hi all,

i'm new to houdini and have some questions about the houdini area light

1. why do area lights cast light in all directions and not just the way they're facing?

2. is there a way to fix this without using blocking geometry (such as a plane set to render as phantom)?

Hi ,
Area lights will scatter light by their very nature. Have you tried using attenuation ? .Maybe post up a scene of what you are tying to light.


Rob

hi

so here's some tests, the first image is rendered Vray for XSI
[divshare.com]
and a similar scene with mantra….
[divshare.com]
[divshare.com]

jason

It's actually possible to do this in Houdini for mantra too (though maybe not so intuitive).

The light object is just a collection of properties. The properties are used to define the shader on the light.

However, it's possible to assign your own shader to the light.

In the example .hip file, I simply put down an ASAD light shader in SHOPs, turned on cone lighting and dragged it onto the light's geometry in the viewport (adding the shader parameter). Of course, I should have re-arranged the parameters on the light object, but I was lazy.

ok, nice thx Mark
it would be nice to get it working like that out of the box!
i'm still unsure about the light attenuation in PBR, this thread:
http://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&t=14015 [sidefx.com]
is it correct that using physically correct attenuation creates so much noise?

thx
jason

thanks mark, much appreciated

is there perhaps a node for creating visibility options such as visible in render / reflections / refractions?