Author Topic: Ask for help with reflection problem of glass material  (Read 2029 times)

2022-12-04, 15:46:36

15845646656@163.com

  • Active Users
  • **
  • Posts: 7
    • View Profile
I have a problem when rendering the glass material. The refraction of the glass material seems to be incorrect, and there will be some uncontrollable bending and light and shadow in the refraction. Why do you ask for help

2022-12-04, 19:16:56
Reply #1

burnin

  • Active Users
  • **
  • Posts: 1532
    • View Profile
Hello & Welcome!

Care to make it easier to help you and provide a scene with a reference image? 
Since issue can be anything from bad geo, lighting, materials...

2022-12-05, 03:11:09
Reply #2

15845646656@163.com

  • Active Users
  • **
  • Posts: 7
    • View Profile
Hello & Welcome!

Care to make it easier to help you and provide a scene with a reference image? 
Since issue can be anything from bad geo, lighting, materials...

Thanks for your help

2022-12-05, 11:35:39
Reply #3

burnin

  • Active Users
  • **
  • Posts: 1532
    • View Profile
What about your visual reference? What should it look like?

2022-12-05, 19:03:47
Reply #4

romullus

  • Global Moderator
  • Active Users
  • ****
  • Posts: 8778
  • Let's move this topic, shall we?
    • View Profile
    • My Models
Check if bottom of the glass doesn't touch ground plane. It should float slightly above the ground, otherwise there's a risk to run in z-fighting, which leads to visual artifacts similar to that in your attached picture.
I'm not Corona Team member. Everything i say, is my personal opinion only.
My Models | My Videos | My Pictures

2022-12-06, 14:36:37
Reply #5

Beanzvision

  • Corona Team
  • Active Users
  • ****
  • Posts: 3809
  • Bengamin
    • View Profile
    • Cormats
Hi, I reproduced your model on the right and can't say I see any issues here either. When you say seems to be incorrect, can you share with us how it's meant to be?

Bengamin Jerrems l chaos-corona.com
3D Support Specialist - Corona l contact us
Corona Uploader l Upload
Portfolio l Click me!

2022-12-06, 15:00:06
Reply #6

maru

  • Corona Team
  • Active Users
  • ****
  • Posts: 12708
  • Marcin
    • View Profile
Perhaps the object is just too low-poly? Maybe subdividing it more would help?
Marcin Miodek | chaos-corona.com
3D Support Team Lead - Corona | contact us

2022-12-09, 10:44:04
Reply #7

tuami

  • Active Users
  • **
  • Posts: 165
    • View Profile
I have a similar problem when bevel when using bevel deformer. Relection is distorted

2022-12-09, 10:57:00
Reply #8

15845646656@163.com

  • Active Users
  • **
  • Posts: 7
    • View Profile
What about your visual reference? What should it look like?

Something like this very nice refraction

2022-12-09, 10:58:48
Reply #9

15845646656@163.com

  • Active Users
  • **
  • Posts: 7
    • View Profile
Check if bottom of the glass doesn't touch ground plane. It should float slightly above the ground, otherwise there's a risk to run in z-fighting, which leads to visual artifacts similar to that in your attached picture.

Thanks, I'm also wondering if it's because of the environment

2022-12-09, 11:01:51
Reply #10

Nejc Kilar

  • Corona Team
  • Active Users
  • ****
  • Posts: 1245
    • View Profile
    • My personal website
I have a similar problem when bevel when using bevel deformer. Relection is distorted

Don't forget to hit that "Phong Break Rounding" button (second to last at the bottom) on your bevel deformer otherwise the flat surfaces are going to get smoothed as well and your materials / objects (refractive or not) won't look as they should. They'll look weirdly bendy.

As a tip, I set that "Phong Break Rounding" toggle to on and just save it as a default Bevel preset so I don't have to bother with it every time I create a new bevel deformer.

The "Phong Break Rounding" thing, when set to off, is great for organic surfaces but really not cool for non-organic stuff.
Nejc Kilar | chaos-corona.com
Educational Content Creator | contact us

2022-12-09, 11:07:50
Reply #11

tuami

  • Active Users
  • **
  • Posts: 165
    • View Profile
I have a similar problem when bevel when using bevel deformer. Relection is distorted

Don't forget to hit that "Phong Break Rounding" button (second to last at the bottom) on your bevel deformer otherwise the flat surfaces are going to get smoothed as well and your materials / objects (refractive or not) won't look as they should. They'll look weirdly bendy.

As a tip, I set that "Phong Break Rounding" toggle to on and just save it as a default Bevel preset so I don't have to bother with it every time I create a new bevel deformer.

The "Phong Break Rounding" thing, when set to off, is great for organic surfaces but really not cool for non-organic stuff.


Thanks that worked!

2022-12-09, 11:16:47
Reply #12

15845646656@163.com

  • Active Users
  • **
  • Posts: 7
    • View Profile
Hi, I reproduced your model on the right and can't say I see any issues here either. When you say seems to be incorrect, can you share with us how it's meant to be?



I think the refraction in places like this is a bit sharp and not smooth. I don’t know if it’s my environment or the model.

2022-12-12, 14:11:54
Reply #13

burnin

  • Active Users
  • **
  • Posts: 1532
    • View Profile
to represent image realistically, you must take into account all phenomena that occurs IRL
no glass is perfect - it's imperfections and medium/vol. properties that characterize half of it , other half being the environment (could use better one, more dynamic to get a play w/ caustics)

here's a bit leveled up to get you going further... you can also add roughness/dirt, turn on dispersion, change env...

2022-12-14, 14:53:30
Reply #14

JPeters

  • Active Users
  • **
  • Posts: 87
    • View Profile
And if all else (modifiers) fail, just poly-modelling it usually fixes all the errors, but it takes a bit more time :)