Corona Refract strange behavior

[fobus]

I found a strange behavior of refraction in simple scene that I can't understand. Just a simple cylinder and plane with simple materials, but some refraction error ins presented. Dark line contour around cylinder. Can anyone resolve it?

Picture:


Corona v7.2
Scene in attachment.

[maru]

You forgot to mention that the cylinder has absorption. :)
After removing absorption, there is still a bright outline but I'm not sure if this is a bug.

Any chance this scene is extremely small? This effect disappears if you scale the objects up.

[fobus]

Thanks for testing it, Maru. I have huge scene (350 Km of seashore) so I can't scale it up. And absorbtion of course is needed for sea water. At my sight in is not right to see this "feature" with absorbtion. I see it as a bug...

[maru]

(350 Km of seashore)

This might be another cause.

Let's wait for Keymaster's opinion.

[Ondra]

how big is the object and how far away from origin it is?

[fobus]

The main object is huge. Huge enought to fill max zoom in 3ds max. It is mountains with sea shore and hotel at this shore. My water object generates this bug when it intersects with sand at beach.
Scene in first post not so big, but this behavior is present to show it.

[fobus]

I moved test cylinder in origin and this effect still there. Is smth wrong with me or may it be a bug?
Scene attached.

[fobus]

I've tried to avoid it by attacching seabed to simple plane (in test scene this helped) but in general scene it has no effect. At intersection with plane there are no line visible. But line at intersection with seabed remained. Plane was 2996008.0 cm * 3794411.0 cm. So It scale had no effect to this behavior I think.

Illustration:

[borisquezadaa]

Maybe thats a work for "BSDf Only" Sample mode under lights "Development/experimental stuff".

[fobus]

I think not. Have tried all 3 modes of this sampling methods.

Here is the main scene fragment with this effect (attachment):

[borisquezadaa]

Maybe a material related issue?. Is like the geometry itself is creating some shadow. I found now that if you activate caustics(slow) under water material the black lines goes away.

[fobus]

No. You can create all new mat for water with just white refraction and some absorbtion (with no caustics) and get the same black line...