This post will show how to apply a graphic to a 3D object, regardless of the presence of a UV map or not. Applying a graphic to the model will use a technique called ‘Projection’. Projection will take the contents of a layer (above the model) and push the pixles to the surface of the model and place it into the texture layers.
This toy plane will be used in this demo, and will place graphics on the top of the wings.
These two graphics are transferred to the Library panel in the desktop apps via the Creative Cloud Sync (part of the Creative Cloud Desktop application that you probably have on your computer).
For the projection method of transferring the graphics onto the texture to work, the cameras of the 3D viewport will need to see the target area. Also, projection will only place the graphics on the parts that the camera can see.
Re-orientating the plane can be done with the 3D secondary view (or by manually moving it with the 3D move tools). This panel will normally be shown when the 3D layer as well as the move tool are selected. But if it’s not shown, then it can be selected from the toolbar menu option View/ Show / 3D Secondary view.
The following panel should appear in the view port (top left)
This secondary view is showing the plane in orthographic mode, more like a 2D view, rather than a perspective (3D) view. This view can be changed by clicking on the camera (marked in red), and selecting the view (i’ll select Top view), as that is where the graphics will be placed.
The library graphic can be added to the comp, by dragging it and into the canvas. A new layer to contain this object will be created for you. The star was originally on a white background, but with a simple selection, a mask has been created to hide it.
Once the graphic is sitting on a layer above the plane, it can be pushed down using CMD+E (Mac) or CTRL+E on a PC. This will operate a merge downward action and push the graphic onto the plane and into the texture layer. Merging down will sometimes cause graphics to dissapear, if this happens see section ‘ What can go wrong when merging down?’ below.
Once merged, the graphic should be displayed but will take on the characteristics on the light and materials of the 3D scene.
If the texture is opened at this point, the graphic will be displayed blended into the texture layer. The black wiry element is the UV map and I think you might agree that it’s a bit messy, that’s because it’s not a very well created UV map. Also, you will see 3 stars below and not one, and this is because of the overlapping UV’s in the map. If the UV map gets in the way, it can be turned off by un-checking the UV check box marked in red.
N.B. When painting and texturing a 3D object it is important to have well laid out UV maps.
Without UVw’s turned on
How does the merge down work. When the merge down is actioned, Photoshop will look for a layer to place the textures on, this should be an empty/simple layer. The layer is very useful as it helps to isolate different merge downs (if there are many), as they can be placed on individual layers within the texture map. By operating Photoshop in this way will allow the textures to be kept as non-destructuve layers, for re-editing at a later point in time (you don’t need to rasterise texture layers in Photoshop CC).
I.e. A new layer is placed in the texture, this is done by clicking the new layer button (marked in red)
One the other side of the wing, you can see a colour graphic, which has been placed into a new layer above the 3D object, a mask created to cut the background out, then converted to a Smart Object.
After the merge down (CMD+E (Mac) or CTRL+E (Pc)) has been performed, the graphic is moved to the empty layer in the texture.
Some times the dialog box similar to the one below may appear. This means that there is no empty layer at the top of the layer stack to place the graphic, in this case the texture contains a Smart Object at the top most layer and Photoshop is not able place the graphic. The way around this is to make a new empty layer in the texture, then retry the operation (selecting ‘Change Texture Target’ will open the texture for you.
To get to the texture layers, click on the 3D panel and choose the material layer, in this case called ‘Material1’ under it’s 3D object. Notice that there are other materials called the same name, this is because the UVw map that contains the texture is shared across the other 3D objects in the scene (it doesn’t matter which material is selected in this case). Once the material is selected, the Materials properties will be shown (in the properties panel). To open the texture, click the ‘Diffuse’ icon marked in red below.
Graphic goes missing on the merge down?
Some times the merge down graphic goes missing, if this happens, place the merge down graphic in a Smart Object and re-try.
To see what’s possible with this technique, the Jeri model (shown below), that was created by James Stewart for the Adobe gallery at the 3D Print Show in New York was painted in exactly this way.
James Stewart’s Video about Jeri and 3D painting in Photoshop CC