Mari 4.6v4 docs:

Project Controls toolbar

The Project Controls toolbar displays a set of four tools:

• Selection - lets you switch between three selection modes (objects, patches, and faces) when using the Select tool. See Selecting Objects, Patches, or Faces.

• Default Shaders - displays one of the four default shaders in the Shaders palette and the last-selected user shader: Current Channel, Current Layer and Below, Current Layer, Current Paint Target, and User Shader. Selecting a custom created shader in the Shaders palette won't highlight any of the shaders in the toolbar, but selecting a default shader from either the palette or the toolbar activates the shader and highlights the icon in the toolbar. See Shaders.

• Lighting - lets you change the lighting on the object. You can select one of the five lighting modes: Flat, Basic, Basic with Shadows, Full, or Full with Shadows. By default, lighting is relative to the scene, not the view. You can set the individual lights to move the view. Mari saves custom lighting with the project. If you need the same lights in another project, you need to set them up separately. See Configuring the Lighting.

• Paint Buffer Symmetry - displays the four Mirror Painting modes for the Paint Buffer Symmetry functionality. See Paint Buffer Symmetry.

• Mirror Projection - displays the four Mirror Projecting modes for the Mirror Projection functionality. See Mirror Projection.

Project Controls Toolbar Controls

Tool	Control	Type	What it does	Notes
		button	Selects whole objects.
		button	Selects patches on objects.	You can hold down Shift to add to the selection, Ctrl/Cmd to remove from the selection, and (Windows) or Shift+Cmd to intersect the selection.
		button	Selects areas on objects.	You can hold down Shift to add to the selection, Ctrl/Cmd to remove from the selection, and (Windows) or Shift+Cmd to intersect the selection. When using the Select tool, double-click on the face of the model to create a smart selection based on the settings in the Type dropdown menu.
		button	Selects the default Current Channel shader from the Shaders palette and displays only the paint in the current channel.
		button	Selects the default Current Layer and Below shader from the Shaders palette and displays only the paint in the current layer stack.
		button	Selects the default Current Layer shader from the Shaders palette and displays only the paint in the current layer.
		button	Selects the default Current Paint Target shader from the Shaders palette and displays only the paint of the currently selected target.
		button	Select the User Shader, which is the last selected shader you added to the Shaders palette.
		button	Set the lighting on the object to "Flat".	In this mode, the position of the lights has no effect.
		button	Set the lighting on the object to "Basic".	In this mode, you can move lights around on the canvas or make fine adjustments to lighting using the Lights Palette.
		button	Set the lighting on the object to "Basic with Shadows" - basic lighting with diffuse lighting, as well as shadows.	To enable shadow processing, in the Mari Preferences Dialog, in the GPU tab, enable the Shadow Maps > Allowed checkbox. By default this preference is disabled.
		button	Set the lighting on the object to "Full".	In this mode, you can move lights around on the canvas or make fine adjustments to lighting using the Lights Palette.
		button	Set the lighting on the object to "Full with Shadows" - full lighting with diffuse and specular lighting, as well as shadows.	To enable shadow processing, in the Mari Preferences Dialog, in the GPU tab, enable the Shadow Maps > Allowed checkbox. By default this preference is disabled.
		button	This is the default setting. Mirror projection is disabled.
		button	With Mirror Projecting X selected, the mirror line appears vertically. Paint strokes created on either the left or right side of the mirror plane project the same strokes on the other side.
		button	With Mirror Projecting Y selected, the mirror line appears horizontally. Paint strokes created either on top or under the mirror plane project the same strokes on the other side.
		button	With Mirror Projecting Z selected, the mirror line appears vertically intersecting the profile of the asset. Paint strokes created either at the front or back of the mirror plane are projected on the opposite side of the geometry.
		button	This is the default setting. When mirroring is disabled, the paint buffer acts as normal and the paint strokes are not mirrored.
		button	Mirroring left and right splits the paint buffer down the center vertically. Any paint strokes made on either the left or right side of the divider are mirrored on the opposite side.	This applies to paint strokes only.
		button	Mirroring top and bottom splits the paint buffer down the center horizontally. Any paint strokes made on either the top or bottom of the divider are mirrored on the opposite side.	This applies to paint strokes only.
		button	Mirroring four ways splits the paint buffer into quarters around the center of the canvas. Any paint strokes made in one of the quadrants are mirrored in the other three.	This applies to paint strokes only.