Author Topic: Lightmix bug - Light jumps to enviroment when uncheck "occlude other lights"  (Read 8442 times)

2017-03-29, 15:45:50

DotDesignStudio

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Hello,

When a Corona Light has unchecked "occlude other lights" it is visible in lightselect channel for environment only. When it lights up an object with translucency it gets weird, because it does not match separate channel with only this light. Like only secondary bounce ends up in environment channel.

Corona 1.5 hf2, 3ds max 2016, win 7

2017-03-31, 18:47:42
Reply #1

DotDesignStudio

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Also when the light or light material does not cast shadow it is added to environment light select channel. Also i can not exclude object with light material from specific light, so it cast shadows....

2017-04-02, 14:04:26
Reply #2

PROH

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Hi. If I understand it correct, this is part of the the same problem as I have had recently. There is only a small difference in my setup vs. DotDesigns: In my case I've made a dedicated "Lightselect_Environment" RE, where I believe DotDesign are refering to the automatically generated "Rest (unassigned" RE) when he says "Lightselect Environment Channel.

The problem I've found is, that when "visible directly" is checked in a Corona light, the directly visible light is part of the "Rest" RE and NOT the Lightselect RE for that light (pic. 1).
However when making the same setup for an object with Corona Light Mtl applied to it, the directly visible light is part of the Lightselect RE for the object/light - just as expected (pic. 2).
But - If "Emit Light" is turned off in the Corona Light Mtl, then the directly visible light suddenly is part of the "Rest" RE (pic. 3).

This behavior makes it difficult/impossible to turn off a single light in the lightmixer, in situations where the light is seen directly.

Hope my explanation makes sense. I've attached 3 pictures to make it understandable.

Regards

NB - the test is made with 3dsMaxDesign2014 and Corona 1.6 DB Mar 27

2017-04-11, 15:13:05
Reply #3

PROH

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Hi. Just checked with 1.6 RC2 and got the same result. Could somebody please tell if this is a bug, or "expected behavior" (sure looks like a bug to me).

Regards

2017-04-11, 15:22:10
Reply #4

Ondra

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this is currently working as expected - non-explicit light sources cannot be lightmixed. I am currently not sure if this will be fixable
Rendering is magic.How to get minidumps for crashed/frozen 3ds Max | Sorry for short replies, brief responses = more time to develop Corona ;)

2017-04-11, 16:11:00
Reply #5

PROH

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Hi Ondra. Thanks for your answer. But why does a light and a ligh-mtl not behave in the same way then? Why is it "only" the direct visible light coming from a corona light that is "non-explicit"?

2017-04-11, 16:15:56
Reply #6

maru

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I am not sure what are the technical limitations, but I also think that control over self illumination and lightmtl with emit light off would be useful. Or if not that, then at least possibility to group a light with self-illuminated object, and controlling them together. This would make it possible to control lights which have an invisible light emitter and a "glowing" object such as bulb filament, and it is a common workflow. Imagine bloom and glare, or changing light color.
(turned out to be offtop, sorry)
« Last Edit: 2017-04-13, 13:31:41 by maru »
Marcin Miodek | chaos-corona.com
3D Support Team Lead - Corona | contact us

2017-04-11, 16:16:20
Reply #7

Ondra

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corona light does not have the button for emit light exposed, so you cannot replicate the situation 1:1 in both. We are keeping them separate for slightly different use cases - for example it is unlikely that you will ever create backplate using COronaLight
Rendering is magic.How to get minidumps for crashed/frozen 3ds Max | Sorry for short replies, brief responses = more time to develop Corona ;)

2017-04-11, 16:23:44
Reply #8

PROH

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Just to clearify: I'm asking about why a Corona light doesn't act the same way in the lightmixer as a light-mtl with "Emit" ON. I would expect them both to behave as the light-mtl does in my example posted above.

Regards

2017-04-11, 16:29:54
Reply #9

Ondra

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ok, i looked at the images again and it seems like a bug, I cannot reproduce it, can you send me the scene?
Rendering is magic.How to get minidumps for crashed/frozen 3ds Max | Sorry for short replies, brief responses = more time to develop Corona ;)

2017-04-11, 16:52:50
Reply #10

PROH

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Thanks. I'll send the scene (simplyfied) ASAP - tonight or tomorrow.

Regards

2017-04-11, 17:20:24
Reply #11

PROH

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Hi. Here's the scene. Turn Lights/Light-Mtl objects ON/OFF in layermaneger.

Made in 3dsMaxDesign2014 with 1.6db 2017-03-27 and tested in RC2 with similar result.

Hope it helps

2017-04-13, 10:11:33
Reply #12

DotDesignStudio

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When a LightMtl has opacity, then this light is in the Enviroment Lightselect.
Please open attached scene, start Interactive Rendering, and turn on and off opacity in "SWITCH OPACITY PLEASE" material.

2017-04-13, 13:39:29
Reply #13

maru

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I think we might have two separate issues here:

1) PROH - difference in LightMix between a Corona Light and an object with CoronaLightMtl applied
-it seems that there is a visible light shape of the Corona Light in the "reset" layer only if that Corona Light has IES enabled - can you confirm this, and correct me if I am wrong?

2) DotDesignStudio - I am looking into this right now...
-There is indeed something strange going on with light opacity and environment layer of LightMix. This can be observed in the scene submitted by DotDesignStudio. I am also attaching my simple test, where switching opacity on/off and playing with LightMix produces strange results (for example part of the teapot being invisible).
« Last Edit: 2017-04-13, 13:50:57 by maru »
Marcin Miodek | chaos-corona.com
3D Support Team Lead - Corona | contact us

2017-04-13, 15:33:28
Reply #14

PROH

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@Maru - Yes, I can confirm that unchecking IES makes Corona lights behave as expected (in RC3). I actually thought that I had tried this already (earlier DB version), but....

Hope this will be fixed :)