View Full Version : Glitter in skin shader ?

10-21-2013, 12:47 AM
Can anyone explain what I am doing wrong with the GI/skin shader?
I have this ugly (completely unintentional) glitter effect going on that I want rid of.
I removed the spec, gloss, frenel, bump from the shader itself and it still was there.
I uppded the light shading samples to 6 each and although bertter, they are still there.
Also posted my GI settings and a closeup. Any pointers appreciated.
Antialiasing min2/max4
GI Settings
Render Globals:

10-21-2013, 01:57 AM
When you learn what caused it, please make sure to let us know, so we can do it on purpose.

10-21-2013, 02:07 AM
Indeed. Perhaps LW actually knows that she's off for a night clubbing with the girls. :D

Have you tried upping the AA? I'd give 4/16 a go and see if that helps.

10-21-2013, 05:13 AM
They're hot "pings" from your HDR backdrop... usually from reflection... you sure you've turned all reflective properties to 0?

10-21-2013, 07:24 AM
Your AA settings are a bit low. Make sure your adaptive sampling threshold is set to some thing really low like 0,003.
Sometimes the use gradients option causes art effects. The RPE value is also pretty low but I don't think that is the problem here.

stiff paper
10-21-2013, 08:00 AM
(Can we see what your settings are in the camera tab?)

Other than that, standard problem solving:-
Load the scene, get rid of the hdr. Render (limited region = happiness). See what's changed.
Clear scene, load again, this time leave the hdr there and delete the lights. Render. See what's changed.
If neither of those two gives any hints, then it's time to start knocking out one thing at a time in the surfacing. Eventually the speckles will go away, and you'll know they were being caused the thing you just changed.

Generally, something will start to blow out when it's picking up too much light or reflection. It's usually a question of looking at all your numbers and working out what adds up to what.

I know this is straightforward, but sometimes straightforward can help.

10-21-2013, 08:13 AM
Sometimes the use gradients option causes art effects.

Ah... just noticed that... Not sure if its to blame here specifically... but DONT use gradients with the v11 US/AA system.

10-21-2013, 12:13 PM
Thanks for the suggestions guys !
I increased the RPE to 192 and the glitter is still there.
Using area lights, there is no 'glitter', so it's definitely something to do with the HDR. I had to reduce the imageWorld intensity to 50%, as everything was overly bright when swapping between regular lighting and image based lighting. (is this normal?)
I thought I had removed all spec, gloss and fresnel (I set them all to 0 in the material. I MAY have had some set in the surface panel). I will try again tonight.
The gradients sounds promising. I will try that.

pinkmouse: I had no idea he was a she. Now I'm going to have to do a lipstick shader....

10-21-2013, 02:40 PM
I believe you're witnessing fireflies, meaning difficult of AA to "blur" a very bright sample. My 2 cents suggestions for your tests:

A - Turn on Limit Dynamic (CTRL+F8) and set the Range Maximum value to what suits you better between 1 and 3. 1 might fix it, 2/3 might still fix it but also give you more range to play in post. Or clamp your HDR in Photoshop.

B - Blur the HDR a lot.

Good Luck

10-21-2013, 03:03 PM
pinkmouse: I had no idea he was a she. Now I'm going to have to do a lipstick shader....

Carpaint might be a good start :)

10-21-2013, 10:39 PM
...and the winner of today's "ill buy you a pint if I ever see you at siggraph" competition is....
all of you.
Limited dynamic range - that brought the glitter down to just 'very much brighter than their surroundings' instead of 'holy mother of god' bright
removed gradients, upped the RPE (doubled it) and changed the AA to 6min/12max.
I also dropped the HDR intensity to 38% (from 50)


To recap if you WANT a glitter effect, put your HDR through a brightness/contrast in PShop, drop your RPE turn off limit dynamic range ;)

Render times went from 2 minutes to 7 so I wont be doing many at this quality ;)
Thanks again (and I mean it about the drinks at siggraph)


10-22-2013, 12:50 AM
Glad you got it worked out, useful info. Also, really liking the female albino hairless jackelope!

10-22-2013, 12:00 PM
Actually it poses a problem. Up until yesterday she was male, and I was going to attempt the voice myself.
Now shes female I'm going to have to ask someone to be my "female albino hairless jackelope". I'm not too sure how that will go over with the wife.....

10-22-2013, 01:51 PM
You could try using voice changing software, to turn your voice into female. She's not human so it might work, it could also be funny.

10-22-2013, 04:07 PM
Siggraph!? What? Just send it through the mail to Portugal :D

Glad you sorted it out. I don't see a sex in it, it's just an entity to me :)

10-22-2013, 04:15 PM
Actually rather than using 'limit dynamic range' on the render, you could simply clamp the HDR instead, to stop it giving such sprinkles.

The simplest way to do this is as follows.

When adding your background environment, instead of using an image, use a procedural, and select the node procedural. Add a 2d Image node, set it's axis to Y it's type to spherical and. Plug it into a 'Limiter' node (Tools, Limiter) and plug the limiter into the colour texture input. set the 'high' value to something less than 1000, dial it up or down till you get no sprinkles, but the overall brightness isn't affected. It must be the extreme brightness of the HDR in some spots which is causing the sprinkles...

You also want to make sure your min AA samples are not 1 - I find 4-16 are sometimes needed for highly blurry reflections. Your Radiosity settings are very low. As RH already mentioned, you shouldn't have 'use gradients' switch on, as this is a deprecated function since 11.

10-22-2013, 04:31 PM
Either that, or you enabled the Edward Cullen mode? :D

10-22-2013, 04:49 PM
If you want to skip my tale of woe.... jump to the yellow. :D

I'm glad you worked it out with he/she!.....looks great!

But, I'm still a little adrift with this problem. And have been for some time.

I have several folders/collections of HDRIs. One of which I have particularly good luck with when it comes to lighting/reflections etc.
So naturally, whenever I have given SSS a try I go straight to that collection and run into "fireflies" from hell.
Always thought it was me just not "getting it" with SSS (which is obviously kinda still the case), BUT now I see that it's really more of an HDRI problem.

Never even occurred to me to try one of the other collections. Figured if what usually gives me the best results doesn't work.....
But, :foreheads they work GREAT.... no fireflies.

I would still, however, like to get the others to behave. I tried throwing the "kitchen sink" solutions, as gathered in this thread, at them, but no luck.

Limit Dynamic Range does quite a bit, but I'm in 9.6 and don't have the options Probiner lists. It's just either On or Off.
The processing filter HDR Expose also helps. It gets rid of all the fireflies.... but also kinda sucks the life out of the HDRI at he same time. And I'm not sure I'm using it quite right.

So I ask myself WHY try to force a square peg into a round hole. If it's an HDRI problem.... fix the HDRI.

So I would like to "clamp" in photoshop. HOW DO I DO THIS??
Yes I've googled.... many people mention it, but nobody details how. Is it so simple it doesn't warrant explanation?
Is it a levels thing? Exposure thing? I've tried both.
Do I have to get it into the Merge to HDRI script? Do I down sample to 16bit in order to call up the dialog box with multiple other options?

Please!! Smack me with the ;D stick.

10-22-2013, 04:59 PM

You posted while I was typing. I will try what you outlined.

Do you mean that instead of using Image World or Textured Environment for the HDRI, map it to geometry?
Or, is there a node option in Textured Environment in LW11?....Not sure what you mean by "select the node procedural".

But, I would still like to know the procedure in pshop. :)

10-22-2013, 05:02 PM
I am not aware of an HDR clamp tool in PS... though as I just explained, you can do one in LW no problem...

10-22-2013, 05:06 PM
I am not aware of an HDR clamp tool in PS...

Ah, I only asked because Probiner had suggested it earlier in the thread.

But I do have the other questions about your method above.
(we crossed in typing again)

10-22-2013, 05:17 PM
Oh yes, I spotted it, it's in the 'processing' tab, you can set the limit dynamic range there, probably quicker than what I suggested, though with less fine control :)

10-22-2013, 05:28 PM
You mean HDR Expose?

Yes, that did get rid of fireflies, but also seemed to leave everything a little ..... flat.
Maybe I'm over analyzing.

But I would like to wrap my head around your technique all the same.

10-22-2013, 07:09 PM
AFAIK the problem is because certain pixels in the HRD are overly bright. To fix this you can scale down and blur in photoshop. This will lessen and spread the bright spots
HDR Expose will change the entire image (giving you the flatness you mentioned).
The limiter idea Tobian mentioned will just limit the ultra high values, but keep the rest of the image intact (this would be the way to go)
For my render, I used the same LimitDynamicRange you did (which helped a little), AND doubled the RPE and antialiasing which smoothed the ultra brights, while reducing the HDR intensity a little to tone everything down just a bit. Effectively lessening and spreading the bright spots just like option 1.

10-22-2013, 07:45 PM

I think I have found my next project....... ;)

10-23-2013, 01:12 PM
The limiter idea Tobian mentioned will just limit the ultra high values, but keep the rest of the image intact (this would be the way to go)

Yes, that's the best case scenario.
I'm in 9.6 and didn't get one step of the process.
I had a buddy check for me and it's all clear to me now (and for anybody else out there who isn't quite up to date)....
There IS an Edit Nodes option in the drop down list of procedural types in the Textured Environment window..... Nice.

Can't wait to give that a try when I update soon.

Happy Jackaloping!! And THANKS for starting this thread.

10-23-2013, 03:13 PM
JoePoe, DP has the same concept available http://dpont.pagesperso-orange.fr/plugins/nodes/nodes/Node_Editors.html#NodeText which will work for 9.x and up.

10-25-2013, 10:26 AM
JoePoe, DP has the same concept available http://dpont.pagesperso-orange.fr/plugins/nodes/nodes/Node_Editors.html#NodeText which will work for 9.x and up.

Hey, look at that!!! AWE-SOME!! Thanks :)

10-27-2013, 02:09 PM
very nice work - and I like the glitter as much as the final..

10-29-2013, 11:19 AM
Updated renders on youTube. Updates listed here :