a long light bar -> render time

[algato]

Hello,

in my current project I have a 32 meter long light bar in a corridor.

Now I ask for your opinions: what is better for the rendering time, when I draw the light bar as a one long Vray Light, or rather divided into sections? If divided, then what length of the sections would be optimal for Vray?




Kind regards
Alex

[jacksc02]

one long light bar will be fine

[Mnietek2707]

What about benefits from probabilistic lights?
Maybe it would be better to make, for example, 32 lights?

[Vizioen]

Hello,

in my current project I have a 32 meter long light bar in a corridor.

Now I ask for your opinions: what is better for the rendering time, when I draw the light bar as a one long Vray Light, or rather divided into sections? If divided, then what length of the sections would be optimal for Vray?


[ATTACH=CONFIG]29058[/ATTACH]

Kind regards
Alex

I've done similar projects and always use 1 long vray light. Together with a plane with a vray light mat. And the vray light on invisible.

[Macker]

for LED's where you want to see individual spots, what i've done in the past (quite successfully) is use a spline with a sweep modifier & mapping coordinates, and then apply a vray material with self illumination and put a gradient in the self illumination slot that ranges from black to the colour of your light. Hope this makes sense as it works well...

[^Lele^]

There's no beating keeping number of light fixtures low: even probabilistic would only kick in after 16 by default. and then STILL sample those 16 each time, while the single, long light fixture would always only be evaluated the once per sample.
This is intrinsic in the lighting loop any raytracer has to go through, so it's not circumstantial to a specific scene (although one may want to test it out, just to be sure.).
So as Chris said, one long vray light is best, and with the difference in performance compared to multiple lights, you're also quite free to have it textured if you so wished.

[^Lele^]

Actually, i am finding that V-Ray is quite efficient (even without the prob. lights active!) with multiple lights, so by all means, do try both approaches!