Black reflections of lights on low glossiness surfaces

Corona Corona for 3ds Max Issues
1

Now this is interesting,
I have a very simple wall material there.
If I use 1.0 glossiness you can see that spotlights reflect.
But if I use a lower value like 0.66 etc you can see a dark blurred reflection instead of a bright one.

Am I missing something or is this a bug?

weird3.jpg
weird3.jpg1512×527 230 KB

2

I guess this should be move to the bug reports section, looks really wrong. Also, rename the thread to something that catches devs’ attention :wink:

3

yea, something wrong about lights I think

weird6.jpg
weird6.jpg980×323 106 KB

4

What version you’re using? Can you attach simplified scene where this behaviour still reproducible?

5

Also, does this also happen when visibility for the light is enabled?

6

version is 1.5 hotfix 1, I attached simplified max file with that room, I think textures don’t matter so I didn’t include them.

when I select “visible directly” it’s still a black reflection in the middle.
forum_max.max (1.33 MB)

7

Is Occlude other lights is turned on?

8

@nekrobul

no, it’s always off if I use as a hidden light

9

I remember having this a while ago, as far as I remember that dark reflection was only visible with a glossiness between 0,6-0,9. Had no time to dig deeper, it´s a bug imho. Attached the questionable area, you can see the lights floating in the air used to lighten the logowall as dark reflection. No change in the visibility group could prevent them from appearing. It´s as if the reflection sees a dark light geometry even when “Visible in reflections” is turned off.

Good Luck

Edit: attached minimized scene showing the effect

glossy_light_reflection.jpg
glossy_light_reflection.jpg882×353 99.3 KB

dark_light_reflect_Max2016.7z (135 KB)

10

Ok, renaming and moving this to bug report board.

11

This looks like the old “reflection of a refraction” problem, only without the refraction part…
Aleeriza - are you sure that you are using the newest version of Corona? Can you re-install it just to be sure?

12

@maru

this morning I downloaded, reinstalled (1.5 hotfix 1) again, unfortunately the bug still exists. It’s out there.. Waiting for us.. waiting.. the deadline..

13

That’s strange, but I have problem with reproducing this, even in the submitted scenes. That’s why I have some questions:

  1. What kind of camera are you using? (or “is this also happening without using vray camera”)
  2. Is this also happening if camera clipping is disabled?
  3. Is this happening only if PBR mode in material’s advanced settings is disabled or only if it’s enabled?

Ok, works in Frood’s scene. Ondra has to check it. The effect only appears if “visible in reflections” is unchecked.

14

with hotfix 2 :

Screenshot_10.jpg
Screenshot_10.jpg625×327 98.1 KB

15

It seems that the something similar happens in situation when sunlight goes through CoronaLightMtl, “emit light” unchecked.
Got this round shadow on glossy surface..

circle_shadow.jpg
circle_shadow.jpg725×544 55.1 KB

circle_shadow.max (264 KB)

16

Well, now we can only wait for Ondra’s intervention.

17

Is there something new about this bug?
Was it submitted to mantis?

18

this will be probably a case of “2 fakes not working well together”… let me take a look when I get to debugging :wink:

19

Ok, thank you! :smiley:

20

Up.
(as it was buried somehow) :smiley: