Star Ceilings

[sainty]

Good afternoon Twilighters,

I am searching for a couple of effects, and textures.

Fletch , you helped me out enormously a few months ago with a perforated metal template that I used to great effect, I wonder if you could help me out with any short cuts to achieving the look of a Fibre Optic Star ceiling.
My company has used high resolution rendering companies to simulate this,(see image 1)but I wondered if it was possible to do it in Twilight?
I have tried creating a circular ceiling panel, and laboriously cutting 5 mm holes through it then copying a dozen or so, moving them, and pasting making a random star field.Then I placed a high powered emitter above the ceiling (3500 power) but there is little noticeable effect.Maybe more power?
Maybe I should be placing light points rather than trying to pass light through a hole, but I would need 200- 300 to achieve this, so I was wondering how the pro's did it?

You can see the projector beam in this rendering too, that would be very handy to know how to achieve.

Finally, I have had a good hunt around for a good Suede material, there are plenty of leathers on CG Textures, but no suede. Any pointers?

Splendid stuff.

Sainty

[flipya]

Have you tried using small emitters instead of actually cutting holes in the dome? I guess they would have to be triangular to render fast enough, but that shouldn't really be an issue on that scale.
About the projectorbeam, I suppose you could render it, but personally I'd just add it in photoshop.

[Fletch]

Hi Sainty,

Star Ceiling...
I would go one of two ways...
Paint the inside of the dome with the texture you want to use that looks like the star ceiling and set it to be an emitter.
or project the image onto the ceiling with an invisible spotlight. (this should be the first thing to try maybe. anything black in the image will not project light... so make a black rectangular image for your projector image, with a circle cut into it containing your sky image... if you know what I mean.

for the projector beam... post pro is fastest.
or this is perfect...
http://twilightrender.com/phpBB3/viewto ... =26&t=1375

[Pilou]

A pivate movie room!

[sainty]

Have you tried using small emitters instead of actually cutting holes in the dome? I guess they would have to be triangular to render fast enough, but that shouldn't really be an issue on that scale.
About the projectorbeam, I suppose you could render it, but personally I'd just add it in photoshop.

That worked great, thanks Flipya, It didn't take long to create some 10mm, 8mm and 5 mm squares,make each size a component, make them emitters, copy them at random, rotate a few groups of them for a more natural look, then render at 2000 w.
I guess I could also alter the light output for each different size... Marvelous.
I now have a large star ceiling I can drop into any drawing when I need it.
I will post a finished picture, and the SKP file when I have sorted out the projector beam.

[Fletch]

If you are using the emitter template in Twilight, it will emit light wattage per square meter... so tiny stars will emit very little light.

This method of representing the stars is the best way to go, but likely necessitates using progressive rendering... as each start represents 1 light. Anything more than 10-15 lights in non-progressive renderings is considered "a lot" of lights.

This is not to say these methods can't handle thousands of lights, they can, it requires using lower render settings with many lights to avoid long render times or running out of RAM.

[sainty]

If you are using the emitter template in Twilight, it will emit light wattage per square meter... so tiny stars will emit very little light.

This method of representing the stars is the best way to go, but likely necessitates using progressive rendering... as each start represents 1 light. Anything more than 10-15 lights in non-progressive renderings is considered "a lot" of lights.

This is not to say these methods can't handle thousands of lights, they can, it requires using lower render settings with many lights to avoid long render times or running out of RAM.

Thanks Fletch,

I reckon I have around 200 small emitter points in this image. The emitter was set at 2000 w on the 100 watt normal setting.
It will be quite adequate for these preliminary renders before I hand the model over to the professionals.
It really has made my design procedure more enjoyable having some control over the final look.

One more thing, what's the procedure for imitating the projector beam in PS? Is there a special setting or mask I have to use to get that 'smokey' look?

[Fletch]

what was I thinking... just simply change the emitter material for the stars into "Fake" emitter in the emit template emitter "type" pulldown. renders instantaneously and you can render with any setting. don't know why I didn't think that before.


Projector light faking: (free photoshop plugin.) or use the method I linked above... looks fantastic.
http://amicoperry.altervista.org/luce/index.html

http://www.tutorialwiz.com/rayoflight/
http://www.kerkythea.net/phpBB2/viewtop ... 6667#66667

[sainty]

what was I thinking... just simply change the emitter material for the stars into "Fake" emitter in the emit template emitter "type" pulldown. renders instantaneously and you can render with any setting. don't know why I didn't think that before.


Projector light faking: (free photoshop plugin.) or use the method I linked above... looks fantastic.
http://amicoperry.altervista.org/luce/index.html

http://www.tutorialwiz.com/rayoflight/
http://www.kerkythea.net/phpBB2/viewtop ... 6667#66667

HA! Thanks Fletch, it worked a treat.
How does the fake emitter setting differ from the normal setting? It did render a little more quickly, but I don't understand why?

[Fletch]

it renders white, does not emit light. so now it's not calculating any light, shadows, etc.