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Force

The properties on force objects control how forces affect the model and the scene.

Note: Forces operate only on Generators or Nodes where the force is enabled in the “Forces” property group.

Force

The properties in this group set the basic functionality of force objects.

Enabled

Use this property to toggle the force's influence on model computation. Disabling a mesh force will stop it from influencing the model but it will not take it out of the model if it is set to be included (see “Include in Model,” below).

Type

Sets the type of force.

Strength

This value controls how much the force influences the model. This number is multiplied by the value of the force properties on each generator before being applied to the model.

Color

Sets the color of the force indicator in the Tree Window.

Indicator Scale

Sets the size of the icon used to represent the force in the Tree Window. This property has no effect on the size of actual mesh forces.

Mesh

These properties control the behavior of mesh forces. Set the “Type” property above to “Mesh” to make a force act as a force mesh.

Include in Model

Enable this property to have the mesh exported as part of the model. With this property disabled, the mesh will be used to interact with the model but it will not be included in exports.

Mesh

Specifies a named mesh asset.

Force action

Specifies how the mesh surface should influence branch spines from the following options:

Avoid Spines are repelled by the closest spot on the surface of the mesh.
Attract Spines are pulled towards the closest spot on the surface of the mesh.
None No action is applied to the spines.
Collide Action

Specifies what happens when a branch spine collides with the mesh surface. You may choose from the following options:

None No action is taken (spines will go through the mesh).
Obstruct Spines are blocked by the surface of the mesh and “crawl” over it, attempting to grow in their original direction.
Prune Spines are broken when they collide with the mesh.
Stop Spines are considered fully grown where they hit the mesh. They will be shorter than intended but all of the profile curves will cover the full length of the spine.
Keep Action

Specifies what happens to spines that are using this mesh from the following options:

All All nodes will be kept regardless whether they collide with the mesh or not.
Hits Only nodes that collide with this mesh will be kept (if this force is enabled on the generator). All others will be destroyed.
Misses Only nodes that do not collide with this mesh force will be kept (if this force is enabled on the generator). All others will be destroyed.
Obstruction Distance

Sets the distance from the base of each spine node where obstruction by the mesh force is prohibited. It is sometimes desirable to refrain from obstructing the very base of branches so that they are able to begin their growth without being immediately redirected by mesh forces.

Max Iterations

When a mesh collision is detected, this property determines how many attempts are made to continue on without going through the mesh. More iterations means a better chance of finding a route at the expense of slower computation times.

Max Angle

Specifies the maximum amount a spine can bend to try to get around the mesh.

Give up Action

Once all of the iterations have failed for a spine that has collided with the mesh, this property specifies what action to take from the following options:

None No action is taken, the spine goes through the mesh.
Prune Spines that cannot escape will be pruned at the collision point.
Destroy The spine will be removed.
Ambient Occluder

When the mesh is not being included in the model, check this property to allow the mesh to contribute to ambient occlusion computations.

Level of Detail

Specifies which mesh LOD, if available, is used for the current LOD state.

Note: LOD meshes must be assigned to the mesh assets for this property to work.

Material

The properties in this group control the appearance of the force mesh.

Material

Specifies a named material from the Mesh Asset Bar.

Color

Specifies what color is used to render the mesh when no material has been assigned.

Lightmap

Controls this mesh's influence on the lightmap in versions where lightmap UVs are computed.

Scale

Use this value to take up more or less space in the lightmap.

Attenuation

Causes the force's influence to taper off as the spine gets farther away from the location of the force.

Type

Specifies the type of attenuation from the following options:

None The force has an equal effect on the entire model regardless of its location in the scene.
Linear The force falls off linearly over the distance specified below.
Quadratic The force falls off according to the square of the distance from the source.
Hard The force effect goes to zero outside the distance specified below.
Distance

This value sets distance around the force where attenuation is applied.

Falloff Distance

Sets the distance from the edge of the attenuation towards the force location at which attenuation begins.

Indicator

Selects when the attenuation indicator is displayed from the following options:

Selected Only display the indicator when the force is selected.
Always Always show the indicator.
Never Never display the attenuation indicator.

Container Forces

The properties in this group allow you to specify mesh forces to be used to designate the area of effect for this force. Use these properties to designate regions where forces work based on mesh assets.

Include

Type the name of a mesh force in this property. That mesh will be used to indicate the only region where this force is applied.

Exclude

Type the name of a mesh force in this property. That mesh will be used to indicate the region where this force will not be applied.

Animation

Forces can be animated over time and exported as part of a sequence for VFX applications. Use the properties in this group to control the animation.

Note: Only the force's strength can be animated – its position cannot be animated.
Start Frame

Specifies the frame at which the animation starts.

Duration

Sets how many frames the animation lasts.

Profile

Controls the animation, as follows: The left hand side of the curve corresponds to the percentage of the force applied at the start frame. The right hand side corresponds to the percentage of the force applied at the end of the animation duration.

Growth

When using animated growth, controls the strength of the force over the life cycle of the growth animation.

Lifetime %

Controls the strength of the force over the duration of the growth animation. The left hand side of the curve corresponds to the percentage of the force applied at the start of the growth animation. The right hand side corresponds to the percentage of the force applied at the end of the growth animation.

Transform

The properties in this group control the position and orientation of the force. They are set automatically when you use the transform gizmo to move and orient the force.

Translation

X, Y, Z

Sets the position of the force object.

Reset translation

Positions the force at the origin.

Rotation

Axis X, Axis Y, Axis Z

Specifies the vector around which the force is rotated.

Angle

Specifies how much the force is rotated around the axis.

Reset rotation

Resets the rotation back to the default settings.

Scale

X, Y, Z

Sets the scale of the force object on each axis.

Uniform

When checked, the X, Y, and Z scales are set to the same value as to not distort the shape.

Reset Scaling

Sets the scale values back to 1.0.