Page 1 of 2

Organic stuff

Posted: Thu Nov 24, 2016 6:23 am
by Mihai
I'm testing workflows for creating realistic 3D scanned organic stuff, and trying to see in which cases SSS is necessary or not so much. In the case below (pastry stuff) it seems SSS is very much necessary. Render is at SL 14. These are "low poly" retopologized meshes (10K polys), with only a normal map. No displacement used in this case.

Image
Image

Re: Organic stuff

Posted: Thu Nov 24, 2016 11:34 am
by luis.hijarrubia
It's more difficult to see the difference if you change light direction between images.

...

Now i'm hungry.

Re: Organic stuff

Posted: Fri Nov 25, 2016 2:23 pm
by Hervé
cool... looks a bit solid... :)

ps.. please change that low res wood.. it hurts my eyes 8)

Re: Organic stuff

Posted: Fri Nov 25, 2016 6:52 pm
by Mihai
Oui chef! You are right, I've tweaked it already to make it less solid looking and not so overall yellowish. I'm still in the process of testing different SSS approaches to see which behaves the best and works ok under different lighting. This is one under strong sunlight:

Image

Sorry about the wood again....

Re: Organic stuff

Posted: Fri Dec 16, 2016 12:32 am
by Mihai
More tests. Bread and nuts. The nuts were more difficult than I thought....smaller objects are harder to get in focus.

Image

Image

Re: Organic stuff

Posted: Mon Dec 19, 2016 1:13 am
by PA3K
Hi Mihai,

what hardware are You using for scanning 3D objects?
Amount of sss or thin sss can be calculated from different lighting setup during scanning (just idea).

Patrik

Re: Organic stuff

Posted: Mon Dec 19, 2016 1:27 pm
by tom
I think the pastry stuff looks oversaturated. :roll:

Re: Organic stuff

Posted: Mon Dec 19, 2016 1:46 pm
by Mihai
PA3K wrote: what hardware are You using for scanning 3D objects?
Amount of sss or thin sss can be calculated from different lighting setup during scanning (just idea).
For the moment just cross polarized light and Calibrated Eyeballs (glasses) :mrgreen:

Tom, yes I need to redo the pastries a little bit, I have a better idea of what to do now after a few scans.

Re: Organic stuff

Posted: Wed Jan 11, 2017 12:16 am
by Mihai
Another test with a photogenic squash.

Image

Re: Organic stuff

Posted: Wed Jan 18, 2017 2:25 pm
by NicoR44
Very nice Mihai!

Re: Organic stuff

Posted: Wed Jan 18, 2017 7:46 pm
by Mihai
Thanks Nico :) Here are some more I finished recently:

Image

Image

Image

Image

Image

Image

Image

Re: Organic stuff

Posted: Wed Jan 18, 2017 8:33 pm
by abed-sabeh
Wow...great work. Could you send me some please? :D It's time for some baked sweet potatoes and a pumpkin pie :D But thanks giving is over :)

Re: Organic stuff

Posted: Wed Jan 18, 2017 10:03 pm
by dk2079
cool, these are very convincing.

I think you got a great match on the flat colours on the pumpkin.
you don't see these outside the season, but I remember some of them have an unusually satisfying rendition of colour;
somewhere magically in between flat and specular.

on thing I am wondering in technical terms, these are scans, I guess, so surface detail comes directly from the mesh?+normal map?
because the one thing that bugs me is the tangents. some of the pumpkins look a bit like "cut out"

this is mainly due to the wood background (still:) not matching the quality of your main subjects, but I think it is also due to the pretty smooth base surface. some very slight displacement might add some more realism in that particular spot.

Re: Organic stuff

Posted: Thu Jan 19, 2017 5:33 am
by Mihai
Most of these have a pretty smooth specular in reality, except the last big pumpkin. Especially when lit with strong emitters as here. You realize just how specular they are when using cross polarization to remove it. They are retopologized meshes which use both displacement and a normal map. The normal map is created both from the high rez scan plus blended a bit with a normalmap created from the resulting diffuse texture. So the nice thing is the base meshes are pretty low poly and the normal map alone does a great job on far/medium shots without needing to use displacement. You can increase the displacement of course but I tried to match it pretty well with how they are. I'll do some renders without the diffuse map and you'll see better there is displacement. At least, I hope I had it on for all of these...this is why getting feedback is important :P

After these I'll make a collection of pastries and desserts :)

Re: Organic stuff

Posted: Thu Jan 19, 2017 9:25 am
by Mihai
Double checked that displacement was on for these and did a quick test:

Image

Raw scan mesh (about 3 mill. polys) is on the right, disp + normal map on the left. I agree it seems the silhouette shouldn't be so even with some of these, but it is :)