Create Your Own Brushes
You can provide your own brushes in the Run Settings. The algorithm expects you to provide it with exactly four brushes in one file. The image file needs to contain four channels RGBA. Each channel holds one the brush textures.
This guide will be focused around Photoshop, although it would work for any image editing software. Let's say instead of an artistic brush, we wanted to paint the scene with the Unity Logo.
In your project files head to Assets/Texture. There you can open any of the PSD files I have created. A typical brush would look something like this:
As you can see, several channels are overlapped on top of each other. If you open the Channels window in photo shop, you can see this better.
If the Alpha is not there, you need to create it yourself. If you select any of these channels, you would be painting only on those and all the others will be blended out. For example:
So far so good. To replace the all the brushes, I first select each channel, fill it up with the color black, then copy paste the white Unity logo on those channels.
Remember that the black in each channel acts as transparency. Black pixels are transparent, white pixels are fully opaque.
Then save as the file in a new PSD in the same location. Before you can assign this to your setting, make sure you turn off the sRGB bool in the property settings of the texture.
