I like to disable specular component from a light base on per object or shader without separate lighting setup. Is it possible to set this up on per object basis?

Does something like light selection(mask) exists on Physically Based Specular VOP or Diffuse VOP shading component inside shader??

Thank you

Yes , even you can use different Specular color for different objects with same shader !

Just add a custom attribute for your objects , then import this attribute in your shader and multiply it with final specular ! 8)

I made a simple project about this for you :wink:

thank you Joker, overwriting spec geometry attribute will not filter per lighting component, sorry I didn't make it clear. ops:

There are few lights illuminate the same object. I like to switch off specular but still receive diffuse contribution from one of those lights, and other lights illuminate as normal. I used to setup extra light only for this object with specular lighting off, but it's messy when scene gets complex. Wonder if there is something on object or geometry level that combine “light mask” on object node and “light contributions” on light node does per light contribution component filtering.

For shader, I just found ‘lightmask’ does per shading component support.
http://www.sidefx.com/docs/houdini13.0/vex/contexts/shading_contexts#lightmask [sidefx.com]

I setup a sphere scene with 2 lights(light1, light2) and following code on inlineVop connect to surfaceOutputVOP of a material shader builder.

vector nn=normalize(N);
$f = diffuse(nn, .5, “lightmask”, “light1”) * 2;


Both light illuminate as without “lightmask”, I couldn't get it work.

I used to setup extra light only for this object with specular lighting off

Did you try "Non Specular Light" option in the Light node !?
Of course you should add this in the Edit Parameter interface .

yes, that's what I did before H13. H13 new lighting contribution works like a charm

any idea how the ‘lightmask’ label works??

anyway, thank you for your help