View Full Version : Ambience from a light?

02-27-2006, 11:06 PM
Hi, how i can use a "ambience" from a light in XSI (i need it for use with falloff from the light), is for illuminating (without GI or FG) like in this tutorial (http://www.cgarchitect.com/resources/tutorials/smoke3d/tutorial3.asp) (look the first step).

Thanks and sorry for my poor english :thumbsup:

02-27-2006, 11:15 PM
When I have done things like this I turn off specular and shadows and then use falloff on the light (squared etc.). You could use a point light for this instead of the max omni light.

02-27-2006, 11:25 PM
Hello, thanks for the aid.
What happens when I do that it's that the objects that are affected by that light have a small shaded that accuses the position of the filling light. With the ambience this shading doesn't exist.

Thanks in advance.

02-28-2006, 12:19 AM
Post a screen shot show we can see exactly what is wrong.

02-28-2006, 01:27 AM
Ok, here is 2 render (XSI and 3dsmax), both with a point light (omni in 3dsmax) in the center of room and with lineal falloff. I want have a ambiance light from the point light just like in the render of 3dsmax.


Thanks and sorry (again) for my english.

02-28-2006, 03:58 AM
Your english is fine really so no problems there and besides most of the world doesn't speak it. I'm the one who should be saying sorry.

Anyway- I see- you're still getting a diffuse look- which is problematic for you on the objects mainly. I think that for some of it you'll have to use the render tree- or selectively use your lights. I'm not certain that XSI has a preset like that for a light.

I'll look into it...

02-28-2006, 05:48 AM
No, XSI doesn't have ambient light like in some other apps (max etc.). I miss it too sometimes.

You could re-create that effect with Render Tree using gradients, nulls and some expressions but its not very effective when you have lots of objects.

02-28-2006, 04:21 PM
ive been asking this myself since i switched to xsi . I realy miss some of maxs light types, and this one the most.
ssalo how would you go about faking this on the render tree. Just curiosity.

02-28-2006, 04:44 PM
Ok, thanks anyway for the help.
Maybe with a shader (3rdparty) for light? i will continue looking for a solution, if somebody find one way please post it here.

Thanks :thumbsup:

02-28-2006, 05:29 PM
Well these aren't the best examples since I'm not as familar with this kind of lighting in XSI, but you could just use area lights without shadows (the second one uses colored shadows) to get a similar effect that in some ways can prove more flexable. And just like everything else there is plenty of control over the area lights in XSI.

It's funny I haven't used MAX since 3.x, but streching omni lights was one thing I used a lot- and still miss.

The omni light effect in the tutorial looks more like a distance based gradient that uses the ambient light color. You might be able to setup a null and a distant gradeint along with a constant surface that mixes with another shading model. But unless you want to do a pass of some kind this could be a headache to put on every surface etc.

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