Looping Through Lights?

[sibarrick]

Hi,

Really interesting talk at the Houdini meeting by the guy from the Orphanage, I was particularly interested to hear that they used a sop method to do their sub surface scattering stuff for the snow.

Sounds familiar I thought , anyway it got me thinking perhaps there is still some mileage in that old hack but perhaps it could be improved. First off I thought I could now update it to use point clouds which would make it way quicker, then I thought maybe in the HDK I could encapsulate the whole thing in one sop rather than having to have one for each light. To do this I need to build an illuminance loop that would work in a sop environment.

So the question is, would this be possible? I had a really quick scan through doxygen but couldn't see anything obvious that would let you do such a thing, so any pointers would be very useful. Many thanks in advance.

[Wolfwood]

Hi,

Really interesting talk at the Houdini meeting by the guy from the Orphanage, I was particularly interested to hear that they used a sop method to do their sub surface scattering stuff for the snow.

Sounds familiar I thought  , anyway it got me thinking perhaps there is still some mileage in that old hack but perhaps it could be improved. First off I thought I could now update it to use point clouds which would make it way quicker, then I thought maybe in the HDK I could encapsulate the whole thing in one sop rather than having to have one for each light. To do this I need to build an illuminance loop that would work in a sop environment.

So the question is, would this be possible? I had a really quick scan through doxygen but couldn't see anything obvious that would let you do such a thing, so any pointers would be very useful. Many thanks in advance.

20153[/snapback]

Take a look at this thread...OP_Operator::getActiveNode() might help

http://odforce.net/forum/index.php?showtopic=2814

[MADjestic]

Hi,

Really interesting talk at the Houdini meeting by the guy from the Orphanage, I was particularly interested to hear that they used a sop method to do their sub surface scattering stuff for the snow.

Sounds familiar I thought

[sibarrick]

Could you eleborate on this a bit more, please?  Sounds intriguing, but I don't think I got the idea of this hack.

20172[/snapback]

Here's a link to the original otls

Fake SSS

Basically it's a similiar idea to the ambient occlusion stuff you are currently doing. You pre bake the SSS into the geometry so that the render is really quick, all the shader needs to do is add the SSS attribute from the geometry straight into the render. The down side at the moment is that in VEX I have no way to loop through all the lights so you have to have one node per light, that then takes a little time to set up, and it's very flexible if you need to add or remove lights from the scene. It's a hack because it can only work at the level of detail of your input mesh, but for for subtle effects or ones that are quite smooth it's more than acceptable.

I talked to George about this today and it's definately doable. Basically I could make an illuminance loop for sops. This would also open the door to baking any lighting info you want.