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CAClark
08-28-2002, 04:51 PM
I'm looking for suggestions on how best to emulate the kind of Deep Flake Metallic Paintwork that some cars have? I'm using LW.5 and would be appriciative of any help.

Cheers

Craig

Tumerboy
08-28-2002, 05:49 PM
I don't know if I even know what the paint is that you're looking for, but if it's the stuff where the car is say, green, and then has little flecks of reflective thingies in the paint, that makes it look different colors from different angles, hopefully this will help.

I'm not too sure. . . I think the best result may come from copying the body of the car, and expanding it by a millimeter or so. . .

Then texture the underlayer with the actual paint/flake texture, (I would use some procedurals for the flakes)
And the top coat would be, well. . . the top coat, that would be the overall shiny layer, and would be the actual reflective layer.

Now on your little reflective flecks texture, take that and make it into a black and white image, or if it's procedural, then copy that.

Put it in the color texture channel, as an alpha.

Below that, put a gradient of the different colors you want those flecks to turn, and change the type to "Incidence angle"


Hope that helps. . .

Let me know if you get something working

Eugeny
08-28-2002, 06:51 PM
Use BRDF shader - u can combine up to 3 layers with different specular (settings or modes - anisotropic or regular).
So u can get anisotropic for metal and another layer for coat with regular specular. Also u can define color for specular.
Here some thread about metal and car paint (see page 4 for Leigh BRDF tut)
http://www.cgtalk.com/showthread.php?s=&threadid=12668&perpage=15&highlight=metal&pagenumber=4

Tumerboy
08-28-2002, 07:10 PM
Eugeny I think that would work except that CA needs more complicated specular than just glossyness etc.

jan_muentinga
08-28-2002, 07:55 PM
:wip: he is working wit lw5,
there is no brdf.
you could buy worleylabs gaffer instead.
good luck..
jan

Eugeny
08-28-2002, 07:59 PM
...oops :hmm: in this case the offset method is best for u :)
Eugeny I think that would work except that CA needs more complicated specular than just glossyness etc.
The BRDF shader is not only specular - by getting higher specular it's lower the diffuse channel (just read the Leigh tut)

mohh
08-29-2002, 03:43 AM
F.Y.I. I uploaded the presets I had on there before, just in case anyone wants them again. They use BRDF so it wont work in lw5...

CarPaint Presets (http://www.mohhs.com/lw/carpaint.zip)

NanoGator
08-29-2002, 07:13 AM
I'd make an image in Photoshop at 512 by 512 that's 50% gray. Then I'd add noise to it and slightly gaussian blur it to make the speckles. I'd apply that as a specularity texture. Then I'd make an image in Photoshop that's the color of the car. (Tweaking this image is easier than keeping track of a bunch of RGB values...)

I'd render it in 3 passes, though:

- Normal render...

- Turn off all the 'diffuse' switches on all the lights and do a specularity only render with the surfaces's glossiness changed. (car paint has two levels of glossiness because of the paint and the coating, that's why BRDF is so interesting...)

- Then I'd do a reflectivity pass. Basically, I'd texture map a polygon with a picture of a lesn flare and place it about where the light is. Then I'd make the car reflective so that you can see the textured lens flare reflected in it. This'd simulate the reflection of the light source.

Then I'd comp them all in Photoshop, Premiere, or After Effects. (AE would be my first choice...)

:)

CAClark
08-29-2002, 09:30 AM
Thanks guys. I should apologise for the type, as Lightwave.5 was meant to read 7.5, sorry.

I'll be trying these suggestions at lunch time, and thanks for the link to your presets Mohh, am gonna check those too.

Cheers

Craig

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