Softer, almost hand-colored look

[MishaBear]

Hello!

I have just started using Luxrender following some simple tutorials, so I know very little.

Anyhow, I wanted to ask you people what are the secrets behind non-photorealistic renders like this one:http://www.luxrender.net/forum/gallery2.php?g2_itemId=13708 - is it mostly a matter of texture and good lighting and colors? Some pieces in the gallery have a "softer", almost hand-drawn feel I would like to recreate for a small project I am doing.

Thanks!

[J the Ninja]

IMO, the biggest difference between the "photo" look and the "drawing" look comes down to the tonemapping. Just clamping the colors down to 8 bit will clip something, and that gives an effect you see all the time in photos, but very rarely in drawings. People tend to draw things as they would see them rather than as they would be in a photograph, so as a result people almost never draw things like lights clipping to white. (also, a lot of the time the FOV in drawings is very different from a normal camera lens (ex, 25-35mm or so), it's either very wide or very close-up.)

Lux's built in tonemapping algorithms are all global algorithms, meaning they work on the whole image at once. You can get a very different look using a local tonemapper in an app like Luminance/Photoshop/Photomatix/etc. Bright objects will get brought down "on level" with the rest of the scene and it helps keep lights looking well defined. Local tonemapping algorithms can have a habit of overblowing colors or sharpening edges too, which tends to give more of the "hand drawn photo" look. Really, all of this is the same stuff that powers the "painterly HDR photo" thing loved by many and despised by others.

I wrote little tutorial in the wiki of how to use Luminance to do tonemapping to get a more dramatic, but somewhat less photoreal look: http://www.luxrender.net/wiki/HDR_with_Luminance


With a lot of my renders, I've taken to putting copies with several different tonemapping algorithms layered together in Photoshop, and blend and mask them to get the look I want in different parts of the image. (for example, using a linear tonemapped base but using a local tonemapped image where the lights are, so they show up cleanly rather than overblown)

[MishaBear]

Jason, this is a great reply, very helpful and gives me so much to work on. Your renders in the article are fantastic.

Thank you very much!

[Ze_Blob]

MishaBear, it seems that your original example was made with SLG 1-7, as says the description.

Indeed it has a nice stylish aspect. I am somehow interested in this kind of effect as i am trying to make a comic strip with Luxrender (or SLG i don't know yet), and i am searching a way to give a graphic look to the 3D renderings.

I have found some interesting treatments in the gmic plugins suite for Gimp: http://gmic.sourceforge.net/gimp.shtml ..like the "graphic boost" one. There are plenty of other possibilities, if you take times to understand the various parameters and find the good mix, not pushing too far the various treatments. Probably Photoshop has a ton of similar and possibly even better effects ?

I think the texture on the wall is part of the drawing impression. It seems to be a flat texture (may be hand drawn ?) without bump mapping, or not very noticeable. The metal of the lamp is a glossy with some obvious bump mapping however.