Stochastic flakes too large?

[MANUEL_MOUSIOL]

I am working on a car shader with stochastic flake material, but having the problem that the flakes seem very large to me although I have them already set at minimum (with mm units for the file settings).
I am also having trouble getting the flakes to only spread around the brightest lighted areas on the car.
Here is the light setup with a normal glossy reflective car material:

and here are just the flakes:

I put in a fallof fresnel map into the reflection map, set at 2.5 IOR.
BTW, this is a crop of a 6000x5000px rendering showing the whole car.
What I am looking for a is a nice subtle flakes effect that doesnt look like noise (the the client definitely doesnt want) but that subtle nice car paint flake shader.

Any help? I am clueless of what I am doing wrong.

[MANUEL_MOUSIOL]

check out these test results:



btw, the normal flakes material works normally as expected:

[MANUEL_MOUSIOL]

ok, I always used "real zoom" in the RT to look at details cause I thouht...well, it was like vray camera zoom. doesnt seem to be. cause all the results I got were like this:

but using actual vray camera zoom to do a crop (somehow 3dsmax didnt let me crop) I got these results:

which is much closer to what I am trying to achieve. still would like the flakes to be smaller, but cant get them to be.
getting the same results in RT with the camera zoom


still not 100% content with the result, but I found one error at last

[asen.atanasov]

Hi,

"flakes scale" parameters does not represent the size of the flakes, but is the scaling of the whole texture space. You must use the triplanar mapping with care and set "flakes scale" to sufficiently small value (0.01, 0.001..) depending on the scale of the object and increase the "num flakes" accordingly. You can find the exact relation here https://docs.chaosgroup.com/display/...asticFlakesMtl.

So the way to achieve smaller looking flakes is to increase their number, and you can also play with the "blur angle" parameter. Also I would suggest GGX BRDF type.

Also usually people achieve better results more than one layers of stochastic flakes. Take a look at this tutorial https://www.youtube.com/watch?v=qpPQk5fNrho.

Best regards,
Asen

[MANUEL_MOUSIOL]

ok thanks. that helped. I will play around some more.

am I right that Vray RT is computing the flakes at the original resolution and the real zoom option cant display more details because of that?

Hi,

"flakes scale" parameters does not represent the size of the flakes, but is the scaling of the whole texture space. You must use the triplanar mapping with care and set "flakes scale" to sufficiently small value (0.01, 0.001..) depending on the scale of the object and increase the "num flakes" accordingly. You can find the exact relation here https://docs.chaosgroup.com/display/...asticFlakesMtl.

So the way to achieve smaller looking flakes is to increase their number, and you can also play with the "blur angle" parameter. Also I would suggest GGX BRDF type.

Also usually people achieve better results more than one layers of stochastic flakes. Take a look at this tutorial https://www.youtube.com/watch?v=qpPQk5fNrho.

Best regards,
Asen