Glass + displacement giving me strange distortions

[Chrmez]

Hi,

I've modelled a bottle that I want to have a displacement map on. I've tried bump maps but it didn't turn out the way
I wanted + I got a ton of fireflies with it. Displacement map looks way better.

But as soon as I put a displacement map on my glass, I get really weird distortions, it looks like the glass is super thick instead of the thin
look that I'm after. The displacement is really subtle and not thick at all so that isn't what is happening.

Is there anyone who can help me out ASAP to solve this weird issue?

Example:

https://www.dropbox.com/s/f7e0x8j9l179w ... s.jpg?dl=0

(I turned off all the lighting so nothing is reflected to make it easier to pinpoint the problem)

[Chrmez]

Ah yeah, before anybody asks. The displacement map is not negative. Background is black and the pattern is a very subtle gray, and then just 0.1cm height.

[Chrmez]

Hey guys, sorry to have to bump this thread. Have a deadline coming up and I still haven't been able to solve it.

I've uploaded the scene file for you to take a look at. You can clearly see how weird the liquid looks in the displacement mapped bottle to left.

Any help would be massively appreciated!

https://www.dropbox.com/s/4w5bxb4mq1qn2 ... n.zip?dl=0


Cheers!

[bartolos]

Hi,
I had the exact same problem but with regard to the surface of the swimming pool...
viewtopic.php?f=30&t=56738

The problem disappeared when I replaced the geo of the water surface (which was basically a flat circular plane) with a basic Plane (square shape).

I have no idea what's the cause of such behaviour. Looks like a wrong shading normal or dot-product calculation in the octane specular material for some specific geometry but only with displacement enabled.

I hope somebody finds out what's up. I wish u luck with your deadline.
Cheers,
B

[Chrmez]

Hi,

I've modelled a bottle that I want to have a displacement map on. I've tried bump maps but it didn't turn out the way
I wanted + I got a ton of fireflies with it. Displacement map looks way better.

But as soon as I put a displacement map on my glass, I get really weird distortions, it looks like the glass is super thick instead of the thin
look that I'm after. The displacement is really subtle and not thick at all so that isn't what is happening.

Is there anyone who can help me out ASAP to solve this weird issue?

Example:

https://www.dropbox.com/s/f7e0x8j9l179w ... s.jpg?dl=0

(I turned off all the lighting so nothing is reflected to make it easier to pinpoint the problem)

That does indeed look like the same problem. I already tried switching the liquid out but it didn't do much for me. Distortion also looks like it's worse
towards the bottom in my case. Not sure if it's a UV-problem of the bottle.

[bepeg4d]

Hi Chrmez,
yes correct, the issue was the flipped UVs. Here is your file in Shading normal mode:

and here is the result by flipping horizontally and vertically the bottle uv and the texture:

GlassdistortionB.zip

(4.82 MiB) Downloaded 180 times

ciao beppe

[Chrmez]

Hi Chrmez,
yes correct, the issue was the flipped UVs. Here is your file in Shading normal mode:

Screen Shot 2016-11-02 at 15.20.02.jpg

and here is the result by flipping horizontally and vertically the bottle uv and the texture:

Screen Shot 2016-11-02 at 15.15.25.jpg

GlassdistortionB.zip

ciao beppe

Oh wow, thank you so much! Good bye bump map fireflies!

Cheers man, I owe you something. Let me know if you ever need inverted UV's

[bepeg4d]

happy rendering
ciao beppe

[bartolos]

Thanks that explains everything. Double checking UVs for the win!

But anyway ... that might be a problem with implicit objects (like in my case) where u cannot simply flip UVs. You would need to convert it to editable mesh and lose the construction history capabilities...

Thanks anyway.
Cheers

[bepeg4d]

Maybe you can check the orientation and order of the splines and vertices to correct the original parametric mesh
ciao beppe