Painting on 3D models in Photoshop CC was significantly improved in 2013 by moving 3D painting to the Mercury Graphics Engine. This improvement has significantly increased accuracy and time when texture painting in 3D. So, how does it work?
To demonstrate, let us take this model (shown below) and paint it with the GPU accelerated texture painting ability. You can see below I have loaded a simple .STL 3D printable object into Photoshop (Photoshop CC supports .STL files, as well as the usual Wavefront OBJ, 3D Studio, Collada DAE, Flash 3D, Google Earth KMZ formats, as well as C4D objects with the Maxon C4D plugin).
When painting on the model there are two ways to start, one is on the model itself, the other is on the mesh. Photoshop CC has the ability to open the model’s mesh by double clicking it. The layers panel will need to be opened and you should see an entry under the Diffuse section of the layer properties (if there isn’t one then one will need to be created by choosing Menu Item / 3D / Generate UVs). If you hold the cursor pointer over this layer item, Photoshop CC will show you preview. Double clicking this item will open up the mesh in a separate window. Once you have this open you may want to have both windows open at the same time, you can do this by choosing Menu Item / Window / Arrange / Tile All Vertically (2 up Vertical will work just as well).
At this point you should see something similar to the following.
Photoshop CC is now able to track the brush painter across both panels, if you move the brush over the model you will see cross hairs appear over the mesh and viva versa, this is a great way to track where you are painting. You can also zoom into either of the documents for close work.
The combo boxes highlighted in Red allow you to paint different elements of the model.
By default you’ll be painting on the Diffuse element, but you can change this when you need to. For example you want want to paint on the Bump map.
If the element does not exist when you start the paint, Photoshop CC will tell you that it does not and help you create it. You can see below that when I try to paint on the Bump map, it doesn’t exist and the warning dialog is displayed.
Pressing OK will take you to the new canvas dialog box (just make sure that the bit depth is the same as the 3D model in this case)
This method of painting in Photoshop CC is called Texture painting, you can still use the older Projection painting as well by changing the mode in the paint system selector.
Before we start painting, you need to make sure that the bit depth of each object is the same, you are able to change the bit depth under the Menu Item / Image Mode / 8 bit / 16 bit or 32 bit, otherwise you will encounter an issue when you start to paint.
To paint, make sure that the brush in Photoshop CC is selected (you can use the B key to do this, there are multiple entries for the B key, so you will just need to make sure that the correct one is selected (highlighted Red below)).
In it’s most simplest form, painting requires that you select a foreground colour from the colour swatches panel (foreground/background colours are shown in the Photoshop hud usually under the tools, (highlighted Red below)). Pressing the switcher icon (top left of the red box) or the ‘X’ key to swap foreground to background etc, and selecting a new colour from the swatch or colour picker will populate the foreground). The ‘D’ key is also handy to reset the foreground and background to black and white.
Don’t forget that Kuler (kuler.adobe.com) is a great way to experiment with new colours or by using the Kuler iPhone app you can create colours from your smart phone and it’s free for everyone, but also part of Creative Cloud.
There is more of a deeper dive on Kuler in a previous post.
To paint on the object, I am going to use some colours that I took using Kuler on my iPhone a while ago, whist in the Purbecks (in the UK), and downloaded (highlighted Red below) as an .ASE file into Photoshop (you can download this from my Creative Cloud share here).
To install into Photoshop, just open the Swatches panel and load new swatch or double click on the downloaded .ASE file.
As a painting decision, I am going to paint the 3D objects Pupils black, the eyelids dark green the the body a lighter green. For more control I am using my Wacom Intuos Tablet as opposed to a mouse, a Wacom Cintiq is even better.
To demonstrate this I have created a very short (3 minute) video that shows how it all works. Enjoy.