com.jme3.bullet.collision.shapes

Class HeightfieldCollisionShape

java.lang.Object

com.jme3.bullet.collision.shapes.CollisionShape

com.jme3.bullet.collision.shapes.HeightfieldCollisionShape

All Implemented Interfaces:

Savable

public class HeightfieldCollisionShape
extends CollisionShape

A terrain collision shape based on Bullet's btHeightfieldTerrainShape.

This is much more efficient than a regular mesh, but it has a couple limitations:

• No rotation or translation.
• The collision bounding box must be centered on (0,0,0) with the height above and below the X-Z plane being equal on either side. If not, the whole collision box is shifted vertically and objects won't collide properly.

Field Summary

Fields

Modifier and Type	Field and Description
protected java.nio.ByteBuffer	bbuf buffer for passing height data to Bullet
protected boolean	flipQuadEdges
protected float[]	heightfieldData array of heightfield samples
protected float	heightScale
protected int	heightStickLength number of columns in the heightfield (>1)
protected int	heightStickWidth number of rows in the heightfield (>1)
protected float	maxHeight
protected float	minHeight
protected int	upAxis index of the height axis (0→X, 1→Y, 2→Z)

Fields inherited from class com.jme3.bullet.collision.shapes.CollisionShape

margin, objectId, scale

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	HeightfieldCollisionShape() No-argument constructor needed by SavableClassUtil.
	HeightfieldCollisionShape(float[] heightmap) Instantiate a new shape for the specified height map.
	HeightfieldCollisionShape(float[] heightmap, Vector3f scale) Instantiate a new shape for the specified height map and scale vector.

Method Summary

Modifier and Type	Method and Description
protected void	createCollisionHeightfield(float[] heightmap, Vector3f worldScale)
Mesh	createJmeMesh() Does nothing.
protected void	createShape() Instantiate the configured shape in Bullet.
void	read(JmeImporter im) De-serialize this shape, for example when loading from a J3O file.
void	write(JmeExporter ex) Serialize this shape, for example when saving to a J3O file.

Methods inherited from class com.jme3.bullet.collision.shapes.CollisionShape

finalize, getDefaultMargin, getMargin, getObjectId, getScale, isNonMoving, setDefaultMargin, setMargin, setObjectId, setScale

Methods inherited from class java.lang.Object

clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

heightStickWidth

protected int heightStickWidth

number of rows in the heightfield (>1)

heightStickLength

protected int heightStickLength

number of columns in the heightfield (>1)

heightfieldData

protected float[] heightfieldData

array of heightfield samples

heightScale

protected float heightScale

minHeight

protected float minHeight

maxHeight

protected float maxHeight

upAxis

protected int upAxis

index of the height axis (0→X, 1→Y, 2→Z)

flipQuadEdges

protected boolean flipQuadEdges

bbuf

protected java.nio.ByteBuffer bbuf

buffer for passing height data to Bullet

A Java reference must persist after createShape() completes, or else the buffer might get garbage collected.

Constructor Detail

HeightfieldCollisionShape

protected HeightfieldCollisionShape()

No-argument constructor needed by SavableClassUtil. Do not invoke directly!

HeightfieldCollisionShape

public HeightfieldCollisionShape(float[] heightmap)

Instantiate a new shape for the specified height map.

Parameters:

heightmap - (not null, length≥4, length a perfect square)

HeightfieldCollisionShape

public HeightfieldCollisionShape(float[] heightmap,
                                 Vector3f scale)

Instantiate a new shape for the specified height map and scale vector.

Parameters:

heightmap - (not null, length≥4, length a perfect square)

scale - (not null, no negative component, unaffected, default=1,1,1)

Method Detail

createCollisionHeightfield

protected void createCollisionHeightfield(float[] heightmap,
                                          Vector3f worldScale)

createShape

protected void createShape()

Instantiate the configured shape in Bullet.

createJmeMesh

public Mesh createJmeMesh()

Does nothing.

Returns:

null

write

public void write(JmeExporter ex)
           throws java.io.IOException

Serialize this shape, for example when saving to a J3O file.

Specified by:

write in interface Savable

Overrides:

write in class CollisionShape

Parameters:

ex - exporter (not null)

Throws:

java.io.IOException - from exporter

read

public void read(JmeImporter im)
          throws java.io.IOException

De-serialize this shape, for example when loading from a J3O file.

Specified by:

read in interface Savable

Overrides:

read in class CollisionShape

Parameters:

im - importer (not null)

Throws:

java.io.IOException - from importer