2
$\begingroup$

i have created a very simple glass of orange juice and placed it on a wooden table. when i look in viewport render it looks like this -- viewport render

but when i render it changes to this-- final render

in both times I have used 64 samples. I thought it is the reflection of the table and tried to render it without table. The result was same. can anyone enlighten me how can I achieve the render result like viewport result?? thanks in advance.

here is my blend file :

$\endgroup$
3
$\begingroup$

Short answer at the end, longer but more detailed way, keep reading..

Checked the file as well, had to tinker a bit as the textures were not there (used a different HDRI to lighten the scene). When i rendered and adjusted the glass/juice sizes to slightly overlap (yes, please bear with me) the picture still did not come out right, the juice was looking weird. After some tweaks on the material i could not get it better and checked the face orientation(normals) ... red normals are pointing inside Always a good idea to check normals (Face Orientation). display normals/face orientation

Option to display at the bottom of the picture(above).

As i mentioned above, i use to overlap the liquids in glasses to make it look more realistic (in regards of reflection and refraction), believe i am not the only one, but that aside, pictures are better then words. glass and juice overlap or not Left side with the juice geometry slightly inside the glass walls, while on the right the juice geometry is smaller and thus not intersecting with the glass. The refraction and calculation of liquids in glass always was and most likely will be an issue in regards of realism. But with the intersection on the left the reflections/refractions are only calculated for glass then juice and not for glass then air then juice, which leads to those floating liquid in a glass effects.

Not the main issue, but i would like to also point out that the material on your table, in the "Image Texture" nodes the roughness and normal textures should be set to "Color Space":"Non-Color". Rather then me trying to explain, others did already, here a link that should clear some things up as well Understanding sRGB, gamma, color values..

Now the main issue with your juice, sorry for the long post.

It was essentially the normals(Face Orientation) of the juice-mesh that were wrong.

|improve this answer|||||
$\endgroup$
  • $\begingroup$ Thanks to both of you. My problem was solved. $\endgroup$ – Biswarup Hajra Nov 20 '19 at 4:19
  • $\begingroup$ This is a brilliant answer. Learned a lot of stuff here and also reduced my prejudice about overlapping faces. (I also want to slap myself for not checking the normals :)) $\endgroup$ – Jachym Michal Nov 20 '19 at 10:51
1
$\begingroup$

I downloaded your file and was able to replicate the issue.

The issue:
The juice object and the glass object have overlayed faces.
This causes distortion, because Cycles cannot tell which ones to render.

The solution:
You need to scale down your juice object just a bit, so it doesn't touch the glass.

Original mesh with distorted materials
enter image description here

Result with the juice object scaled down.
enter image description here

Note:
The reason it looked okay in viewport is probably that viewport rendering is ignoring some more complicated physics.

|improve this answer|||||
$\endgroup$
  • $\begingroup$ Thank you sir. Your help solved my problem. $\endgroup$ – Biswarup Hajra Nov 20 '19 at 5:47

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.