Hi.
Can we have translucency element added to the list of render elements? To control the amount of translucency in post production?
SInce vray aproach to translucency changed to thin walled SSS, it would be nice to have it separate and maybe add a vray 2 sided material element as well, for old scenes.
Tks!
I join brunonz. It would be very nice if there is a render element “VRayTranslucency” as in Corona “CESSENTIAL_Translucency”.
Would be nice.
You may be able to achieve something similar by putting your translucency map into a VrayExtraTex and combining that with light select passed in post.
Could you show me an example comp where that RE is used, and how?
Hello, Lele. Unfortunately, I can’t show it now because I’m far away from my work computer (I’m on vacation :)). But half a year ago, in one of the projects that I did in Corona, when post-processing the final image, I needed to adjust the strength and color of translucency in window blinds and on the leaves of houseplants, for which I used the CESSENTIAL_Translucency render element. It would be nice to have a similar render element for such purposes also in V-Ray for the VRay2SidedMtl material and for the VRayMtl material with “Thin-walled” and “Translucency>SSS”.
Extremely useful for when the client says, “Looks great, but I want the levers to glow more from back lighting.” With the element you wouldn’t have to re-render, but could make a simple comp tweak instead.
That needs no specific translucency RE, it’s a simple materialselect RE with us, or through an LPE if one wanted the finest of controls.
My question was precisely to figure out how on earth could one post-change translucency (f.e., the color of either side, or the fraction) and that’s not on the cards, as i assumed.
We’ll see what -if anything- could be done about it, but the shading pipelines between the two products couldn’t be more different, so don’t assume it’s a possibility for us in the same way it is for Corona.
Not only for post production a translucency/thin walled could be useful. It can be used to check which materials have or check which is working. Sometimes i have to dig deep onto materials to see if translucency is working.
On vray, to have a similar element, i set some vray lights with include only vegetation objects. But the result is not 100%, but is a workaround.
Maybe Corona and Vray has different ways of calculations, but i believe there´s must some way to make it work.
Appreciate all the info.
Hello Lele,
thanks very much for your contributions regarding the translucency/thiin walled render element​.
I am not successful in build up a proper LPE formula.
Could you please post here, how such a LPE formula should look like ?
Thank you very much
Kind regards
Sure, here:
to select all the SSS events in the scene
C<TD>.+L
to select the SSS contribution just from the material named “Material 1”
C<TD>.'mMaterial #1'+L
Notice the LPE is parsed at least for some errors, and the log may contain clues as to what isn’t working.
Hello Lele,
Thank you for the support and the great input.
Kind regards
algato
Hello Lele,
unfortunately this formula does not capture the content of thin walled translucency sss​ (tree leaves illuminated from behind).
It is not about the classic sss like wax or marble block.
Is there a special formula for thin walled translucency sss?
Kind regards
algato
You are very right, it only supports normal SSS, the second “thin-walled” is turned on, the LPE comes out as black.
I’ll raise it with the devs, see if it’s fixable at all.
Thanks for your effort
Kind regards
algato
It seems that when thin-walled is activated, the SSS ray is stored in the diffuse result (it does make some amount of sense. regardless, it’s this way.).
Assuming the shader is called “TWSSS”, this expression ought to capture its direct contribution:
C<RD'mTWSSS'>L
With another LPE you can also extract all the indirect contribution of the shader, using this expression:
C<RD'mTWSSS'>.L
Should you wish to have all the contribution of the shader, then this would work:
C<RD'mTWSSS'>.*
Thanks, as usual with LPEs, go to the most excellent Dian.
Hello Lele,
thank you for your support.
C<RD’mTWSSS’>.L works fantastically, but currently with the clear restriction that the formula refers to a single shader.
The problem is, a typical scener, has several types of trees, bushes and flowers. That is a long list of shaders using tw-sss, for each of which one would have to build a separate LPE.
Is there a way to write the formula globally?​
or, if it is not possible to use the LPE globally, to write several shader names in the formula.
Kind regards
algato
Yes, of course you can use it globally, simply by removing the material selection, however that won’t work as the path is diffuse (so it will contain also all the other diffuse contributions from all the rest of the shaders.).
You *will* need a material select or an LPE per shader, or geometry, to be able to split the contributions.
It’s all quite easy to script, and the docs and LPE builder offer maxscript samples.
Otherwise, as the RE samples show, you can easily chain material or object names within the same LPE.
f.e.: C<RD['mMaterial #1''mMaterial #2']>L
Notice you may need further masks to be able to split them in post.
no body likes coding and writing stuff like that
a render element that calculates translucency throughout the scene would be a very important addition
i have attached an example of this beautiful element from corona
when used with a screen blending mode for example you can control how much translucent the foliage looks for example
you could also color correct at as you like
use a material select.
i will have to select every material in scene, sometimes there are around hundered ones, that will take forever
