Ground Plane

The ground plane is a procedurally created item that generates a flat plane based on a user-defined size. In order to apply surfacing to a ground plane (since there is no actual geometry that you can select and tag), you need to employ an item mask.

Note: Since the ground plane is a volumetric effect, it does not render as quickly as geometry would.

Adding a Ground Plane

To add a ground plane item, go to the Items list on the right side of the screen and click Add Item, then select Volumes > Ground Plane option.

In order to apply any surfacing to the plane, you need to create an item mask. Right-click on the item layer in the Items list to open the contextual menu, and select Create Item Mask. This creates a Material Group Item with the ground plane item specified in its grouping options. Now any textures added into this group apply exclusively to the ground plane (the sample above has a checkerboard texture applied). For more information on adding and working with Shader Tree layers, see Shader Tree.

Transform Properties

Name	This displays the current item's name. You may change it by clicking the current name and typing a new name.
Position XYZ	Specify to position the item numerically in XYZ space. Position transforms originate from the Center position.
Rotation XYZ	Specify to set the rotation of the item numerically. Rotation transforms originate from the Center position.
Order	Sets the order that Modo applies rotations to the falloff item. By changing the order that Modo applies rotations you can sometimes reduce or eliminate gimbal lock.
Scale XYZ	Sets the size of the item numerically. Scale transforms originate from the Center position.
Reset	Resets the selected transform values to (0,0,0) and returns the items back to their default state.
Zero	Resets the selected transform property value to 0 and leaves the Center position and Item position intact.
Add	Use to add the selected set of transforms to the Channel list while keeping the default 0,0,0 values. (Keeping the default values is necessary for Referencing. To be able to override a channel, it must first exist.) Note: Transform items are the channel groups associated with an item that store its transform values. These transform values control an item's position, rotation, or scale. By default, new items do not have any transform items associated with them (although they are visible within the Properties panel). Add only the necessary transforms on an as-needed basis to reduce scene overhead. If you don't use the Add function (as given here), you can transform the target item with one of the various transform tools (or by editing the values). When you do so, Modo automatically adds the transform item to the Channels viewport list.

Ground Plane Properties

Size	Determines the overall dimensions of the plane as a square (width and depth are the same).
Ground	This option toggles the rendering of the ground plane itself. When enabled, Modo draws the plane, when disabled, it doesn't.
Clipping	When this option is enabled, any geometry above the plane is clipped (doesn't render). The clipped areas take on the surfacing of the plane itself.
Fog	Renders a Ground Fog effect when enabled.
Fog Height	Determines the maximum level for the fog effect offset the height distance from the plane. The fog is thickest at the ground level, based on the Density value, attenuating up to the Fog Height value.
Near Clip	Determines the closest point to the camera that the fog effect renders.
Far Clip	Determines the furthest point from the camera that the fog effect renders.
Density	Determines the overall thickness or opacity of the fog effect.
Sample Rate	Determines the quality of the sampling of the fog effect, high values produce cleaner results at the expense of longer render times.

Note: Because of its procedural nature, neither bump maps, nor displacement maps render properly on a ground plane. For those you need to use an actual geometry plane.