Regardless of the application you’re using, digital painters are quite comfortable with using a layer-based approach in creating their artwork. It allows for a great deal of flexibility and organization when it comes to separating the different pieces or components of your art. Long gone is the day when a painter worked on a canvas. Inside of today's applications, this would be the equivalent of painting everything on a single layer. Painting textures inside of MARI after the release of v2.0 is now no different. Previously, artwork was painted onto channels inside of your project, and those channels were plugged into a shader to display the texture information. With the inclusion of layers inside of MARI, it really wouldn't be fair to say that it’s just like other applications now. That wouldn't do this wonderful new feature justice.

What Is a Stack?

To understand MARI's implementation of layers, you’ll need to understand the concept of a stack. Each channel inside of a MARI project now includes its own layer stack. Once opened and explored, you’ll quickly find that each of these layer stacks is very similar in setup to other layer-based applications. All of the features you’re accustomed to seeing are there: the ability to create, delete and organize layers with groups, not to mention the incredibly useful features like layer masks and adjustment layers. So the idea of a stack is really pretty simple, right? It's just a collection of layers attached to each channel you create in your project. Oh, but wait. There’s more—much more.

Adjusting Stack Perception

If stack was a term that only referred to a collection of paintable layers then why should it be a term at all? The reality is that stacks are a core part of the layer-based workflow introduced with MARI 2.0, and they don't just apply to paint layers. Let's talk for just a moment about adjustment layers and what we are accustomed to them doing. If you've never worked in any other layer-based application besides Photoshop, you at least have a pretty solid idea of how they perform there. They change the look of the layers underneath them or the layer that they’re clipped to, depending on what type of adjustment they’re performing. Inside of MARI an adjustment layer functions in very much the same way. Only instead of having a large number of adjustment layers clipped to a single layer they’re affecting, MARI implements a stack. In this case, the stack would be, again, a collection of layers only this time they’re adjustment layers.

Stack Those Masks

What about masks? Aren't they just a form of painted data that’s grayscale and contained on a type layer? What, you've never thought of a mask like that? Well the good people over at The Foundry did. If you want a more traditional layer mask experience, it's surely available to you. If, however, you decide that you'd like to be able to build your mask using multiple layers, adjusting things like layer opacity or blend mode as you go, then you’ll love using mask stacks. What becomes incredibly powerful about mask stacks is the ability to create your mask from different types of layers. For example, you could combine a procedural layer with hand-painted information and image data to create your mask. Having the ability to use a stack of layers to create your mask really opens up so many possibilities!

Combining Stacks and Sharing Layers

With three different types of stacks, MARI's layer-based workflow suddenly isn't exactly like other applications. There’s a good deal more flexibility and power here. What would happen if you used an adjustment stack inside of a mask stack? Or maybe it's the exact opposite. Maybe you need to use multiple layers to define a mask for one of the adjustments inside of your adjustment stack. These stacks are nestable within each other almost to the point where it can be mind boggling. Don't let that frighten you though. Another feature introduced with MARI 2.0 is the ability to share layers between layer stacks and channels. This feature becomes extremely useful when you’re working inside either an adjustment stack or a mask stack. If multiple layers, each containing a different piece of the diffuse texture, need to be masked in exactly the same way, then you can share layers between their mask stacks. Any changes made to one layer will be made within the other mask stacks.   When it comes to MARI's implementation of layer-based painting, flexibility is the name of the game. Being able to stack your adjustments and masks may seem a little confusing at first, but give it some time. After working with these new features, it won't take long before you really begin to deploy them within your own projects in ways that not only save you time, but also make your projects lighter and more manageable. If you'd like to see these different types of stacks in action, make sure and check out our MARI tutorials, specifically the Your First Day with MARI tutorial and our Introduction to MARI 2.0 tutorial. Then feel free to jump into any tutorial created in MARI v2.0 or later, as these new features are something you’ll want to build your painting workflows around.