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cholo
05-20-2004, 08:10 PM
This is some work I'm doing for DaimlerChrysler. The model is not mine, but rather purchased at 3d02.com, although all the lighting, surfacing and some parts (many) I had to correct from the purchased model are done by me (I wish modelers who work for that site had better reference material available to them). Other than that, the scene contains one light, no radiosity, shadows off, etc... The usual tricks and I'm rendering at 30 seconds per frame. The image was only adjusted with curves in photoshop and some sharpening was done. Enjoy :)

Zarathustra
05-21-2004, 06:26 AM
Wow, well I'd like to know more about the surfacing then. One light, no shadows. cool

emoboy83
05-21-2004, 06:48 AM
i too would love to know about the surfacing and light set up. especially because of the quick render.

cholo
05-21-2004, 10:56 AM
Well, first off thanks for replying. I'd like to share with you some of what I've learned in the past few years. I've spent most of my time not only inside lightwave, but also doing commercial photography both on film and video/digital. When you go into a stage to shoot a car you're faced with lots of problems. You want the car to look good, you want to accent it's lines and shapes with light, you want to have some contrast in your flat body panels, you want it to have depth. This is not easy, you need tons of light and this means not only setting up 20 or 30 thousand watts worth of spotlights, but also flagging them correclty so they don't reflect in your car, adjusting your reflective surfaces, add black fabric to your set, paint it, clean it, etc... And in the end most of your frame is completely useless because all this can be seen in camera and you need to retouch the images to get rid of all the junk. I'll include below a few samples. Now in the computer it's fun, because you can choose what your car's paint sees and what your camera sees. You can make a set that you can go around 360 degrees in and have any angle look good. You can make parts of your set follow along with your camera, you can use negative lights, etc... In the real world this is also true, you'd be surprised how much spray paint is actually used to retouch certain areas of the car to look perfect... Tires are spray painted black, grilles, brake discs are spray painted chrome... (one piece of advise, never buy a car that's been used to make a commercial, they are thoroughly abused)

So in the end the lesson is this... It's not how it's supposed to look, but rather how you want it to look. In lightwave the best way to achieve this is by using gradients. Notice the shadows in the wheels? It's a gradient dependant on the x axis distance to pivot controlling the suface's diffuse and reflection channels. The car paint is achieved by some clever use of incidence angle controlled reflection, specular, glossiness and diffuse. My only light is a distant light falling perpendicular on the car to have an even lighting condition all around the car so I can travel 360 degress around it set at around 60% with a 20% or so ambient and I start building from there. I build two different sets, one that the car will reflect and one the camera will see. I paint the shadow underneath the car in photoshop and map it onto the camera set. The reflection set has a darker ground with some gradients and turbulence so it's not dull but rather brings some contrast to the paint. You can see this reflected on the door panel. It also adds a sense of reality because it looks like lights falling on your real life set. An outer shell in the reflection set has a wall with a gradient going from 200 or 300 percent luminance to 100 percent simulating the outer walls in a stage lit from below behind the black fabric used in real life as both a flag to prevent light from spilling onto the car and to make a horizon visible on the surface. Lastly you need a big square on top of the car that you should add "hotspots" to using gradients to simulate a bounced light. This one you use to paint your lines with so you have to play with both the angle at which you place this square as well as the placement of your luminance hotspots. In real life this part is nice because you have realtime feedback, but all you fprime users out there have an edge for this. I myself still rely on the old F9, maybe I don't treasure my sleeping hours as much as I should :) Same goes for interios, a gradient can make the bottom of the cabin seem darker than the rest. I also make the windows a little darker and very reflective to minimize what you can see inside. Last, If you need to add some darker spots on your car inside hidden zones you can do this with a vertex map controlling the diffuse channel on certain areas, but generally in a set like this in real life there's so much ambient you rarely get any darker zones so less is more.

If you play around a setup like this for a while you'll make it work in a day or so. Basically the surfacing is the trick and you need to re-surface your car if you switch to a different scene, but this could also work for exterior shots. Just parent your shadow to your car and you can move it. Btw, if you need some soft reflection on parts like aluminum or such, just use an enviromental map for your reflection instead of ray trace and don't bother with trying to make real reflections look soft, you'll never know the difference as long as you make a picture in photoshop that approximates what you need it to reflect and make it very blurry.

Hope this is helpful to all you 3d car enthusiasts out there. I'll post another shot below for your viewing pleasure.

cholo
05-21-2004, 10:56 AM
And another...

cholo
05-21-2004, 11:01 AM
And this is a real life photo like I described earlier. This is a truck, but I'll be shooting the Crossfire next week so I'll post a photo from that one later on.

grahamtuck
05-21-2004, 12:22 PM
Are some of your shadows Photoshoped?

jgaris
05-21-2004, 01:33 PM
I think your image is better looking than actual car! You make the Crossfire look cool!

Great Job :D

wrosado
05-21-2004, 02:07 PM
Hey Cholo

Thanks for the explanation of you lighting/surfacing techniques...

it's amazing how many different ways there are out to to achieve these great looking images...

now i'm gonna read your process again and see if i can use it in my work!

thanks!

cholo
05-21-2004, 03:01 PM
Here's something different. I wasn't happy with the classic white limbo as an environment for the car so I decided to try something different. I only had to change the camera viewable set and left everything else the same. What do you think?

cholo
05-21-2004, 03:01 PM
Oops.

sKb875
05-22-2004, 12:27 AM
WOW :O I wish I could render like that.. I'm gonna have to follow the tutorial that you made.. You should make a video tutorial on how you did it. :D That would be awesome to see..
...Hopefully I can do a render atleast 1/3 as good as you can..

emoboy83
05-22-2004, 08:14 AM
hats off too you cholo. not only can you render a beautiful scene but you also use your time to impart some of your obviously extensive knowledge on us newbies. i will be saving this explanation as future reference for texturing my latest models as it is that good. again thanks a lot and i love the new renders.

Zarathustra
05-22-2004, 09:04 AM
Thank you very much. I'll experiment. I don't get called to do cars, but I think your approach could be applied to other things. I'll certainly acknowledge when a future render of mine benefits from your tips.

UnCommonGrafx
05-22-2004, 10:03 AM
Cholo,
A heartfelt thanks for all you've shared. Truly, a treasure!
Great information and techniques. Wow.

glassefx
05-24-2004, 01:15 PM
Your refreshingly cool!

And you like to share your knowledge also...

See you around!

cholo
05-31-2004, 08:53 PM
As promised, heres the live shot I did of the real thing.
I'll post some images of the studio setup tomorrow so you can see how the picture was made.

emoboy83
06-01-2004, 04:58 AM
wow, cholo you are truly incredibly multi talented. is that the origanal shot or is it photoshopped a bit.

cholo
06-01-2004, 11:08 AM
The only thing done to the image in photoshop is a little sharpening and some contrast adjustment, nothing major. Here's a photo of the studio setup so you can get a better idea of how the car's environment was done.

emoboy83
06-02-2004, 12:46 AM
you make me want to give up graphic design and become a commercial photographer!

cholo
06-02-2004, 09:31 AM
Why not do both? Being multi-disciplined can give you an edge for these things, plus it's fun :)

iandavis
06-02-2004, 03:55 PM
some be-yute-ee-full rendering there cholo,

one question... what level of AA are you using? Is the original image being scaled by this page?

cheers

emoboy83
06-07-2004, 12:09 AM
ha, almost finished my design course and im thinking of doing photography and want to learn lightwave even more. ahh too much to learn.

wave
07-31-2004, 12:36 PM
Iīm glad I found this threat, because I made a Crossfire on my own in Max a few weeks ago and wasnīt quite satisfied with the results (the best one shown at the end of this reply :) ) I know there is something wrong with the reflections on the cowl and I will hide the spot reflecting in the window within the next renderings... and - right now - I am trying to simulate the photo-set you presented and work with gradients in order to achieve better results :) ....

I posted several renderings in several forums and some of the replies criticised the mats and the reflecting ground so i would like to know: is it a faux pas having the ground reflecting the light-boxes?


btw.... amazing work with your Crossfire - canīt believe you render with 30 sec/frame....

greetings



http://www.wavestone.de/threats/FINAL_10_DT_klein.jpg