Activity #1: Studio lighting of a Car

[Samo]

WHY?
Studio Lighting of cars seems to be a recurrent topic in YafRay forums. Blender users usually count on YafRay for this kind of task. This kind of scenes should be an easy task for any YafRay user; yet people have a lot of problems when doing this kind of work (underexposition, HDRI abuse, little appealing scenes, wrong settings, etc).

HOW?
This contest is not going to have a winner. This is a thread to share techniques, opinnions, links, settings, materials and scenes. Everyone is going to win. The main points of the final renders should be:

- Lighting
- General shaders.
- Scene composition, camera angle
- Postprocessing (if you do so).

Don't get lost in details, the aforementioned points are the most important ones in this contest. You should work in your render as if you were going to sell this car, as if your render was going to be used in an advertisement about it.

for this activity you can choose between

the Bugatti Veyron 164. You can download the Blender scene here:
http://www.megaupload.com/es/?d=BJZP5Q38

Ferrari Enzo, modelled by come2me
http://dl.free.fr/iGDk9jTX8/enzossmat.rar
http://www.mediafire.com/?udls51z5aa8
http://www.megaupload.com/es/?d=C8C3AK43

USEFUL LINKS about Studio Lighting
http://www.3dm3.com/tutorials/vray_render_studio/
http://forums.cgsociety.org/showthread.php?t=224337
http://www.netcarshow.com/bugatti/2004-eb_164_veyron/
http://www.studiolighting.net/lighting-automobiles/
http://www.computerarts.co.uk/tutorials ... etter_cars
http://www.peugeot-concours-design.com/index_en.htm
http://www.youtube.com/watch?v=HXNR9_zhWY8 OMG!
http://www.computerarts.co.uk/tutorials ... o_lighting
http://www.elmundo.es/elmundomotor/2011 ... 09104.html

[olivS]

should be interesting... I'll try to join in... count me in!

[Lynx]

This sounds like a perfect occasion to show what the new core design is able to deliver...and actually, i'm curious to find out myself!

I won't have time the next few days, but i will definitely give it a try. Maybe it also brings up a few ideas about better blender integration of the new features etc...
I just got my new 64bit machine up and running, however with 64bit blender scenes still not fully functional i don't know how far i get, probably will not be able to share the scene until i bite my way through that 32bit environment with chroot...(get that darn scene format fixed, blender dudes!)

[eeshlo]

I just got my new 64bit machine up and running, however with 64bit blender scenes still not fully functional i don't know how far i get, probably will not be able to share the scene until i bite my way through that 32bit environment with chroot...(get that darn scene format fixed, blender dudes!)

I have been using blender compiled for 64 bit linux without problems for more than a year now. The only real problem is with library linking, appending stuff from other blendfiles. So long as you avoid that, there is no problem really. I only had one crash because of this, I tried loading a file from a bugtracker report which used linked data from a library blendfile.
There is one other problem which as far as I know still exists. The dna struct tester fails with some structs, not detecting proper alignment, which caused a lot of problems for me at one time. I solved that and notified Ton about it (several times, also sent a patch), but he might have forgotten about it again...

[olivS]

OK, so I am the one to start. I had big difficulties to find a good lighting scheme: I have enclosed the scene within a half-uvsphere, with openings N-S-E-W and at the top of the UVSphere. But the Sun lamp outside was note sufficient to lit the scene.

So I also added 4 rectangular Area lamps (matching roughly the size of the openings) along with Photon lamps (100,000 Photons each).

But most of all, I had to boost EmitPwr up to 12.5 and Exp to the max (10).

For the Gi, Depth is 3, CDepth 5, Cache and Photons activated, 500,000 photons (Radius 1.5 and Mix Count 100).

Hereafter the micro-render I did, resp. Quality Low, Medium, High, Higher, Best.







Next steps would be to play a little more with Radius and Mix count, but before, i'd like to revert to Medium Quality and enhance the scene in order to make it more appealing than these first tries.

The car body is Fresnel material but not perfectly reflecting. I need to rework some shaders, obviously, just a first try, too.

[Samo]

nice render Olivier.

I'm a bit concerned about your exposure settings, yafray should be able to render that using less exposure.

I think you can solve this by making bigger the photon areasources (and their associated 'emit' meshes, you are using 'emit' meshes, aren't you?), and by reducing the enclosing box. What your 'stored photons' and 'pregathering' values are?

I've only modelled the tires and wheels. In the camera view you have choosen, the tires I've modelled don't seem to be wide enough... for this "1001 horsepower" beast

PD: Emitting objects explained here:
http://wiki.yafray.org/bin/view.pl/User ... ayLighting

[Lynx]

Thx eeshlo, so i will just give it a go...although i have already setup most of the chroot stuff, am curious about the (real) performance difference betwee 32bit and 64bit code, since most people compare apples to oranges...if not grapefruits.
Just curious, did you ever try to load your files from 64bit blender with a 32bit version?

I've only modelled the tires. In the camera view you have choosen, the tires I've modelled don't seem to be wide enough... for this "1001 horsepower" beast

Hmm..."slightly" too small
Btw. rar files are still annoying for linux users...

[Lynx]

Ok i couldn't resist, so i took the time



Rendertime 3min 33sec (Core 2 Duo E6600)
Pure path tracing, tried to achieve a subtle metallic effect on the red paint.
I forgot to asign material to rear bumper, headlight not done either. Also more GI bounces would probably light up the interior correctly.
And I clearly need to implement better AA filters finally...

-edit-
oh totally forgot: Used 3 (visible) area lights

[olivS]

OK, I took back Exp down to 1.000 and slightly increased EmitPwr to 75.00.

Here's the results:



In order to answer to your questions, Samo:

* no I'm not using emit meshes, only Area Lights and Photon Lamps.
* here are the 'stored photons' and 'pregathering' values:

Shooting photons ... OK
Emitted 99856 Stored 11569 search 200
Pre-Gathering (11566) ... OK 11566 photons kept
Shooting photons ... OK
Emitted 99856 Stored 11496 search 200
Pre-Gathering (11494) ... OK 11494 photons kept
Shooting photons ... OK
Emitted 99856 Stored 8842 search 200
Pre-Gathering (8842) ... OK 8842 photons kept
Shooting photons ... OK
Emitted 99856 Stored 11255 search 200
Pre-Gathering (11255) ... OK 11255 photons kept
Finished setting up lights

Comments are welcome.

[Samo]

Code: Select all

I'm not using emit meshes, only Area Lights and Photon Lamps

Use emit meshes in conjunction with arealights. That will allow you to reduce your 'exposure' and 'emitpwr' values. Explained here:
http://wiki.yafray.org/bin/view.pl/User ... ayLighting

Increasing light & mesh size should help too

[eeshlo]

Just curious, did you ever try to load your files from 64bit blender with a 32bit version?

Yes, I do that all the time, I also always get the official builds and have had no problems with it.
I also have used files saved in 64 bit linux with 32 bit windows, no problems.

[olivS]

Use emit meshes in conjunction with arealights.

I will try tomorrow, if I have some time (hey, Valentine's day, this evening!)

I relayed this thread on http://www.linuxgraphic.org in this thread:
http://www.linuxgraphic.org/forums/viewtopic.php?p=17445#17445

But at the moment, it seems that i'm the only one involved in it

[avariant]

All right, here's a first go. The model's been stripped down for faster renders. I'll add the rest at the end.

Scene lighting by 4 area light / emitter pairs. I always like the aircraft hanger / industrial garage look. And who can resist the ground effects package (one area light / emitter).



One issue I've always sort of had: On large smooth surfaces, the mottled look you get when using GI with just the emitters and area lights. What should I tweak to smooth that out? Should I just throw more samples at it? More photons just seems to make it more noticable. Maybe larger search (using 50)?

I'm using Wings, so direct XML editting.

[avariant]

a little variation. This actually uses a single area light / emitter facing diagonally up, with two curved reflector plates above the scene. Obviously, path light depth has to be 2 or more. I think it provides more of a diffused lighting, but maybe it's just a round about way to do what could be better done with direct lighting. Anyway.

Full model, a wider-than-normal angle lens.

[Samo]

hi guys,
thanks for participating. Finally I've got time for preparing some renders:
Work in progress.

BTW, the yaf(A)ray render looks impressive!




TODO things:

- The scene needs rim lighting in the back side
- Materials