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View Full Version : HDRI Lighting/Diffuse values...on and on.



Grantw
09-18-2003, 05:05 PM
This is driving me crazy. I have read heeps of material on hdri lighting and light probes and Image World.

I have a model of a compact flourescent light bulb I am trying to light with a probe. The only thing that seems to light is the screw portion at the bottom. Because I have some reflectivity in it. The plastic base is black although it's really white from a diffuse color point of view. The glass portion which is also white and glossy comes out black as well.

All lights are off/ambient off/GI on.
I have cranked the value up to 5000% and the refelctive parts increase, but the diffuse areas stay black. The probe appears to be acting as an environment reflection only.

I thought the idea of a light probe was to cast its values down onto the object. Diffuse values would light with some color bias from the probe. Refective areas would pick up a nice reflection from the probe. And it would cast a nice shadow on the surface.

The tutorials make it sound like you load the probe in the Image World plug in turn GI on and then hit f9 and have a party.

No party here!!
Help?

Mylenium
09-18-2003, 11:37 PM
You will need some "real" light in your scene to initialze radiosity calculations properly (it forces LW to start emitting rays). This can be as little as 0.01%. Never turn off your ambient entirely. this will ruin any radiosity.

Mylenium

omeone
09-19-2003, 02:02 AM
Ambient lights get treated / used very differently when radiosity is turned on, it actually enhances the the light and reduces the need for bounces, I've have good results with about 40% ambient, and even 75% on one occasion.

Grantw
09-19-2003, 10:15 AM
Thanks I'll give that a try.
I guess I'm confused by the tutorials. You would think that someting this important would be mentioned.

I thought that the light probe in the image world plug-in was generating all the light required.