light tag "cast illumination"

[mesut]

hi,

in opposition to a light source that is built via an emission material that is attached to a geometry, a c4d-light and it's corresponding onctanelight-tag does not have the option "cast illumation".
why is that?

i really like using light sources only for reflection purposes without having them illuminate anything, so right now i can only do that by using geomtery and emission-material.
it would be great to have that option in a light-tag, too.

exporting a light-tag scene into standalone, i can see in the graph that this light-object is being translated into a geometry with a bright diffuse material attached to it. this material has either a blackbody- or a texture emission node to it, depending on what had been set up in the light-tag.
going futher down the graph one can see, that there of course also is the "cast illumination" flag and it is - obviously, since there is no other option set-able in the light-tag - activated.

i already went through all the .h, .res, .str - files of the "OctaneLightTag" and tried mimicing the "cast illumination"-stuff that i had found in the corresponding "BlackBodyEmission"-files... but boy... what a naive idea of mine to think a non-coder like me could simply add that option by himself. actually i did add that option, but it did: nothing

so, please. would you?

[aoktar]

Nice try:)

[mesut]

Nice try:)

sooooo.... is that a yes?

[aoktar]

No of course. Renderers are like science of physics and math rather than literature. You can't activate something not available.

[mesut]

...Renderers are like science of physics and math rather than literature. ...

well.. that's probably the reason, i don't get it. not that i would get literature, too...

... You can't activate something not available....

and here we've come to the point i don't get.
looking at the node graph there is a flag "cast illumination". just like "surface brightnes" and such, but those other ones have a representative within the c4d-octane-light-tag. if it's possible with those others, why not with this - also boolean - "cast illumination" too?

but, as i said i have no real clue, what i am talking about, as you can see in the screenshot expressed by the question marks.
no idea, where those nodes come from, or this "diffuse material" for that matter, why those nodes are being built during export, they don't do anything and are empty.

[aoktar]

Well. I thought that you wish add "stop shadow casting". I've checked again that and yes it's a parameter of emissions. But why do you want it? It's not about "casting shadows". It just stops the light casting.

[mesut]

Well. I've checked again that and yes it's a parameter of emissions. But why do you want it? It's not about "casting shadows". It just stops the light casting.

because i want to see the light source in the reflection of the silver ball, that you see in the screenshot, but don't want to add any light to the scene lighting.
that's the reason for this little test-scene.

in the real world, i do quite a lot product vis and agency-customers love to add "a little here, and a little more there" specially on shiny or metal-ish stuff.
having control over reflection spots on surfaces is essential.

until now, i helped myself by the workaround building a geometry and adding an emissive material to it, that would not "cast illumination".
now, that i saw that after the "translation" - or what you call the process - into the the node system, a cinema light ends up being a geometry, equipped just as if would have used the above mentioned workaround, i thought this could be possible.

so, please. if it's there, please open it up in c4d.
would save me quite some time.

thx.

[mesut]

just to close that topic - i am not sure to what conclusion this thread pointed.

is that something you can and if so will do?

[aoktar]

just to close that topic - i am not sure to what conclusion this thread pointed.

is that something you can and if so will do?

I wrote in list to spot that. Hard to say yes or no at the moment.

[mesut]

ok, thx.