Forum: Carrara


Subject: Not quite reinventing the wheel

pauljs75 opened this issue on Apr 01, 2009 · 12 posts


pauljs75 posted Wed, 01 April 2009 at 11:16 PM

Just rendering one, that's all. But in the process I got a few questions.

Other than that, things work pretty well. Did the test render seen here. Next up will be to do some displacement mapping for the tire. As for its coloring, the standard metal black-patina makes for a half-decent rubber substitute. It's just this way at this stage to show the UVs on that part.

As for why I'm rendering this wheel? I need something to inspire me to make a decent car model. I've been doing other stuff for a while and need to touch-up on the 3D again.


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pauljs75 posted Wed, 01 April 2009 at 11:25 PM

Playing with displacement this time around. Using a 1024x1024 map to drive the channel. Just showing the brightness values from HSB here to get an idea of how far it should go. I'm also seeing some artifacts around the edges when using displacement mapping. (Other than the obvious area where I didn't overpaint the texturemap by enough.) Displacement didn't seem to do much unless subdiv is enabled, and then the samples has to go up a good bit to make text legible. Any recommendations about changing some of the other values from default?

Also it seems like using displacement is quite a tradeoff for calculation time at render time. But it's either that or perhaps using a poly-bomb tire model I have sitting around, and I'm not sure if I want to stage with a couple of those in the scene.


Barbequed Pixels?

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Also feel free to browse my freebies at ShareCG.
There might be something worth downloading.


bwtr posted Thu, 02 April 2009 at 12:18 AM

pauljs 75

These are my efforts made in MoI for Carrara. and, with others, in the Browser.
No displacement is necessary--the tread is fully modelled.

Just can not imagine getting an adequate result using displacement?

The .car file size for the tyre with rim is 3.04 MB.
(anyone can pm me if they need it)

Brian

PS---any of the file type exports that I have made from MoI seem to only have part numbers

bwtr


bwtr posted Thu, 02 April 2009 at 12:30 AM

These are the MoI file save formats (plus AI) Brian

And another PS---Would it not be best to use the Carrara 3D text for the wheel numbers?

bwtr


bwtr posted Thu, 02 April 2009 at 1:06 AM

The possible Carrara Text alternatives---if of interest/value.

Brian

bwtr


GKDantas posted Thu, 02 April 2009 at 7:15 AM

Can you post your displacement image? You need to use gray scale to dont get those distortion...

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GKDantas posted Thu, 02 April 2009 at 7:22 AM

Here an example with a image (1024x1024)... after create the image give it a little blur:

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MarkBremmer posted Thu, 02 April 2009 at 9:46 AM

 To answer your original questions:






pauljs75 posted Thu, 02 April 2009 at 10:51 AM

Here the displacement map used in the one screen shot. Note that it's obviously just to test how strong a displacement each value presents. But I'd still like the text portions to come out a little crisper. So the sample value had to be on the high side.

When I get around to doing the actual tread pattern, I'll do something better. But I notice already that I'll probably be using a brightness range of 30 - 70 for the sidewall stamping and siping of the tread. (Seems easy enough, since a HSB brightness value of 50% at 0% saturation is the same as using 127,127,127 in RGB, but more straight forward.)


Barbequed Pixels?

Your friendly neighborhood Wings3D nut.
Also feel free to browse my freebies at ShareCG.
There might be something worth downloading.


pauljs75 posted Thu, 02 April 2009 at 11:22 AM

And I found I had a lower poly version of the really high poly tire. (And then use Carrara's render-time smoothing.) I think this one comes in under 20K, but with just a smooth or two it goes north of 80K. Something mostly to do with the mesh of the tread pattern. I still think it might be a plan-B though. I figure it would be easier to change a mapped tread around than re-model that kind of thing.

Barbequed Pixels?

Your friendly neighborhood Wings3D nut.
Also feel free to browse my freebies at ShareCG.
There might be something worth downloading.


MarkBremmer posted Thu, 02 April 2009 at 11:29 AM

 Tire tread is a huge memory hog. I've had the best luck using a UV normal map and Inagoni's Deeper to create believable tread without the file size overhead.






bwtr posted Thu, 02 April 2009 at 7:59 PM

Mark
Any chance of a small tute detailing that proceedure--for a tyre tread--- via Deeper please.
After all this time I really am not with UVs and normal mapping yet.

Brian
(The side tracking question answerer!)

bwtr