pauljs75 opened this issue on Feb 03, 2008 · 11 posts
pauljs75 posted Sun, 03 February 2008 at 7:30 PM
The problem is that I can't get lights to work when placed in position on my TerraSpeeder car. The light assemblies on the model consist of: reflectors, lenses, and headlight-bulbs (a modeled mesh - not the emitter kind). When I put a bulb (the emitter kind) in there, no light comes out. Drag the same bulb outside the car and it casts light on it. Also tried setting the "Anything Glows" light to the headlight-bulb mesh, and no luck there either. AFAIK the glass parts are set to Carrara's "Glass, Clear" shader.
In Bryce, I know I can position and scale a radial light - and it works. Apparently I'm not catching some minor detail on the Carrara side.
If anyone cares to debug, I could send the .car file. Or likewise if you think something might be wierd with the model, it happens to be one of my freebies in .obj format.
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dvlenk6 posted Sun, 03 February 2008 at 8:22 PM
You have to activate 'Light through trans.' in the render options; else the bulb's light will be blocked by the meshes.
EDIT - Anything Glows requires Global Illumination to actually emit light, AFAIK.
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GKDantas posted Sun, 03 February 2008 at 8:31 PM
Make the glass a separeted object and tell light to exclude it from the light list...
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Miss Nancy posted Sun, 03 February 2008 at 8:52 PM
pauljs75 posted Sun, 03 February 2008 at 11:09 PM
Miss Nancy: Is that using a bulb light? Or a spot light? (If that's a bulb, I'm suprised at how well the beam projects from something I made up on the fly.)
Is the car scaled automatically? (I used the auto-scale when importing, I figure size might also affect how lights are handled.)
GKDantas: I'll take note of excluding the glass from the light list.
dvlenk6: I'm pretty sure I had both "light through transparancy" boxes checked.
All: Thanks for the tips so far... Back to plugging at it...
Your friendly neighborhood Wings3D nut.
Also feel free to browse my freebies at ShareCG.
There might be something worth downloading.
pauljs75 posted Mon, 04 February 2008 at 12:12 AM
Now here's a thought... Anyone got an idea how to make the glow value for the headlight lens shader occur in spaced out thin horizontal lines? (I think somebody might know what I'm getting at.) Or perhaps it could better described as thin bars of a light color with thick bars of a dark color?
Your friendly neighborhood Wings3D nut.
Also feel free to browse my freebies at ShareCG.
There might be something worth downloading.
Miss Nancy posted Mon, 04 February 2008 at 12:08 PM
the spot has fx (e.g. light cone, sphere and flare) which means the headlight materials
don't need to glow. however, the c6pro light cone is not subject to realworld fx
(reflection by a curved surface, refraction by a lens), so it's gonna look fake unless
retouched in photoshop. use GI settings in general for more realistic renders.
pauljs75 posted Mon, 04 February 2008 at 12:52 PM
I managed to drag a different shader from the browser onto the tires... Black patina metal seems to work ok. (Most of the mats on my freebies are just placeholders for modeling purposes. They're supposed to be replaced.)
Not sure if Carrara 5 has the light cone thingy. Might play with some other stuff later to see how it picks up the light.
Also is there a way to slap a gradient on the light cone? To vary the intensity over the angle or something like that? That might help the realism.
As for the glow channel thought above, I was thinking of simulating those little molding marks seen on various lenses... Seems like that would have to be very subtle though, since a little bit of glow seems to do a lot to amplify any light hitting or shining through it.
Your friendly neighborhood Wings3D nut.
Also feel free to browse my freebies at ShareCG.
There might be something worth downloading.
Miss Nancy posted Mon, 04 February 2008 at 2:38 PM
skip the glow on the headlites - otherwise they're gonna be glowing all the time.
modern vehicles have got a molded polycarbonate "lens" which, due to the index of
refraction of the plastic, has got fresnel ridges molded into it. altho C6pro (and likely
c5 as well) cannot use refractive models to affect a lite cone in any realistic manner,
it's better to model those fresnel ridges into the headlamp cover (the "lens") IMVHO
rather than trying to use some texture/displacement method.
older headlamps use a standard tungsten filament, whilst newer ones appear blue,
as they're HID lamps which emit a great deal of UV lite, very hazardous to look at;
yet another example of a total lack of any governmental oversight in regard to
public safety.
in c6pro, select the spot, then open the "effects" tab and edit the light cone to get
falloff, add gels to simulate the fresnel ridges, add lensflare and glow (light sphere),
add turbulence et al. it takes time to understand all those things.
sfdex posted Thu, 07 February 2008 at 12:11 AM
C5Pro does have light cones. I can't speak for C5 standard, and I don't know which you're using. But light cones entered the Carrara blood stream back when it was still RayDream.
As for the horizontal lines in the lens shader, you can make a glow shader that uses a mixer, combining a light and dark color via the "wires" operator. You can select the number of horizontal or vertical lines independently, so you'd be able to make only horizontal lines appear.
As Miss Nancy said, it does take a while to learn your way around Carrara, but once you figure it out, it all does make sense!
:Dex
sfdex posted Thu, 07 February 2008 at 12:18 AM
