Substance Painter - How to import and map a texture with transparency as a mask
The 3D Model used in this tutorial: on-off power switch
In this video we will see how to import and map a mask to apply one Material on another in Substance Painter 2019, in particular using a PNG image with white symbols on a transparent background and the UV MAP of the object.
First of all, let's create a new Substance Painter project, specifying the template to use (“PBR - Metallic”), the resolution of the project (“2K”, here), and, of course, the 3D model we want to use.
Now, let's import the Image Texture into the project, in this way: in the “File” menu, choose “Import Resources”, then add the image by clicking on "Add resources" in the window that will appear.
Let's change the data type from "undefined" to "alpha", choose to import the texture in the “current session” and click on “Import”.
To show you how to apply the Material on another only in the points specified by the mask, I'm providing a basic material to the object.
I'm using "Black Slate", which I am dragging from the “Materials” tab of the “Shelf” window into “Layers”.
For the material of the symbols, I want to use the "Resin Epoxy" material, but with an increased “Roughness”, so I drag it from Materials in “Layers”, positioning it ABOVE "Black Slate" (so as to completely cover it), then I change the “Resin Roughness” value raising it from 0.24 to 0.6.
In order to use the PNG Texture with transparency as a mask to apply the "Resin Epoxy" material only in one part of the switch, right-click on "Resin Epoxy" in “Layers” and select "Add bitmap mask", then type the name of the image to use and select it.
The mask is a white image on a transparent background, so it will apply the material it is associated with only in the points where it is white; we must therefore place the mask on the object.
Let's proceed in this way: click on the "Fill" box of the new mask, in “Layers”, then change the way the window is displayed from “3D” to “3D | 2D”.
To lock the proportions of the Texture while we resize and move it in the 2D window, we hold down the SHIFT key while we click and drag on one of the corners of the mask.
We note that the mask is repeated on several parts of the object; to apply it only to the square visible in the 2D window, select the Fill element of the Mask and change "UV Wrap" from "Repeat" to "None", in the "Properties - Fill" tab.
Let's finish placing and resizing the mask on the UV mapping of the object, in the “2D” window, until the desired result is obtained.
Well, we're done! Note that, since "Resin Epoxy" is a full-fledged material, you can activate or deactivate some of its PBR channels, in the Material section of the “Properties – Fill” tab, to decide which effects to use and which to take instead from the underlying materials ("Black slate", here).
That's all for this tutorial! As usual, I invite you to express doubts, questions or requests for clarification in the comments to the video!