Last week we covered how to add a label onto a bottle using the Projection/merge down method in Photoshop CC 3D. As mentioned, this is beneficial when the label is the same size or smaller than the part of the object that is facing the camera. But what if the label is larger than the object face?
For example, this label, unless is reduced in size will likely need to be wrapped around the hidden areas of the bottle face.
The other issue is that the milk bottle is only a single shell, therefore adding just a texture to it will cover the whole bottle (as shown below).
hmm, not really what we would like to see.
So what happened, and why does it look like this.
Because the bottle is a single shell, the textures will be added to the whole shell, but using the UV(w) maps to associate the texture to the polygons of the model. Opening the texure map will show what is going on with this texture and 3D model.
When the UV map was created, it was created in a way that split the maps into many islands, also the maps are not really unwraping the object in the most efficient way. To get around this, you could project the parts of the image on the model (as in last weeks post). Also, the image can be mapped to the UV(w) maps using Photoshop’s 2D tools like warp etc. A better way (in my opinion), is to properly re-create the UV(w) maps for the intended use and describe where the unwrap starts and finishes. To do this we will need to use a 3D software package that is able to edit the UV maps. For this (as in previous posts, we will use Cinema 4D).
3D Objects can be exported direct from Photoshop (this is handy if they are inside a PSD or a 3D PDF). To export an object from Photoshop, rightclick on the 3D object in the 3D panel or from the 3D layer choose Export 3D object/mesh.
Inside Cinema, you can see the UV, as we saw in Photoshop CC (without the texture). Note Cinema is in BP UV Edit mode, this allows you to see the UV and edit it (if/when required).
The old UV(w) map can be removed if required, by deleting the checkerboard icon on the object definition. However, for speed, we can just isolate the part that we need and work this way. This will be up to you, but either way is perfectly fine. For this exercise, i’ll keep the original UV and work with the areas that are requried for the label.
Move Cinema 4D into Edge mode (marked in Pink below) (the Standard interface is shown below (marked in yellow), this makes it easier to access the tools required for the next steps (your environment might be different to this)). You can clearly see the Polygons and edges and from this, you will be able to work out how the model should be cut for placement of the label.
To make the cuts, we use various selection methods to tell Cinema where to cut the object. A combination of ‘loop Select’, ‘Live Select’ (plus other selection tools, as and where required) and holding the SHIFT key down to add multiple edges to the selection. Then the active selection is saved by selecting from the menu bar Select \ Set Selection (and a meaningful name is given (marked in green above)).
As the UV(w) has already been created, i’m going to use this as a base, and just re-organise the selected section of the model. I’ve moved Cinema into BP UV Edit mode (marked in red), then selected ‘Relax UV’s’ (marked in green, we don’t want to re-created the UV(w), so projection has not been selected on this occasion). Before ‘Apply’ relax UV is pressed, Cinema needs to understand where the edges are, the small trangle (marked in pink (left)), holds the selection that will be used (right). This triangle needs to be dragged to the ‘Cut Selected Edges’ text box and both ‘Cut Selected Edges’ and ‘Use Tag’ need to be turned on. Then ‘Apply’ (keep LSCM selected) can be pressed.
In this case, the UV’s that will be used for the base will be re-created (splitting off any Polygons that are no longer included in this UV(w).
Below shows what happend as part of this action. The polygons for the base of the object which were attached to the original UV before the relax operation have been re-allocated, and are seperated as part of the UV map (these poygons are represented by the arc underneath the polygons that were cut within area marked in purple below). However, this part of the UV can now cause a problem. If the object was painted/textured on at this point. The polygons that are crossing other polygons, would also take any paint/texture at the same time. This can actually be usefull for getting consistency of small parts, but in this case it’s not to helpful. The polygons need to be seperated and the UV(w) cleaned up some more.
To clean up the UV(w), Cinema can be moved into Polygon UV mode (marked in green below) and the UV’s can be selected (marked yellow) in-line,direct on the UV (marked in pink on either side of the screen). To select the polygons, once the tools have been selected, just select them on the right hand (UV panel), when selected they will turn orange. It’s clear that the UV that will contain the label is only selected and the re-formed polygons have not been selected, as they are still black (on both representations).
Using the rotate, scale and move tools, these UV’s can be moved and re-positioned out of way, allowing clean up the UV map. Selection of the UV polygons direct on the 3D object can also be done using these tools. N.B. If you do have UV’s overlapping it can take a little while to seperate them, but a clean UV(w) will pay off in the long run.
After a little time, the UV(w) looks like the following. (In another post we will look at positioning the UV(w)’s in the correct direction, based on textures that will be applied later).
Now the UV(w) has been cleaned and moved around to create a good size for positioning the texture on in Photoshop, the next step is to save it out of Cinema and back to Photoshop. For this, i’ll use either the DAE (collada v1.4) format or the OBJ format, these can be found on the file export menu.
Bringing back into Photoshop and opening the textures once again, will hopefully show the new UV’s.
This will now make it much easier to add the label. Adding the label can be done in mulitple ways, either direct on to the UV using a standard layer, or added as a texture, then moved into the desired position using the layer and Photoshop’s transform tools.
The result can be seen on the 3D model, as soon as the changes to the texture have been saved. In this case the label is inverted, so the transform tools can be used to flip it around.
If you notice on the image above, there is are two tabs on the label that are rising above the label, this is due to missaligned UV’s on the UV(w). We can fix this, by heading back into the Cinema. By using the Selection tools (magenta) and the Magnet tool (blue), the rougue polygon(s) can be manually moved into it’s correct position (yellow) and snapped (green) into pace.
When re-exported back into Photoshop, the image is represented much better (more time and patience will give much better results).
Hopefully you can now easily place a label on any object, bottle or not !
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