CGTalk - does scale of scene affect lights?

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EyeAmYou

05-23-2006, 09:55 PM

ok, i know this is probably a fairly stupid question, but i'm just getting into lighting. so anyways. i needed to know if the scale of the entire scene affects how your lights react to your objects? for instance, i've been doing lighting tests with a scene that i had scaled everything down to fit within maya's default grid. there's no particular reason that i have everything scaled down like that. it's just something i like to do. but today i had gotten a rigged version of one of the characters who cannot be scaled. therefore i had to scale up the rest of the scene including my lights, but now the lights are reacting slightly differently, and i just wanted to be 100% sure that the scale of the scene affects the lights in maya. thanks.

harryhood

05-23-2006, 11:26 PM

You should always model to scale. I don't know exact details in maya but depending on what kind of lights you use, yes, scale will affect lighting, especally if you rescale after setting up your lights.

MikeBracken

05-23-2006, 11:49 PM

Imagine you model a room and pay no attention to scale. If the actual dimentions of the room
are 50 meters x 30 meters and you use a 60 watt light, you will not be able to properly light it.
It can be like trying to light a football stadium with a couple of 100 watt bulbs. ALWAYS model
to scale. It makes everything easier.

CaptainObvious

05-24-2006, 01:20 AM

You should always, ALWAYS, model to scale. Light intensities/falloffs become easier to work with, and camera settings (fStop and whatnot) are sometimes incorrect if you change the scale.

h2o

05-24-2006, 05:34 AM

Scale the scene or camera will affect decay lights in Maya.

Change the scene scale after finished lighting..... it's a nightmare of a lighter :eek:

Ministry

06-04-2006, 06:15 AM

hi, I suggest u always work with scale. Why take chances. .?

tel

06-04-2006, 04:49 PM

Hi guys,

now im work in architetural project and i receive a scene in milimeters, so when i finish the modeling the scene is soooo big. For lights is really cool but when start ajustment of final Gathering and GI the problems come.

First. the Fallof distance... i use now 90 for start and 800 for end. Dude.. the render take soo long, im mean, five hours.

Global Ilumination the value is something like 70000000.00 :eek: So if i have area lights, sun light (wich i could do it because give me erros) , the render is so slow.

Other question, if i put a directional light the render still be five hours for calculate, but is just a white scene :sad: if i conect a infinite light shader at the directional, keep the same white scene.

can you guys help me?

I dont open a new topic because i think its almost the same problem..scale scene.

EyeAmYou - dont be mad ok?

jeremybirn

06-05-2006, 07:22 PM

Other question, if i put a directional light the render still be five hours for calculate, but is just a white scene :sad: if i conect a infinite light shader at the directional, keep the same white scene.

A directional light doesn't really start at a light position and decay with distance, so you usually need much less photon intensity. Like sometimes just 2 or 3 instead of millions. Run some tests (with fewer photons) to get the intensity right for a directional light instead of using the photon intensity you'd use with other light types.

-jeremy

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