Bug on Reflection Glossines + Object invisible to shadows

[Dionysios.TS]

hi all,

I think I found a bug when on the objects properties in a scene we turn off both receive and cast shadows options.
If you do this and in the scene the other objects use glossy materials, the produce a very weird and strange artifact on their surfaces.

I am including an image and 3ds max scene if you need it. (2017)

Basically, in this simple example, the sky object has off both shadows options and the ground plane a reflection with glossiness.
Look at the strange oval dark shape here. If you change the glossiness value of the ground material, that shape changes as well.

I am not sure if this bug is related to the dimensions of the objects which are quite big, but imagine an exterior scene where the background plane is a background image applied on a tube or a plane....

Looking forward for your news...

Dionysios -

[Dionysios.TS]

If you miss some maps from the .max file I sent no worries, I forgot to turn off the Env. Overrides slots. In any case even with them off the problem is always produced here.

Thanks,

Dionysios -

[TomG]

Looks like a couple of factors come into play here - e.g. if the plane material has no Diffuse, then the effect goes away. The dark area appears related to the area where the Sun is reflected on the plane.

The only way I could see to get around this was to use a CoronaLight material for the Tube object, which had to have Emit Light enabled, and Occlude Other Lights unchecked. (EDIT - which let me have Diffuse from the Sun, and Reflection from the Sun, and Reflection from the Tube, without the artifact appearing)

[maru]

This is a known problem with light transport when using fakes - https://coronarenderer.freshdesk.com/support/solutions/articles/5000516180-known-bugs-and-limitations
We would love to fix this, and we understand how important it is, but unfortunately it's a very hard thing to do.

[Dionysios.TS]

This is a known problem with light transport when using fakes - https://coronarenderer.freshdesk.com/support/solutions/articles/5000516180-known-bugs-and-limitations
We would love to fix this, and we understand how important it is, but unfortunately it's a very hard thing to do.

Thanks for getting back. No problem, if it's a known limitation we can live with this. Is important not to be a bug. :)

Dionysios -