material I've ever seen!

Thank you!!

do you mind also posting the shading network for this material, really amazing

Sure, I´ve attached a screenshot of the material in this post.

Very quick test of mine, Blackened steel.

Layering works fine. Although, slightly differently than VrayBlend, but I can't put my finger on how.

Some observations: Corona keeps really nice highlight energy in corner almost unnaffected by glossiness. This seems almost strange, but maybe more correct actually. This can be seen on page 1 too, on the lion,
which looks better in Corona even with single layer. So I can confirm this. Same curve and eye-balled glossiness behaves differently in Vray.

The glossy curve in Corona is so much more linear than in Vray that it's almost hard to produce 'rough' (low gloss number) surface haha. With Glossy parameter 1.0 in Vray, driving only with textures, I kept the material contribution
in Vray 0.2 to equal almost 0.8 in Corona. I sort of don't know how to convert these to even remotely match. Not bad, just different, and puts point that if the material matters, just build it straight up, don't convert stuff.

Anisotrophy is so different. Seems like what is by default in Vray (Z-Axis, 0 angle) equals to Corona 90 angle (no axis can be chosen), but it still behaves differently. Can't stay bad or better, just, different, so I couldn't manage to match it well.

Overall, I think I am satisfied and can't wait for more advanced BRDF like GGX !

Nice one! :) I´ve noticed too that there is some difference in both how the blending and the reflection glossiness behaves, I often use about half the value in refl. glossiness with Corona when creating a material in comparison to vray.

[maru]

Ok, I like doing things my way so here is a really CRAZY way of making a glossy material that has "various glossy values at the same time". Remember, I am doing this purely for fun. :)

Here is my process of thoughts: real metal has some given "characteristic" of surface because of micro-bumps on it. Why not recreate this as close to reality as possible by adding micro-bump map? But adding micro-noise as a bump map caused a lot of noise that didn't want to go away and really crazy things when it's size was very small (below 0,0001) so I simplified this by using micro-noise in glossiness slot. I don't like using layered materials with different glossiness because.... well... it is just few mixed layers with different glossinesses....

Why would this work?

Procedural noise, by using "threshold" parameters is capable of producing:
-uniform noise
-noise with larger or smaller "flat" areas
-noise with larger or smaller "slope" areas
And it has two colour parameters that will serve as minimum and maximum allowed glossiness.

My extremely quick tests are in the attachments. As you can see a proper setup will produce sharp+glossy reflections + all the other possible glossinesses between them. I hope it is understandable. :)

It is also vital to disable texture filtering or things get bad.

Maybe it would be possible to create such texmap for Corona that would be capable of producing infinitely small noise? :)

[Tanakov]

I think Im quite too low, to join in and have a good impact on this conversation. Yet I think that this is purely the moment to say

THIS WILL MAKE CORONA THAT STANDING OUT PRODUCT

[greysheep5]

Nice sharing of your findings and materials, very cool and much appreciated!

and on a sidenote, thanks for the tip with CML. coming from vray i didn´t know that such a site exists already before you guys talked about posting your materials there...

cheers,

christoph.