Table of Contents

The Surface Scattering Tab is part of the Chaos Scatter parameters.


Surface Scattering


Distribution mode – Allows selecting between different distribution modes.

Random – Scatters randomly on all mesh and closed spline distribution objects.
Uv – Uses the distribution objects' UVW mapping to scatter the instances in regular patterns.

The options from Count to Distribution are only available when the Distribution mode is set to Random.

Count – Defines an exact number of instances to scatter overall. When the Per square option is enabled, scatters instances per area, defined by density. The number is always limited by the Config Max. limit option.

Per square – When enabled, the number of instances to scatter is defined by density (Count per square having the given edge length). The number of instances is always limited by the Config Max. limit option. The specified value is the edge length of a square, which defines an area for computing the scatter density.

Distribution – Specifies a texture map or shader used for instance distribution. White areas of the texture are treated as maximum density, and black areas are treated as areas with no instances.

The options from Pattern to Lock V are available only when the Distribution mode is set to UV.

Pattern – Allows to select between different distribution patterns.

Grid – Rectangular grid.
RunningGrid – Rectangular grid with every other row offset by half of the grid spacing.
HexagonalGrid – Hexagonal point arrangement.

Use planar mapping – When enabled, simple planar UVW mapping is applied to the distribution object and used instead of its existing UVW channel.

Spacing U – Scales the pattern in the U axis - 100% spacing makes the pattern occupy the whole 0-1 UV space; with 50% spacing, the pattern gets repeated 2 times in U.

Spacing V – Scales the pattern in the V axis - 100% spacing makes the pattern occupy the whole 0-1 UV space; with 50% spacing, the pattern gets repeated 2 times in V.

Jitter U – Randomly jitters each instance in the U axis, with 0% being entirely deterministic placement (no jitter) and 100% being entirely random placement.

Jitter V – Randomly jitters each instance in the V axis, with 0% being entirely deterministic placement (no jitter) and 100% being entirely random placement.

Offset U – Offsets the pattern in the U axis. Each 100% added or subtracted moves the pattern by one entire repetition - which means that, e.g., 0% and 100% offsets yield the same result.

Offset V – Offsets the pattern in the V axis. Each 100% added or subtracted moves the pattern by one entire repetition - which means that, e.g., 0% and 100% offsets yield the same result.

Lock V – Locks the V coordinate for Spacing, Jitter, and Offset to the same value as the U coordinate.



Slope


Enabled – Toggles the slope parameter on and off. Slope allows scattered geometry to be removed based on the angle of the underlying geometry. If an area is outside the range defined in this rollout, geometry is removed from it. This is great for realistically simulating steep mountains, as there is no greenery on the steepest slopes.

Up mode – Allows selecting between different modes for the up axis. See the Slope Up mode example.

Local – The up vector of each individual distribute-on object is used to define the slope limitation.
World – The world Y-axis up vector is used for all distribute-on objects to define the slope limitation.

From/To – These values set the range of angles, measured in degrees, between either the Local or the World up vector and the surface normal. Determines how steep the surface can be before instances are filtered out. Instances scattered outside of this range are erased. See the Slope example.





Example: Slope

The Slope effect removes scattered objects depending on the angle of the underlying geometry. Slope can be used to remove objects from steep areas and shallow areas, using the From and To parameters.


Slope = Disabled

Slope From = 0° Slope To = 45°

Slope From = 0° Slope To = 20°

Slope From = 5° Slope To = 20°





Example: Slope Up mode

The Local Up mode takes the normals of the Distribute On object and uses them to determine which way is up. In this example, the Slope is set FromTo 45°.


local Before image
world After image


Altitude


Enabled – Toggles the altitude parameter on and off. Altitude defines a height range (in cm) for the scattered geometry to distribute on. Any geometry outside the range is filtered out. See the example for more.

Coord. space – Determines whether Local or World coordinate space is used for the height range.

From/To – Defines the minimum and maximum height of the range. Any geometry below or above this is filtered out.

Falloff – Smooths out the altitude cutoff, allowing for a gradual fade-out. Use the curve control to define the transition. For further controls, open the menu. Additional points can be added by holding Ctrl and left-clicking anywhere on the curve. See the example or more.





Example: Altitude

In this example, the Altitude and the Altitude Falloff parameters are showcased. Setting the Altitude To parameter to 500cm cuts off the scattered forest at that height. Adding Falloff thins out the forest at the lower point of the curve.


Altitude = Disabled

Altitude From 0cm To 500cm

Altitude Falloff = increasing curve

Altitude Falloff = decreasing curve





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Camera Clipping Tab


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Transformations Tab