Areas

In this panel we define the regions in which the items are created.

The areas are not available when working on Custom Edit mode or using UV Surfaces.

There are 4 types of areas: Splines, Objects, Painting and Surfaces. Depending of its type, an area may work in two modes: Include (creating items within the region), or Exclude (the items are removed from the area).

The order in the list is significative: the exclusion areas have effect only over the areas below it.

The first three buttons ( ) add a new area of type Spline, Object and Painting respectively. Other buttons of the toolbar are:

Removes the selected area.

Add multiple areas from a list of splines or objects selected from the scene.

The Up/Down arrows modifies the order of the items in the list.

You must be careful to not overlap multiple "Include" areas. In this case, the items are duplicated in the overlapped positions. This issue is not detectable visually, but you would get strange results in the render because the overlapped faces.

Selecting an item from the list will change the values of the "Properties" parameters. Some properties are common to all types of areas, while other are exclusive:

Spline Areas

Allows you to use a spline (closed or open) as area.

Include/Exclude

Defines if the area is used to create items within the region defined by the spline (Include) or as an exclusion zone (Exclude). The exclusion areas have effect only over the areas below it in the list.

Thickness

Used only with open splines, defines the distance around the spline which is considered as the area.

Convert to Paint

Converts the selected Spline area to a Paint type (see painting areas below for details).

Object Areas

Lets you to use any geometric object as excluding area, removing the items from the region occupied by the object.

This type of area is optimized to work with high-poly objects in real time. Internally it works painting over a bitmap the mesh of the surface (as seen from the top view), and computing the distances to the items.

You also can assign groups as valid objects, but use only groups of geometric objects which are closed together. If you need to use multiple objects scattered along a wide zone, assign each one of them in a separated area.

Top Limit

Use it to define an upper limit on the mesh, above which the exclusion area has no effect. This limit is typically used with objects that are wider at the top than at the bottom.

Map Size

Defines the size of the internal bitmap (512 by default). You may increase it to improve the precision of the excluding process (typically when working with very large objects).

Forest Areas

Similarly to the Object Areas, lets you to use any Forest object from the scene as excluding area.

A typical use would be to remove or create a separate grass region around a group of trees, which are created using a Forest object (see the video).

There are two modes to compute the excluding region:

• Sphere. Uses a virtual bounding-sphere that surrounds each item. The size of the sphere may be scaled using the "Scale" parameter of the area, or modifying the "Collision Radius" parameter in the Geometry List of the excluding Forest.
• Mesh: Uses the full geometry of each item. This mode may be slower, specially using heavy geometries, but more precise.

Painting Areas

Add or remove items painting directly over the terrain. They can be used as "Include" or "Exclude" areas. The painting areas always require a XY Surface to work.

Paint buttons

Use the first two buttons to switch between the Paint and Erase modes. The last button is used to set the brush settings.

The Paint and Erase modes let you modify the region occupied by the area, but the result (if the items are added or removed) depends if the area is working as "Include" or "Exclude".

Preview Falloff

Use this checkbox to disable the falloff while painting (enabled by default).

Convert to Spline

To difference to other painting tools, the Painting areas are editable and can be converted to splines and back. Use this button to convert it to a Spline type.

Surfaces Area

This type of area is completely different from the others: an unique "Surfaces Area" item is shown automatically in the list, if there is at least a Surface assigned to Forest.

It uses all the XY Surfaces as "Include" regions, scattering items along the terrain. This area can be turned off, but not deleted.

If you want to add items over a specific region using an "Include" area, but instead the full terrain is filled with items, probably the "Surfaces Areas" is on. In this case, Forest creates duplicated items for all the overlapped "Include" areas, which is not desirable and would generate unexpected results at render.

Common Properties

The following properties are available for all types of areas.

Override Distribution Map

Modifies the Distribution Map for the selected area. You can assign a custom map and adjust the Scale and Threshold values.

Select Models

Lets you to select a subset of models from the Geometry List, and use them for the selected area, instead the full list.

Affect Falloff

Adjusts the strength of the falloff curves (Density and Scale). Setting it to zero, disables the falloff effects completely.

Boundary Checking

This option defines the mode used by Forest to check if an item is within or outside the Area spline: 'Point', checks only the item's position, or 'Size', uses the item's width and its collision radius.

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Spline Falloff

In some scenes it may be useful to modify the items near the edges of the area. Here we can define density and scale curves for area distance. There are separate ranges for Include and Exclude.

The default range values are 0, that will not create any falloff effect. So, to use this feature, you must enable the "Active" checkbox and set a range value greater than 0.