Lights through glass displaying black

[Jpjapers]

Havent seen this in a few versions. Lights showing through glass as black discs?
max 2018, corona 3 with standard glass shader+ absorbtion colour.

[dzintas]

Usually this happens when you uncheck "visible in refractions" checkbox.

[Jpjapers]

Usually this happens when you uncheck "visible in refractions" checkbox.

Yes but in this instance that box is checked.

[alexyork]

I've also had this lately using a recent v4 DB although can't compare in v3/v2 for now. same kind of set up. super simple thick glass screen with a simple disc corona light visible through it - renders black. when you don't look through the glass it renders white. visible to refraction/reflection + visible in render all turned on, incl. prevent black appearance.

[Jpjapers]

I've also had this lately using a recent v4 DB although can't compare in v3/v2 for now. same kind of set up. super simple thick glass screen with a simple disc corona light visible through it - renders black. when you don't look through the glass it renders white. visible to refraction/reflection + visible in render all turned on, incl. prevent black appearance.

Yeah same exact setup it seems. I havent tried any dailies.
Ill experiment and see if i can find any cause.

[maru]

Already reported.
(internal id=223075528)

[sprayer]

In v5 still this problem exist
Is there any workaround? I can't turning off refraction for frosted glass =(

it seams this happens for ies light

[maru]

The workaround is to use two separate objects for lights:
1. The visible part, which will be visible directly, in reflections, in refractions - it does not emit light, but it is visible. Example: LightMtl with "emit light" off; rayswitch
2. The invisible part, which casts light into the scene - e.g. a Corona Light set to fully invisible

The issue here is that the "prevent black" option only works for direct visibility (not for reflections and refractions). We know about it and want to provide a fix as soon as possible.

[sprayer]

The workaround is to use two separate objects for lights:
1. The visible part, which will be visible directly, in reflections, in refractions - it does not emit light, but it is visible. Example: LightMtl with "emit light" off; rayswitch
2. The invisible part, which casts light into the scene - e.g. a Corona Light set to fully invisible

The issue here is that the "prevent black" option only works for direct visibility (not for reflections and refractions). We know about it and want to provide a fix as soon as possible.

Thank you i will follow in that way.

[jasonvdp]

Has this been resolved already? I am still having the problem with Corona 6.

[TomG]

No, it is actually a very very complex issue to resolve, so resolution is not on the cards, in the near future at least (you can check the roadmap to see what is on the cards https://trello.com/b/EfPE4kPx/corona-tentative-road-map-3ds-max ).

[Coco_74]

This still seems to be an issue, when is this going to be fixed?

[TomG]

There is no time frame for a fix, sorry.