Problems rendering glass

[itsallgoode9]

So, here's an empty champagne bottle i'm working on, but the base is turning out completely black. Is there any way to alleviate this problem?

This render is Pathtrace but PMC looks exactly the same. I have spec bounces turned up all the way to 32 in render globals just to make sure it's getting enough light bounces in the base. the bottle on the left is modeled the standard way andthe bottle on the right is modeled as a crossection, which works better but still has alot of weird stuff going on. is there a render setting that needs to be adjusted or am I doing something wrong. I have this problem on pretty much every bottle I render.

[face_off]

Have you tried adjusting the ray epsilon?

[itsallgoode9]

thanks for the suggestion. I just tried messing with that but nothing changed for the better

[linvanchene]

thanks for the suggestion. I just tried messing with that but nothing changed for the better

All I can offer is only a suggestion based on past experimentation and speculation:

Did you try to add one or two more subdivision levels?

When rendering glass in the past I sometimes got the impression that light rays passing trough volumes yields higher quality caustic effects with higher polygon count models.

When I experimented with this I added the subdivision levels in the host application of the plugin.
I did not try this yet with OctaneRender native subdivisions.

[prodviz]

Test cranking to 1024 spec depth too, just to rule this out.

[itsallgoode9]

just tried both of those suggestions but neither changed anything. I'm trying to export my scene so I can upload it here but when I export out of maya as an orbx file it is like 200mb for some weird reason.

[prodviz]

I'm running maya, so could have a look for you, if you strip all bar the glass out.

[whersmy]

itsallgoode, is the ground tangent with no offset to the glas bottom? are there tangent surfaces in the model? this can cause artifacts like that

is the liquid inside the bottle tangent to the bottle itself?

[itsallgoode9]

That would be awesome, thanks prodviz, here it is.


Hey whersmy, i'm not sure I understand your usage of the word "tangent" in this case. for your last quesiton, the bottle is modeled as an empty glass bottle, no liquid

[whersmy]

okay, can you move the bottle a bit up in the scene so it does not touch the ground?
and then see if the spot goes away

if theres not liquid then that`s not a problem

also, what is your scene scale?