Advice for setting displacement and SSS.

MatCreator

Hello all, hope all is well. I know its been a while and I am out of practice and touch with things, but I think Ive forgotten how to set these for best effects. You can see the render here: https://www.daz3d.com/gallery/#images/287681/

Its the same model actually, not that that matters. On the left, I am trying to get better displacement, but my attempts cant get the deep groove/cuts in the head. The settings used are shown here: https://www.daz3d.com/gallery/#images/287671 any adjustment causes a slight "seam" to bulge at the edge of the material zone, and more than that the model distorts and swells beyond recognition.

On the right, i am trying to utilize sss, dont really know how that should be set/adjusted. I also set the translucency to 20% (value 1-100%), trying to get "as natural a skin" as possible. Basically the sss is on default settings, except for intensity. You can view that here: https://www.daz3d.com/gallery/#images/287676

Any help, advice, suggestions or opinions would be most welcomed, thank you kindly =)

FifthElement

I would not reccomend doing displacement and SSS on the same model unless polygon count is farely low.

Carrara's SSS can only do "waxy" effect, skin effect cannot be achieved properly, since there are no settings for that (back-scttering forward/backwards and distance, like in Vue, for example)...

Here is example where I used displacement and SSS on the same model with sucess (ice rocks):

https://drive.google.com/file/d/0B4V0tbmTYNaSenA3dC1tenEwSGM/view?usp=sharing

Hope it can help 

MatCreator

Thanks... The model on the left is using displacement, the right SSS, but I didn't know to NOT use both on same model, interesting......

MatCreator

Let me explain a little better... Both heads are the same "object", but they are two individual objects in the scene. The right side is a morph of the left, morphed and painted in zbrush. i imported that object file in carrara, and used the textures generated from zbrush. i didnt use or apply the displacement to the right, but wanted to set up a "fleshy" skin so wanted to make use of the SSS feature in Carrara. The left is the original object, and is using the textures generated from 3d coat. The diplacement maps generated is "visually" similar to the cuts/scars on the head, but with the displacement i expected to see deeper grooves in the skin, and some bulging of the cut sections. But rendered it comes off more like a bump map =/

The SSS to the right isnt really my concern, but I did expect better results from the displacement on the left. They are voxels, so they are "relatively" low in polycount, considering, lol

Dartanbeck

First of all, Hey MC!!! Welcome home!

Can we just bring the images in here for ease of conversation?

If you don't like them in here, let me know and I'll remove them

Render

Settings

Okay, I've only done a little experimenting with displacement so far, but enough to now understand that 50% gray in the disp map is the same as "no change"

So I see that your disp map has nice highs and lows (bright and dark) which helps when we want to raise and lower the msehes surface. But if we don't want it to 'dig in' the mesh, and there's dark in the map. we need to Add 50% to prevent the digging.

So I see that you're multiplying by a value between 0 and 1000. What's that number? Multiplying should make everything darker the higher the number - but I doubt you'll need that to be too high - but use that to reduce raising or lifting of the mesh.

You want it to dig deeper. So let's start by changing the Amplitude from 0.0001 to 0.0002, and see if that's better.

Also try checking out the difference between unchecking Smooth and checking it again. 

You might not need 4 adptive steps, but if the details become too vague or clunky, try going one higher. 4 should be a lot though... but if it's really low poly, try going to 5 if you need more detail.

Start with that amplitude though. Bring that up a little bit and also check to make sure that value 0 - 1000 isn't screwing things up.

 

Dartanbeck

Since that map doesn't seem to go much brighter than 50% gray, perhaps try changing from Multiply to Add?

Dartanbeck

Either way... looks really cool!!!

MatCreator

Thanks for the response, and warm welcome its good to be back... i couldnt figure out for the life of me how to post the images here, thanks for doing that. im still not used to the new format here.

As austin would say, "its toyght". The multiply setting on the displacement map is 100%, any more, and it will stretch. Change the amplitude as you say, and same thing.

I just finished wiping out and then re-installing my entire daz family of programs, two systems even, so ill be going back to that file soon enuff, desperate to get some good results with this file/process...

Dartanbeck

Okay, in that case, maybe try tweaking the displacement map a little by making sure that the parts you need to get the deepest into the mesh are good and black, and perhaps make the rest a little brighter.

The thing is, anything brighter than 50% gray will pull the mesh outward. If you don't want that to happen, try this instead:

Change the multiplier to 50 and then increase the amplitude. I'm not sure if it'll let us go from 0.0001 up to 0.00013, or if four places is it. If we can only go up to 0.0002 as the next level higher, then I'd adjust the multiplier to accomodate that amplitude to remove the stretching.

Man, it's good to see you back around here! Make some more products for Carrara!!!