Difficulty with Semi-Transparent Plastic Material

Hello, I am very new to blender so sorry in advance for any obvious things I may have missed. I am trying to replicate a pharmaceutical infusion bottle like this:


I have applied a solidify modifier to the main part of the bottle (the loop on top is a separate object), and tried countless different node setups to replicate the transparent plastic material but no matter what I use it ends up looking gray or silvery. Or if I use a glass shader it obviously looks like glass and not plastic. Mostly I just copied node setups from other blends I found on this forum. I am out of ideas and would appreciate any help getting this plastic material look right!
Here is my current render and node setup. The glass absorption is the plastic material, and the rest is for the sticker label. I haven’t put the liquid inside because I wanted to get the plastic right first.
I would put a picture of my current node setup and render but as I am a new user I can only upload one picture.
Blend file:
https://ufile.io/votwc
Thanks!

Reflective / Refractive materials need something they can reflect. If this is just the default grey Blender Environment, it will look dull.
Have you tried using an Environment Map? On https://hdrihaven.com/ you can find many free 360° Maps. Just get one and in Blender apply it like this:
2018-07-20%2021_52_32-
As Color use Environment Texture and load your exr / hdr file.

Other than that, maybe try adding some transluent shader to your Diffuse:


not physically accurate, but it might work here.

(Also your File isn’t working because you didnt pack the texture. use File -> External Data -> pack all into .blend if you want to save the textures in the Blendfile).

I made a couple of different setups for this. Please pack your textures into the blendfile next time. I had to make a placeholder image. Here is the blend: paracetamol-infusion-bottle8-NEW-MATS.blend (1.2 MB)

The first setup adds refraction to translucency (inspired by stuntkoala’s suggestion):

I tried to be more physcially correct with the second one. The material ended up being a lot darker than the first. I also couldn’t get the label to display for some reason. Maybe it’s a glitch with using two material output nodes or something (its the first time I’ve used two outputs in one material):

This is what I came up with.

This is the node set up.

Make sure your bottle has thickness or this does not work.

The problem is you need the backside faces to act like they are front facing. This set up will fix that. This will give you more of a plastic look instead of a glass look.

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Could also check stuff @

possible suggestion here:

Materials is based on two principal events - rays that bounce off specularly and rays that enter the material, controlled with a frensel node. Glass is simply fresnel, refraction, and glossy. Plastic is very similar to glass, but setting it up manually allows separate controls over refraction and glossy roughness; evidently the glossy roughness is quite rough in the OP’s image.

The refraction can further be split into happenings, such as mixing with transparency, translucency, diffuse, all those other shaders (could be mixed with pure mixing or layer weight/facing, but generally fresnel would not apply). Currently on vacation so not able to play with file on this crappy laptop.

here my try.with the value on the left ,you can control the opacity.i added a solidify to the mesh,as real objects have some thickness.the rgb curves are better for this material.i increased the transparent samples to 12,to eliminate black spots from overlapping mesh in the view.

2 Likes

Wow, thank you everyone for all of your advice! I am going to go over everyone’s recommendations and try for the best results. I will remember to pack my textures this time. Will post results soon.

Ok, sorry for the delay but here is my attempt using icyou520’s node setup.

Looking better but if anyone has any suggestions or wants to tweak it feel free.

Blend file (packed this time)
Paracetamol infusion bottle icyou520 blend.1.blend (1.3 MB)

Thanks!

Forgot to put the node setup. The highlighted nodes are the actual bottle material, everything else is the sticker label.

Here is a link to a thread with a similar topic:

Plastic of this kind is quite rough compared to glass which is smooth, so add some roughness to the glass shader.
But best thing here I suspect would be to make a custom glass shader from the start:
Fresnel to mix refraction and glossy as a standard glass.
However, the refraction part should be mixed with another mix of diffuse and translucency to fake some scattering effect. You could also try some volume scatter, but I find it very costly.

When I append your bottle object, geometry seems far too big and appears very messy.

Hi CarlG, thanks for the advice. Sorry if this is a silly question but when you say “geometry”, does that mean the # of vertices used? Would that be improved by choosing the appropriate # of vertices from the initial mesh (in my case cylinder)? If so, how do you choose the correct number when you create the mesh?

Thanks

Big as in physical size, like several meters tall. Lighting will be affected.
Messy as in lots of loose geometry, unconnected faces and so on.

can you please share the blend file? im trying to copy your node but it doesnt work

Are you doing that in eevee or cycles? This is a really old post made from before eevee was added to blender. I dont have his original file, but I put together one based on what was in his screenshot:
plastic.blend (1.1 MB)

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im doing in cycles… thanks for the help now I will try to apply it in my project. thanks once again

There is nothing special,IIRC it has one HDRI for lighting,and the material as posted.