Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] Bug Reporting => Topic started by: makco on 2018-08-10, 18:19:09

Title: Strange behavior with map on Fresnel IOR
Post by: makco on 2018-08-10, 18:19:09

Dear Corona Team,

I think i found a bug on the behavior of the Fresnel IOR of the corona material when using a texture.
This very unpredictable behavior happens where the texture used almost fades when the camera is further or less zoomed in to the object, and the material is represented like a completely different material. Please look at the image attached that explains the issue.

I was just wondering if this is something you guys are aware off... it becomes a big problem when using corona with packages like substance, or 3D Coat, where the metalness controlled by this parameter is commonly used.

For the time being, will use a layer material but was hoping this could be looked into.

Thanks,

Martin.
(http://www.moso-studio.com/Test_moso2/wp-content/uploads/2018/08/Fresnel-IOR-bug-corona.jpg)

Title: Re: Strange behavior with map on Fresnel IOR
Post by: makco on 2018-08-10, 18:54:36

As an update, this happens as well when doing the same setup using CoronaLayer Mtl.
Vray seems to do the same... however it handles it better as one needs to zoom in extremely close for the shading to change.

Title: Re: Strange behavior with map on Fresnel IOR
Post by: pokoy on 2018-08-10, 19:27:41

Are you moving the camera? What happens if you use the zoom factor instead of moving it?
The difference is puzzling...

Title: Re: Strange behavior with map on Fresnel IOR
Post by: makco on 2018-08-10, 20:24:02

No, that's what I thought.. camera isn't moving... I'm just zooming in... that's what makes it very strange.