Karma geo-lights AOV splited by LPE tag issue

[Sinbad]

Hello, I've got a question because I'm getting stuck on something while figuring out karma: I import a geo from SOP and with a render_geometry_settings node I set it to treat as light with a specific LPE to make it a geo-light, except that when I get to karma to make my aovs and split them by LPE, I realise that Karma only generates AOVs for "classic" lights (dome-light) and none for my geolights - here are two screenshots, if anyone has a solution or ideas I'd love to hear them, as I can't find much online at the moment on the subject of geolight LPE in karma.

[toketronic]

Hey

 

I'm stuck the same place did you find a way? Or perhaps another solution?

 

Thanks

[besit]

Trying to solve the same thing. Any updates?

[pabushka]

HI basically you'll need to create the AOV yourself if you want to have a geometry light AOV.

1. add a new var (found at the bottom of the karma render settings )

2. give it a name so you can identify the AOV

3. in "Source Name" you'll need to write the "C.*<L.'LPE Tag Name'>"

from what I can tell of what this means is:

C = color (Beauty AOV)

L = light

'' = string value

. = It's most likely so the machine knows where the names stops

<> = indicate the value (I think...)

* = I have no idea why it's there but it's most likely to the the computer that we want B (Light LPE tag) within A (Beauty AOV).

I know we can use this with other AOVs liike combined diffuse. A good way to learn how to write for different AOVs is to create a light, give it a LPE tag, in karma render settings activate the AOV you want (Beauty, combined diffuse), check split LPE tags and look in geometry spreadsheet "Render>Products>Vars>"the light you're looking for" and it should show how to write your own AOVs.

Here are links to houdini documentations.

https://www.sidefx.com/docs/houdini/nodes/lop/karmastandardrendervars.html

https://www.sidefx.com/docs/houdini/nodes/vop/kma_material_properties.html

https://www.sidefx.com/docs/houdini/nodes/lop/rendergeometrysettings.html

https://www.sidefx.com/docs/houdini/solaris/kug/materials.html#emissive

And a video of a kind gentleman....

 

[TastySoul]

You can add an LPE tag node right before karma. Add your geometry lights to the list by clicking on teddy bear icon in the middle and give them tags.

Then you can include these geometry lights in karma render settings and they should show up for you in the render primitive list. Earlier I gave my sky lights an 'Untagged_Lights' tag so they wont have layer, if you need them just give them a tag or remove the 'Omit LPE Tags checkbox'

Did this for my lightning which is emissive mesh treated as light source

 

 

 

Edited yesterday at 03:48 PM by TastySoul