Question of light sources vs glow material

Hi all,
Would there be any differences
if i have a sky dome defined by a series of light sources ( with the
subtended FOV defined ) and one that is defined by a continuous glow
material ?

Of course the main task is for daylighting applications .

Cheers!

CW

Hi Chew Wei,

the difference is that there is no reasonable way to define the dome using light. Light is perfect for small intense sources. At every ray intersection, Radiance can efficiently test for light sources by sending a Ray to the source. This is more efficient then sending rays to random directions trying to find a source, which is the mechanism to treat a glow source. However, in the case of a sky dome, you would have to subdivide the source a lot or, if you have defined e.g. patches as light sources, you need to test a lot of these patches. For the typically rather smooth gradient of sky luminance this does not make sense in most cases compared to having a continous glow source with a gradient applied.

Cheers, Lars.

ยทยทยท

--
Dipl.-Ing. Architect Lars O. Grobe

On Jul 29, 2010, at 0:28, chang cw <solomoncw76@gmail.com> wrote:

Hi all,
Would there be any differences
if i have a sky dome defined by a series of light sources ( with the subtended FOV defined ) and one that is defined by a continuous glow material ?

Of course the main task is for daylighting applications .

Cheers!

CW

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