Excluding geometry from GI

[nickb]

Can anybody explain how have geometry in the scene, like a skydome with sky texture map, in Vray (to be visible to reflections and not the camera) without it blocking the GI from the environment?

With traditional scanline renderer i usually use a half sphere with a sky texture mapped to act as the reflections in glazing for example. I would usually exclue this from advanced lighting and stop it from casting and recieving shadows. I have tried this in Vray (switching generate and recieve GI off) but when the skydome is in the scene, the scene still goes dark.

I would prefer to use this method over HDRI maps as it gives me more control

Thanks

[zapcat]

Right click the geometry in your viewport, select properties, and untick visible to camera.

[nickb]

Thanks, ive tried this, but the this still blocks the GI as the object is still in the scene

[dose]

Hi there Nick, nice beard.

Have you tried a vray material wrapper set to not send or recieve GI?

Hope this helps!

Good luck.

D

[nickb]

Thanks Donut - tried that too with no joy

[suurland]

I only know one way which is to set the properties to not "visible to reflections/refractions" but that only works sometimes since you might want the object to show up in reflections.

My big wish is a "DON'T BLOCK GI" in the properties or material or something.

/Thomas

[egz]

1.45.70 has a "visible to GI" checkbox in the object properties. This does what you want.

[dusan]

Can you explain what do you mean by "I would prefer to use this method over HDRI maps as it gives me more control", it sounds very complicated to me and i doubt its more efficient than using hdri or just an enviroment mapped bitmap.


Maybe we can give you a few tips on using hdri to replace that old technique.

[Da_elf]

the "visable to GI" option is a great addition.

[Ben Ando]

The other way I've done this is by calculating and then saving the Imap with the skydome hidden. Then unhide the skydome and load the saved Imap. Make sure you turn off generate and receive GI on the skydome though, otherwise the render can crawl.

A bit of a work around I know but we haven't got to 1.45.70 yet. The "visible to GI" option sounds great!

Ben

[nickb]

Thanks everyone for all your help - hiding the skydome seems to be the solution for me, it seems so obvious now! looking forward to using 'visible to GI' option

Can you explain what do you mean by "I would prefer to use this method over HDRI maps as it gives me more control", it sounds very complicated to me and i doubt its more efficient than using hdri or just an enviroment mapped bitmap.


Maybe we can give you a few tips on using hdri to replace that old technique.

Another main reason for using skydomes is we already have some good hemispherical skydome maps which wont work as HDRI or spherical env maps as they are only 18 degrees not 360, also i know what i'm doing with them and dont really with hdri - need some practice!