Strange faces on my models

Hi there !

I’m a student and for one of my 3d works, i got to modelize some potions. I decided to do it on blender since it’s the software we are learning this year. Though, when i applied a transluscent material to my meshes, well it shows some weird faces darker, and i can’t get to know why. My normals are OK, not reversed, my topology is good (i guess at least aha).

Could you help me with this ? Thanks a lot !

Smoothed shading? Higher values for light path bouncing? Do you already have an inner geometry for the potion (left bootle)? Maye scale it because of overlapping geo?

Hey !

Thank you for your answer.
I got smooth shading though with auto-shading with 30° activated. I also have an inner geometry to create the bottle effect. I’ll try what you suggest, keep you tuned !

why did you add translucent to the bottle is it to color the bottle?
if only to color the bottle you don’t need to add translucent you can open the color panel on the glass shader.

Also, if you have a separate ‘liquid’ mesh, try to remove the inner part of the bottle that would overlap.
That way it’s easier to render, and it gives you a better mix/visual result between two different IOR’s.

It’s an old trick that works for all renderers.

try doing this, just to make sure the mesh topology isn’t a problem.

press Tab on the bottle then Right click then Merge by distance.

I tried that just now, and it doesnt seems to be the problem… i’ll keep looking for a solution

can you share the blend file so I can investigate where the error is

Sure ! But since i’m a new user you got to download it from here :

I checked your attached file.
First I looked on the mesh - its clean. Than, I tried normals but they are also good, so the last thing could be in the material. And here is the thing - you are looking on backface (checked in material settings). You can change it to Hashed, but it will be noisy. Also, why are you using alpha for those potions?

From left to right:
Alpha Hashed, Alpha Blend and using SSR with a basic trasmission material (+ mesh for fluid with basic cherry material).

Also, Alpha Blend without backfacing:
The settings itself:
with Backface

without Backface

Oh thanks for that detailed answer ! I used alpha to change the opacity of the objects.
How do you use SSR like the 3rd one ? And is it possible to add it a color ? I’m following a stylized concept art so its colored and we can see the “inside” bottle (cf so i’m looking for a similar look !

using alpha blend is the best result but unfortunately it has a bug.

I would not say so. Its too late in my country, but if use transmission + glossy and enable SSR in Eevee, than play with Freestyle and some point lights (and not only light) it can be achieved. The only think to deal with is IQR, which is totally transparent if use 1, and making weird refractions on higher numbers (it just stretches inside of potion).


Freestyle Edges:
Freestyle itself:

Tried in Eevee with Screen Space Refraction, Freestyle and Bloom turned one. Thats just a thought how to replace alpha blend and I agree that some thing really need a fix, thats for sure)

Wow ! Thank you for that ! I tried to put similar values as you for the mats though i didn’t came to the same result, even in eevee. I don’t have the feeling of transparency… Did you separate the two parts (in and out) to find that effect ?

And for the freestyle i’m not using it but it’s always cool learning a new thing, so thanks !

About the transparency material, did you check refraction in material settings and SSR in render settings? Also notice, that its render, not material preview. Hope it helps. I will wait for your respond.

I did the edits you suggested me (on render settings) and it looks quite better !! The problem is still : can’t see through it like glass.

If u want to see objects through in Eevee, than I would recommend to look that video:

If u want it in Cycles (but its noisy at low samples quantity), than remove glossy and just connect material to the Output.
Give it a try)

That video is really interesting ! It helped me a lot ! Thank you for helping me during these 3 days, it means a lot.