How to properly UV Unwrap a whisky or wine etc bottle?


#1

I am always running into problems when texturing glass bottles, for example using selection sets and displacement for embossed areas, getting nice scratches and bumps using texture maps with different projections etc. I’m forever getting artefacts where displaced and non displaced areas meet etc etc.

I tend to create low poly models using the cylinder primitive and extruding edges and creating cuts etc for the bottles that I then put in an SDS to get a smoothed result.

I have become convinced I could make life easier if I had a proper UV map of the bottle, with maps for the inner surface and the outer.

What’s the best way of unwrapping a bottle properly so I end up with decent UV maps, and does anyone have an example of what they are supposed to look like?

Also when I unwrap, should I be unwrapping the low poly model, or making the SDS editable and unwrapping that?

(Secretly hoping Noseman might show me the ultimate way!)


#2

Realised I already asked this a while back:

still don’t really understand the best way to do it though!


#3

So had a go with the UV peeler and created islands for the outside and inside of the bottle, and the outside base and inner base, and the top of the neck.

Would this be considered a good UV Map?


#4

Sometimes the UV’s are fine but they aren’t applied correctly with teh SDS object in play. I’m wondering if this is where you are getting distortion. You may want boundary or edge options on your SDS…instead of the default “Standard”


#5

The distortions and artefacts I get are caused by stacking glass materials, some with displacement maps some without, and using poly selection sets. I’m keen to start using a workflow where I can have one UV map for my bottle and then create maps for displacement, bump etc that apply to the whole surface.

The result from the UV map I created looks ok-ish from one side of the bottle, but distorted from the other. Is there a way to unwrap it without this distortion?

I’ve read about ‘pelt mapping’ in 3ds Max - thought that might work. What’s the equivalent in c4d?


#6

Select the points on the edges of the main body of the bottles UVs and straighten them out.

Maybe something like this? You may need to scale the neck a bit to get a better ratio, but this was just a 2 minute example :slight_smile:


#7

The unwrapping is not so difficult as demonstrated.
I would focus on the Displacements and you should make sure when using the default “Intensity Centered” that your level is 50% grey
Better still, to use just “Intensity” so that Black is level and White is full displacement.

Another thing relating to bottles is that you don’t ned to have the whole thing as 1 object, or 1 continuous geometry.
Both glass and interaction between glass and liquid are handled with slight overlaps.
If somebody wants to provide a model, I can unwrap it and report back with best practices.


#8

Would this be considered a good UV Map?

care to share the model?


#9

For sure Nose, can share later, got to take mother for heart scan this morning!


#10

Here you go Nose

BottleNose.c4d (177.9 KB)


#11

So, your attempt to conserve the polygon size ratio along the bottom (thick) and neck (thin), is the reason you get the distortion on the back.
Just like in real life, if you where to apply a continuous label to the bottle, it would have to be shrink wrapped, causing it to distort where it shrinks.
Depending on exactly what you want to place on the bottle (for example a small label at the top and a big one at the bottom, or just a single label e.t.c.), you should chose the unwrapping method.
For stuff you intend to add that wrap around the bottle, like scratches, drops e.t.c., you can either use Bodypaint, that will do the wraparounds for you, or you should add more than 1 materials wrapping in different directions. That way you won’t have a visible seam, but it’s more work.

Pelt mapping seems to be a relaxation algorithm, but it doesn’t cater to “structured” objects, as it introduces distortion.

Here’s a scene with the bottle Broken into:

  1. Outside
  2. inside
  3. UVs are made using the Peeler and the polygon size is respected, so it’ up to you to deal with the wrapping around the back
    (HDR from the Content Browser)
    https://www.dropbox.com/s/u6o5vdiq39hnxcc/bottle%20Nose%2001A.c4d?dl=0

I have added Displacement maps where the “water level” is 50% grey.
Also, the wine is slightly offset so that the “nested dielectrics” work and the glass - wine interaction is correct


#12

Thanks Nose lots to digest!

Questions:

  1. When you say use Bodypaint for scratches, would I do that by using the paint wizard first? I’d like to take the work into photoshop if possible - can you elaborate?

  2. Using 2 materials wrapping in different directions - can you explain this a bit more?

The plain effector is a neat trick for scaling the liquid btw!


#13

the problem working in a 2D painting software, is that you need to take care of UV island continuity when painting, whereas 3d painting software like body paint, allow you to paint on the model, and the software takes care of that. Essentially, that’s the only point for any 3D painting SW.
You don’t have to use the wizard, but if you do, make sure to deactivate “Recalculate UV” in STEP 2.
You can even work in both PS and BP, as we can load and save Layered PS files in BP natively.
Have you done any BP 3D painting in the past?

“2 materials in different directions”, I didn’t phrase that properly.
What I mean, is use many small patches of materials (decals) instead of one that occupies all the bottle.
You can make a few different patches of scratch materials, and randomly distribute them over your bottle using flat or cylindrical projections.