CoronaLight with IES Visibility issue

[borisquezadaa]

A CoronaLigth with IES file  shows black (all types sphere rectangle disk cilinder) when Visible directly on and its necessary to unthick "occlude other ligths" or "visible directly" to hide his geometry.
It could be useful in some cases to show the emitting geometry but black?.(that makes no sense).
Visible directly has no use it seems for light with IES?

[maru]

Is it visible when you are looking at the light perpendicularly? Maybe it's related with this: https://forum.corona-renderer.com/index.php/topic,2674.msg19710.html#msg19710

[borisquezadaa]

Not related to directionality issue. The base geometry of a CoronaLight turns black in render time the second you put an IES file to them.
Unless you unthick Visibility tab. (Directionality is 0 by the way).
At least it could be white (or better Textured!)... but black?.

Corona A7.1 by the way.

[maru]

Hmm. Daily build Oct 14 2014 here. Here is my ies light. Did you try with a different ies file?

[borisquezadaa]

Crap. You where right. Its IES related. Tested on other Ies file and works fine.
Atacched offending IES just for forensics.
Also noted that sometimes not entirely black (check attached). Units related?.

Thanks Maru.

[Ondra]

All of this is caused by the same thing - if IES is directional, and you look at it off-direction, it will show black, because no energy is emitted to the camera. Think about it - replace the camera with a wall - it would be black - so why should camera see any light?

[peterguthrie]

just digging this up..

would it be possible to have a checkbox to make the light always visible regardless of where you are looking at the light from?

[peterguthrie]

high tech screen capture:

[FrostKiwi]

just digging this up..

would it be possible to have a checkbox to make the light always visible regardless of where you are looking at the light from?

Wouldn't make sense, as we are creating fakes in an otherwise physically based renderer.
Incase you didn't know: To achive this effect you put a RayswitcherMTL onto the light and Override Direct, Reflection and refraction slots with a light with 0 directionallity. What you get is a directional light, that you can see from any angle.

[peterguthrie]

in that case shouldnt an IES light always be invisible (like vray) as this is just going to cause issues.

[RobH2]

just digging this up..

would it be possible to have a checkbox to make the light always visible regardless of where you are looking at the light from?

Wouldn't make sense, as we are creating fakes in an otherwise physically based renderer.
Incase you didn't know: To achive this effect you put a RayswitcherMTL onto the light and Override Direct, Reflection and refraction slots with a light with 0 directionallity. What you get is a directional light, that you can see from any angle.

Can you explain how to override the slots with a light? I'm new to Corona and can only see that I can replace them with a map or material. How do you replace the slots with a light?

[romullus]

For starters, this is applicable only to light material, but not to light object. Furthermore, it needs to be tested if working - IIRC Corona has some limitations when pluging LightMtl to RayswitchMtl.

[RobH2]

Thanks 'romullus'. I'm hoping 'peterguthrie' is still around with a little explanation about what he meant. I've been playing with it and just can't figure out what he did, especially since the light is an IES.