Need help labeling this glass: label not showing transparency


(Splitting_Atoms) #1

So im getting further into my project… Which is a glass of beer with a label on it…
I have the label in illustrator file, SVG and transparent PNG. It has some transparent area’s on it…Which are causing me headaches

I need to now the best way of applying this label to the glass… Shrinkwrap it? Or UV unwrap it?
I tried the latter…but its not showing me the transparent areas of the label…

So im doing something wrong…problaby with the shaders?

Any help or insight is appreciated…!

here are the files


label: https://www.dropbox.com/s/8mzup2ne5lyhql6/Untitled-2.png?dl=0
label: https://www.dropbox.com/s/joimfiz9o1ff73q/Bruxelles_Blond.svg?dl=0


(JA12) #2

Cycles can’t mix materials, you have to mix it with shaders



(Splitting_Atoms) #3

Thank you so much for your quick reply…

Ive set up the nodes like you (already set it on ‘clip’ after i posted this pic)…but im not getting same result…

SO the entire glass has just one material right? And then you just unwrap the part that you want the label on? Do I need to assisgn anything?

here’s what i am getting…(i changed the background from the file i send earlier)



(JA12) #4

Move the rest of the UV’s out of the UV area. Only the faces where the texture is have UV’s on the UV area, the rest are excluded because the image is set to clip instead of repeat.


(CarlG) #5

If you want the label appear different from the backside, say i.e. diffuse or dark translucent (making it lit up slightly on the backside, as typical paper) using a dark multiplier on the texture and the geometry/backfacing node, you should apply the solidify and move the inside version of the label UV is located outside. So basically, only the ouside of the glass wall should have a label.

For the foot, you may want to use a mirror Z modifier for a “free” reflection, and remove the actual floor.
Crank up the transparent, glossy and transmission bounces to really high.
If you need shadows, you can turn off reflective caustics and manipulate shading using transparent shader and isshadowray.
The foam absolutely required refractive caustics, at least I don’t know a way of faking that.
For product shots, consider a longer lens.
If you need other textures applied (such as stains, fog, fingerprints etc), simply unwrap to a new channel that won’t interfere with the “put outside UV range” technique JA12 describes above.

I’m assuming you already know the IOR setups and proper interfaces are wrong. I didn’t tweak those, as I always end up in serious trouble trying - this looks far better than I could ever achieve :slight_smile:

Here is my node setup:



And here is the result (tweaked the scene some):


As you can see, the translucent part is a bit strong. At least compared to my own cola bottle when looking at the label from the back into the light. And I’m not too happy with the lighting, with that front/back strip being required to shed light on the label (I’m using dark strips to control glass thickness). Not sure where it came from but I ended up with a yellow tint, but rebalanced in post using a divide color node.

I really like the look of the beer and foam.


(Splitting_Atoms) #6

Hi guys, thank you for your replies… I managed to get the label transparent so im happy with that.
Im not sure if i did this the right way though…this is what I did:

  • selected the part of the glas that I knew that needed to be transparent > applied normal glass material
  • selected the part of the glas that would contain the label > applied the label material (node setup as suggested by JA12) > UV unwrapped it and scaled it so surroundings where transparent…

This gave me the result i needed…although im not sure if its the same way as JA12 suggested… cause In his screenshot i diddnt see 2 materials used… and I did use 2 materials… So what did I do different from him?

As follow up to your elaborate answer… I have a few questions that i have posted after your comments:

If you want the label appear different from the backside, say i.e. diffuse or dark translucent (making it lit up slightly on the backside, as typical paper) using a dark multiplier on the texture and the geometry/backfacing node, you should apply the solidify and move the inside version of the label UV is located outside. So basically, only the ouside of the glass wall should have a label. - I wont be needed to show the backside of the label…but its good to know for future projects… Altough… your nodesetup will also allow me to manipulate the way the label looks from the front, right?
For the foot, you may want to use a mirror Z modifier for a “free” reflection, and remove the actual floor.
Crank up the transparent, glossy and transmission bounces to really high. - Im not sure how to do this… Do I select the bottom foot of the glass (which is its onw object.) and then applie the ‘mirror’ modifier and set the axis to Z? cause nothing happens when I do that…
And so for lighting and ‘background’…you just used the front and back emmission plates that I made?

If you need shadows, you can turn off reflective caustics and manipulate shading using transparent shader and isshadowray.
The foam absolutely required refractive caustics, at least I don’t know a way of faking that. - ok so ill leave that on for the foam

For product shots, consider a longer lens. - I was afraid this would be the case… a 35mm might have to much distortion… What would you recommend… 100mm?

If you need other textures applied (such as stains, fog, fingerprints etc), simply unwrap to a new channel that won’t interfere with the “put outside UV range” technique JA12 describes above. - I want to add some condensation and drops… so i will try this method

I’m assuming you already know the IOR setups and proper interfaces are wrong. I didn’t tweak those, as I always end up in serious trouble trying - this looks far better than I could ever achieve :slight_smile: - the IOR of the glass itself is 1.415 right? I know that the beer might not be 1.000 (as it is now…)…but If I change that up… the liquid starts become transparent on the sides of the glass…which make the walls of the glass look really thick… and I didnt want that… its the lighting strips that cause that effect… so maybe if I change that lighting i can set the beer IOR to a normal setting. And im not sure what you mean with ‘proper interfaces’

thank again so much…im learing a lot from you guys


(CarlG) #7

The backfacing property splits it out, you can control however you want using this. But, on a solid walled object like this the main object need to be made from something transparent to see that backface. On a thin walled object (without a solidify), you’ll see the backface simply by watching from the other side even if main object is not glass.

I wouldn’t bother with it either if I had to to do it in a rush. But if you want it later as a general purpose asset, might just as well :slight_smile:

Lens; above 80mm should be fine. I don’t know anything about “product shots” but that’s what I found on youtube for photographing glasses. It’s also a common/good starting point focal length for portraits.

IOR, we typically use 1.45 for everything dielectric, and since glass is more reflective it should have a higher IOR. I tend to use 1.65 for anything architectural, but mostly for separating the specular property more from the surroundings. Anything between 1.45-2.00 would be “legal”, but if you want accurate you should look it up. Adding metallic oxides to the glass will alter the optical properties, such as increasing IOR.

As for lighting, I changed it into what I learned from youtube tutorials photographing glasses. Thought I’d give it a go just for giggles. There is also a lot of things we can learn from film tutorials. Don’t limit yourself to thinking Blender only, even if there are things we can’t do.

As for surface interfaces, I’m leaving this one for others to answer, as I have never been able to get this right (on my very own).


(Splitting_Atoms) #8

Thank you for you reply, ill change up the IOR on the glass and change the lens length. And yeah, lighting is always tricky… there’s so many options to choose from that will totally change the scene up and make more or a lot less realistic…

Im just glad that this community is so helpfull cause Im still learning this program and its not always easy to get realistic results.

Which brings me to my final question for this thread… If I wat to add a texture (noise or something like paper) to the label… to make it less plastic looking)… how would I do that? I know I need a noise node or image texture node…but Im not sure where to place this in the node setup that you guys provided earlier…


(JA12) #9

I used one material because using two is redundant. With two, you have assigned some faces a glass material, and some faces with again a glass material and a label.

Instead, I used one material and use the image alpha as a mix factor. The label gets white (1), the rest get black (0), and the mix shader puts a corresponding shader on those areas. Enable node wrangler addon and ctrl+shift+lmb click on the node to see the socket output, preferably in rendered view.

It’s already mixed for you with the image alpha. You can change the appearance by changing the node tree branch that belongs to the label. If you want an uneven surface for it, could try a bump map. Texture -> bump node -> diffuse normal socket.

Although, coated shiny label or a matte one, the uneveness will be subtle, and depend on the light and viewing angle to even see it. Apart from the obvious reflection change of course. So instead of using bump, you might want to have a reflective component to it (glossy) and control that by changing the roughness