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View Full Version : Realistic car city scene; Global illumination or fake it with lights and occlusion?


earwax69
06-09-2009, 01:29 AM
Hi, im doing a car ad. Some scenes are on a mountain highway (cliche I know), other in a city and on a bridge.

I did a test for the mountain road with Global illumination and it look ok but i was wondering how to get rid of the artificial feeling. I know its all in the details but I wonder how people who work frequently on car ads do.

As for the car, its all about reflection. I guess the car will look real in both cases.

mmm... maybe I should just crank up the motion blur then we dont see anything anymore!! :curious:

thanks!!

mister3d
06-09-2009, 03:21 AM
Could you show the render? Maybe people would suggest why it may be artificial.

You shouldn't crank up motion blur without a proper reason: setting it higher than 180 degrees (0,5) must be motivated, for example by a dark scene, when you need more exposure. Setting it over 1 is unnatural in any case I think.

earwax69
06-09-2009, 02:19 PM
With a bit of compositing:http://img188.imageshack.us/img188/6558/city0300000.jpg
(the wheels are not moving...)

The original render... It is the one we should optimize:
http://img26.imageshack.us/img26/2344/city03original.jpg


And this one in the mountain, with a tiny bit of compositing... (saturation+lights), that one need some work obviously.
http://img44.imageshack.us/img44/1871/mountain0300000.jpg

Made in Lightwave. The Audi model come from the web, all credits to the uploader, I just did the shading. It's just a test, nothing commercial.

earwax69
06-10-2009, 09:09 AM
I've just made another one. Motion and dust will be added later. I will smoke the car windows too.

http://img8.imageshack.us/img8/17/deserttest04.jpg

noouch
06-10-2009, 02:59 PM
Does the reflection on the car paint shader have a fresnel falloff? What sort of paint is your shader based on?
Are you working in linear color space?

earwax69
06-10-2009, 04:16 PM
Yes, the car paint have a fresnel shader. I dont know too much about color profiles... except that quicktime screw my colors with most codecs!! :shrug:. I saved the rgb image in jpeg from lightwave, imported it in After Effect (8 bits mode) for make adjustement. I will use uncompress for the final of course and probably use 16bits in AE.

ienrdna
06-10-2009, 08:48 PM
Reflections arent motion blurred. you should look in to basic compositing foundation also ligting and color theory.

mister3d
06-10-2009, 08:55 PM
Reflections arent motion blurred. you should look in to basic compositing foundation also ligting and color theory.

That's correct: if you use 2d motion blur, it doesn't see reflections as traced image, but as a plane. So you must use real motion blur if you have mirror-like reflections.

phix314
06-10-2009, 10:31 PM
I'd say it's the materials. The headlights are lacking some shine.

But you're right.. its hard to put my finger on just what is making look artificial. Have you tried some sister HDR domes + backplates?

mister3d
06-10-2009, 11:45 PM
Now when I look at it I see several problems:
-the reflection of the car bodywork could be stronger
-the reflection of the windshield is odd: check whether it has a proper geometry and fresnel falloff
-the car shadow in the first shot looks too sharp, look how soft the surrounding shadows are
-the colors must be adjusted to the environment more precisely, no the car looks violet in all the shots
-maybe some edge blurring could be done in some shots

Some my quick overpaints, maybe thye may be useful to you.

http://img196.imageshack.us/img196/7442/mountain0300000copy.jpg (http://img196.imageshack.us/i/mountain0300000copy.jpg/)


http://img196.imageshack.us/img196/2685/deserttest04copy.jpg (http://img196.imageshack.us/i/deserttest04copy.jpg/)

earwax69
06-11-2009, 01:05 AM
Wow thanks Mister3D... just what I needed!!

Thanks for all your replies.

Im gonna tweek it a bit before starting animating.

EDIT: Here it is after few changes. More reflective, front lights are lighter, annihilated the blue in the car shader. All colors are only reflection now. Smoked the windows a bit.

http://img37.imageshack.us/img37/3568/deserttest06comp.jpg

ndeboar
06-11-2009, 03:19 PM
as mentioned before, when im doing car renders i crank up the frenel in the reflections. Seems to make things look nice.

Anyway, For me, this is why this looks a tad "Fake".

All of your enviroments are quite overcast, but your shadows are all reaally hard. Soften your lighting up a bit.

If your going for real, then a bit of noise, chomatic aberation sometimes helps.

Kabab
06-11-2009, 03:33 PM
Biggest problem I see with your car is the paint has no depth..

Car paint is really layered you need to re-create that effect...

So this is how we go about it...

You want a diffuse + ao layer (good quality AO map really helps)

Then you what a spec layer it can be a good idea to use a noisy spec map (gives metallic look (same colour as diffuse but lighter and the noise spec's white)then on top of that layer a ferensal reflection map..

In Maya we normally use a layered shader or the mia material which pretty much does the same thing... a phong shader for the diffuse+spec+ao and blinn layered on top for the reflection..

Give your paint depth!!!

B4C
06-13-2009, 07:14 AM
This is partly for my own growth, but it may help as well. The feeling that I get is that the camera is following the car at the same speed so the car is not blurred, but the background is. Should there not be a pretty even distribution of motion blur on the background in that case? It also does not seem like there is any depth of field at the moment. It is particularly noticeable in the city scene. Please correct me if I am wrong.

earwax69
06-15-2009, 01:09 PM
Hello! Im still working on it and im rendering full time on both my workstations. Damn its long though... 5 to 15 min per frames and I've got 16sec to animate.

I have changed quite a lot of things and will upload some frames soon.

B4C; Yes, there is no Depth of Field, I will add it in post if needed. As for the motion blur, things near the camera have more because the perspective make them move faster than things in the back. The cam and the car are indeed almost at the same speed!

Kabab; I changed the car paint totally. I think its better now. I will upload an exemple tomorow. As I am using LW, things are a bit different... I didnt put an occlusion pass but I guess the Global Illumination is doing that for the diffuse anyway.

earwax69
06-19-2009, 01:27 AM
Here an animation test:

MIX All 2_test 1.mov, QT sorenson, 25.7mb.

http://www.filefactory.com/file/ag709af/n/MIX_All_2_test_1_mov
http://rapidshare.com/files/246104748/MIX_All_2_test_1.mov.html


I've made the soundtrack this morning in Reason!! It fit quite well I think.
As the quicktime colors are all off (thanks Apple for never correcting this!) I join few jpegs with the real colors.



http://img200.imageshack.us/img200/2747/mixall200000.jpg
http://img198.imageshack.us/img198/4214/mixall200056.jpg
http://img132.imageshack.us/img132/7571/mixall200109.jpg



http://img268.imageshack.us/img268/6650/mixall200130.jpg
http://img44.imageshack.us/img44/1804/mixall200175.jpg
http://img41.imageshack.us/img41/7475/mixall200231.jpg



http://img188.imageshack.us/img188/7583/mixall200244.jpg
http://img44.imageshack.us/img44/9152/mixall200275.jpg
http://img188.imageshack.us/img188/6019/mixall200350.jpg



Its not finish, there is flickers in the windows, no car driver and few other stuff to correct. Also I will make a last scene, finishing in a studio.

earwax69
06-19-2009, 03:28 AM
And here heavily color corrected:

MIX All 2_test 2cc.mov, QT sorenson, 25.7mb.

http://www.filefactory.com/file/ag71dh8/n/MIX_All_2_test_2cc_mov


And here few frames:

http://img197.imageshack.us/img197/2738/mixall200104.jpg
http://img223.imageshack.us/img223/6753/mixall200212.jpg
http://img198.imageshack.us/img198/2150/mixall200311.jpg

nigerrrever
06-19-2009, 11:16 AM
Realy nice results! :thumbsup:

i like the city part,most realistic..


i had and still have a lot of ideas for cool car ads,but i have problems on rigging the car,rendering and composite it .. so i will pause this for a time.


What was the rendering time rate per frame?

earwax69
06-19-2009, 11:39 AM
wow, thanks for say the city is realistic because I was thinking it was the main weakness of the clip... the city and the trees. Maybe when you look at it for the first time you dont notice all the wrong stuff in it!! :curious:

Its all at 30fps for now... maybe I'll try some 24p for filmlook but I dont think so.

Its quite incredible the time it take to do... rendering is now very long (6-8min per frames because of the GI cache and motion blur) making the process quite tedious. I wish I had a quad computer!!

nigerrrever
06-19-2009, 01:02 PM
wow, thanks for say the city is realistic because I was thinking it was the main weakness of the clip... the city and the trees. Maybe when you look at it for the first time you dont notice all the wrong stuff in it!! :curious:

Its all at 30fps for now... maybe I'll try some 24p for filmlook but I dont think so.

Its quite incredible the time it take to do... rendering is now very long (6-8min per frames because of the GI cache and motion blur) making the process quite tedious. I wish I had a quad computer!!

I watched the city part few more times,and the single thing that doesen't look good,is right when the city part comes till second 6 of the clip..

i'm talking about the "end of the road" ,it was ok if some fog where generated there :wip: .Anything else looks good,traffic,buildings,background and also the car paint material is cool


everything can be improved,you just need time for this kind of stuff (animations :D)

and yes,I wish I had quad too lol

bolajiojo
06-26-2009, 10:56 AM
your render looks great:eek::buttrock: can you post your car paint settings as well as your render ettings it would be a big help the rendering of my car odd and i would apreciate your help i use lightwave thanks:applause::applause::applause::applause::applause:.

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