Package com.jme3.terrain.geomipmap

Class TerrainPatch

java.lang.Object
com.jme3.scene.Spatial
com.jme3.scene.Geometry
com.jme3.terrain.geomipmap.TerrainPatch
All Implemented Interfaces:
com.jme3.anim.util.HasLocalTransform, com.jme3.asset.CloneableSmartAsset, com.jme3.collision.Collidable, com.jme3.export.Savable, com.jme3.util.clone.JmeCloneable, Cloneable
public class TerrainPatch extends com.jme3.scene.Geometry
A terrain patch is a leaf in the terrain quad tree. It has a mesh that can change levels of detail (LOD) whenever the view point, or camera, changes. The actual terrain mesh is created by the LODGeomap class. That uses a geo-mipmapping algorithm to change the index buffer of the mesh. The mesh is a triangle strip. In wireframe mode you might notice some strange lines, these are degenerate triangles generated by the geoMipMap algorithm and can be ignored. The video card removes them at almost no cost. Each patch needs to know its neighbour's LOD so it can seam its edges with them, in case the neighbour has a different LOD. If this doesn't happen, you will see gaps. The LOD value is most detailed at zero. It gets less detailed the higher the LOD value until you reach maxLod, which is a mathematical limit on the number of times the 'size' of the patch can be divided by two. However, there is a -1 to that for now until I add in a custom index buffer calculation for that max level, the current algorithm does not go that far. You can supply a LodThresholdCalculator for use in determining when the LOD should change. Its API will no doubt change in the near future. Right now it defaults to just changing LOD every two patch sizes. So if a patch has a size of 65, then the LOD changes every 130 units away.
Author:
Brent Owens

  • Nested Class Summary

    Nested classes/interfaces inherited from class com.jme3.scene.Spatial

    com.jme3.scene.Spatial.BatchHint, com.jme3.scene.Spatial.CullHint, com.jme3.scene.Spatial.DFSMode

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    protected TerrainPatch
    bottomNeighbour
     
    protected LODGeomap
    geomap
     
    protected TerrainPatch
    leftNeighbour
     
    protected int
    lod
     
    protected int
    lodBottom
     
    protected float[]
    lodEntropy
     
    protected int
    lodLeft
     
    protected int
    lodRight
     
    protected int
    lodTop
     
    protected com.jme3.math.Vector2f
    offset
     
    protected float
    offsetAmount
     
    protected int
    previousLod
     
    protected short
    quadrant
     
    protected TerrainPatch
    rightNeighbour
     
    protected boolean
    searchedForNeighboursAlready
     
    protected int
    size
     
    protected com.jme3.math.Vector3f
    stepScale
     
    protected TerrainPatch
    topNeighbour
     
    protected int
    totalSize
     
    protected com.jme3.math.Vector3f
    worldScaleCached
     
    protected com.jme3.math.Vector3f
    worldTranslationCached
     

    Fields inherited from class com.jme3.scene.Geometry

    cachedWorldMat, groupNode, ignoreTransform, lodLevel, material, mesh, SAVABLE_VERSION, startIndex

    Fields inherited from class com.jme3.scene.Spatial

    batchHint, controls, cullHint, frustrumIntersects, key, localLights, localOverrides, localTransform, name, parent, queueBucket, queueDistance, refreshFlags, RF_BOUND, RF_CHILD_LIGHTLIST, RF_LIGHTLIST, RF_MATPARAM_OVERRIDE, RF_TRANSFORM, shadowMode, userData, worldBound, worldLights, worldOverrides, worldTransform

  • Constructor Summary

    Constructors
    Constructor
    Description
    TerrainPatch()
     
    TerrainPatch(String name)
     
    TerrainPatch(String name, int size)
     
    TerrainPatch(String name, int size, com.jme3.math.Vector3f stepScale, float[] heightMap, com.jme3.math.Vector3f origin)
    Constructor instantiates a new TerrainPatch object.
    TerrainPatch(String name, int size, com.jme3.math.Vector3f stepScale, float[] heightMap, com.jme3.math.Vector3f origin, int totalSize, com.jme3.math.Vector2f offset, float offsetAmount)
    Constructor instantiates a new TerrainPatch object.

  • Method Summary

    Modifier and Type
    Method
    Description
    protected void
    averageNormalsTangents(com.jme3.math.Vector3f topPoint, com.jme3.math.Vector3f rootPoint, com.jme3.math.Vector3f leftPoint, com.jme3.math.Vector3f bottomPoint, com.jme3.math.Vector3f rightPoint, com.jme3.math.Vector3f normal, com.jme3.math.Vector3f tangent, com.jme3.math.Vector3f binormal)
     
    protected void
    cacheTerrainTransforms()
    Caches the transforms (except rotation) so the LOD calculator, which runs on a separate thread, can access them safely.
    protected void
    clearCaches()
    Removes any references when the terrain is being removed.
    TerrainPatch
    clone()
     
    void
    cloneFields(com.jme3.util.clone.Cloner cloner, Object original)
    Called internally by com.jme3.util.clone.Cloner.
    int
    collideWith(com.jme3.collision.Collidable other, com.jme3.collision.CollisionResults results)
     
    protected void
    ensurePositiveVolumeBBox()
     
    protected void
    fixNormalEdges(TerrainPatch right, TerrainPatch bottom, TerrainPatch top, TerrainPatch left, TerrainPatch bottomRight, TerrainPatch bottomLeft, TerrainPatch topRight, TerrainPatch topLeft)
    Matches the normals along the edge of the patch with the neighbours.
    void
    generateLodEntropies()
    This calculation is slow, so don't use it often.
    com.jme3.math.Triangle[]
    getGridTriangles(float x, float z)
    Get the triangles at the specified grid point.
    protected float
    getHeight(int x, int z, float xm, float zm)
     
    float[]
    getHeightMap()
     
    float
    getHeightmapHeight(float x, float z)
     
    int
    getLod()
     
    protected int
    getLodBottom()
     
    float[]
    getLodEntropies()
     
    protected int
    getLodLeft()
     
    protected int
    getLodRight()
     
    protected int
    getLodTop()
     
    int
    getMaxLod()
    The maximum lod supported by this terrain patch.
    protected com.jme3.math.Vector3f
    getMeshNormal(int x, int z)
     
    com.jme3.math.Vector2f
    getOffset()
    Returns the current offset amount.
    float
    getOffsetAmount()
    Returns the offset amount this terrain patch uses for textures.
    int
    getPreviousLod()
     
    short
    getQuadrant()
     
    int
    getSize()
    Returns the size of this terrain patch.
    com.jme3.math.Vector3f
    getStepScale()
    Returns the step scale that stretches the height map.
    com.jme3.math.Vector2f
    getTex(float x, float z, com.jme3.math.Vector2f store)
     
    int
    getTotalSize()
    Returns the total size of the terrain.
    com.jme3.math.Triangle
    getTriangle(float x, float z)
    Get the triangle of this geometry at the specified local coordinate.
    com.jme3.math.Vector3f
    getWorldScaleCached()
     
    com.jme3.math.Vector3f
    getWorldTranslationCached()
     
    void
    lockMesh()
    Locks the mesh (sets it static) to improve performance.
    void
    read(com.jme3.export.JmeImporter im)
     
    protected void
    reIndexGeometry(HashMap<String,UpdatedTerrainPatch> updated, boolean useVariableLod)
     
    protected void
    setHeight(List<TerrainQuad.LocationHeight> locationHeights, boolean overrideHeight)
     
    void
    setLod(int lod)
     
    protected void
    setLodBottom(int lodBottom)
     
    protected void
    setLodLeft(int lodLeft)
     
    protected void
    setLodRight(int lodRight)
     
    protected void
    setLodTop(int lodTop)
     
    void
    setOffset(com.jme3.math.Vector2f offset)
    Sets the value for the current offset amount to use when building texture coordinates.
    void
    setOffsetAmount(float offsetAmount)
    Sets the offset of this terrain texture map.
    void
    setPreviousLod(int previousLod)
     
    void
    setQuadrant(short quadrant)
     
    void
    setSize(int size)
    Sets the size of this terrain patch.
    void
    setStepScale(com.jme3.math.Vector3f stepScale)
    Sets the step scale of this terrain patch's height map.
    void
    setTotalSize(int totalSize)
    Sets the total size of the terrain .
    void
    unlockMesh()
    Unlocks the mesh (sets it dynamic) to make it editable.
    protected void
    updateNormals()
    Recalculates all normal vectors in this terrain patch.
    protected com.jme3.math.Vector3f
    worldCoordinateToLocal(com.jme3.math.Vector3f loc)
     
    void
    write(com.jme3.export.JmeExporter ex)
     

    Methods inherited from class com.jme3.scene.Geometry

    associateWithGroupNode, breadthFirstTraversal, checkCulling, clone, computeWorldMatrix, deepClone, depthFirstTraversal, getFallbackMorphTarget, getLodLevel, getMaterial, getMesh, getModelBound, getMorphState, getMorphState, getNbSimultaneousGPUMorph, getTriangleCount, getVertexCount, getWorldMatrix, isBatched, isDirtyMorph, isGrouped, isIgnoreTransform, oldDeepClone, removeFromParent, setDirtyMorph, setFallbackMorphTarget, setIgnoreTransform, setLodLevel, setMaterial, setMesh, setModelBound, setMorphState, setMorphState, setNbSimultaneousGPUMorph, setParent, unassociateFromGroupNode, updateModelBound, updateWorldBound, updateWorldLightList, updateWorldTransforms

    Methods inherited from class com.jme3.scene.Spatial

    addControl, addControlAt, addLight, addMatParamOverride, breadthFirstTraversal, center, clearMatParamOverrides, depthFirstTraversal, forceRefresh, getBatchHint, getControl, getControl, getCullHint, getKey, getLastFrustumIntersection, getLocalBatchHint, getLocalCullHint, getLocalLightList, getLocalMatParamOverrides, getLocalQueueBucket, getLocalRotation, getLocalScale, getLocalShadowMode, getLocalToWorldMatrix, getLocalTransform, getLocalTranslation, getName, getNumControls, getParent, getQueueBucket, getShadowMode, getUserData, getUserDataKeys, getWorldBound, getWorldLightList, getWorldMatParamOverrides, getWorldRotation, getWorldScale, getWorldTransform, getWorldTranslation, hasAncestor, jmeClone, localToWorld, lookAt, matches, move, move, oldClone, removeControl, removeControl, removeLight, removeMatParamOverride, rotate, rotate, rotateUpTo, runControlRender, scale, scale, setBatchHint, setBoundRefresh, setCullHint, setKey, setLastFrustumIntersection, setLightListRefresh, setLocalRotation, setLocalRotation, setLocalScale, setLocalScale, setLocalScale, setLocalTransform, setLocalTranslation, setLocalTranslation, setMatParamOverrideRefresh, setName, setQueueBucket, setRequiresUpdates, setShadowMode, setTransformRefresh, setUserData, toString, updateGeometricState, updateLogicalState, updateMatParamOverrides, worldToLocal

    Methods inherited from class java.lang.Object

    equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

  • Field Details

    • geomap

      protected LODGeomap geomap

    • lod

      protected int lod

    • previousLod

      protected int previousLod

    • lodLeft

      protected int lodLeft

    • lodTop

      protected int lodTop

    • lodRight

      protected int lodRight

    • lodBottom

      protected int lodBottom

    • size

      protected int size

    • totalSize

      protected int totalSize

    • quadrant

      protected short quadrant

    • stepScale

      protected com.jme3.math.Vector3f stepScale

    • offset

      protected com.jme3.math.Vector2f offset

    • offsetAmount

      protected float offsetAmount

    • leftNeighbour

      protected TerrainPatch leftNeighbour

    • topNeighbour

      protected TerrainPatch topNeighbour

    • rightNeighbour

      protected TerrainPatch rightNeighbour

    • bottomNeighbour

      protected TerrainPatch bottomNeighbour

    • searchedForNeighboursAlready

      protected boolean searchedForNeighboursAlready

    • worldTranslationCached

      protected com.jme3.math.Vector3f worldTranslationCached

    • worldScaleCached

      protected com.jme3.math.Vector3f worldScaleCached

    • lodEntropy

      protected float[] lodEntropy

  • Constructor Details

    • TerrainPatch

      public TerrainPatch()

    • TerrainPatch

      public TerrainPatch(String name)

    • TerrainPatch

      public TerrainPatch(String name, int size)

    • TerrainPatch

      public TerrainPatch(String name, int size, com.jme3.math.Vector3f stepScale, float[] heightMap, com.jme3.math.Vector3f origin)
      Constructor instantiates a new TerrainPatch object. The parameters and heightmap data are then processed to generate a TriMesh object for rendering.
      Parameters:
      name - the name of the terrain patch.
      size - the size of the heightmap.
      stepScale - the scale for the axes.
      heightMap - the height data.
      origin - the origin offset of the patch.

    • TerrainPatch

      public TerrainPatch(String name, int size, com.jme3.math.Vector3f stepScale, float[] heightMap, com.jme3.math.Vector3f origin, int totalSize, com.jme3.math.Vector2f offset, float offsetAmount)
      Constructor instantiates a new TerrainPatch object. The parameters and heightmap data are then processed to generate a TriMesh object for rendering.
      Parameters:
      name - the name of the terrain patch.
      size - the size of the patch.
      stepScale - the scale for the axes.
      heightMap - the height data.
      origin - the origin offset of the patch.
      totalSize - the total size of the terrain. (Higher if the patch is part of a TerrainQuad tree.)
      offset - the offset for texture coordinates.
      offsetAmount - the total offset amount. Used for texture coordinates.

  • Method Details

    • generateLodEntropies

      public void generateLodEntropies()
      This calculation is slow, so don't use it often.

    • getLodEntropies

      public float[] getLodEntropies()

    • getHeightMap

      public float[] getHeightMap()

    • getMaxLod

      public int getMaxLod()
      The maximum lod supported by this terrain patch. If the patch size is 32 then the returned value would be log2(32)-2 = 3 You can then use that value, 3, to see how many times you can divide 32 by 2 before the terrain gets too un-detailed (can't stitch it any further).
      Returns:
      the maximum LOD

    • reIndexGeometry

      protected void reIndexGeometry(HashMap<String,UpdatedTerrainPatch> updated, boolean useVariableLod)

    • getTex

      public com.jme3.math.Vector2f getTex(float x, float z, com.jme3.math.Vector2f store)

    • getHeightmapHeight

      public float getHeightmapHeight(float x, float z)

    • getTriangle

      public com.jme3.math.Triangle getTriangle(float x, float z)
      Get the triangle of this geometry at the specified local coordinate.
      Parameters:
      x - local to the terrain patch
      z - local to the terrain patch
      Returns:
      the triangle in world coordinates, or null if the point does intersect this patch on the XZ axis

    • getGridTriangles

      public com.jme3.math.Triangle[] getGridTriangles(float x, float z)
      Get the triangles at the specified grid point. Probably only 2 triangles
      Parameters:
      x - local to the terrain patch
      z - local to the terrain patch
      Returns:
      the triangles in world coordinates, or null if the point does intersect this patch on the XZ axis

    • setHeight

      protected void setHeight(List<TerrainQuad.LocationHeight> locationHeights, boolean overrideHeight)

    • updateNormals

      protected void updateNormals()
      Recalculates all normal vectors in this terrain patch.

    • fixNormalEdges

      protected void fixNormalEdges(TerrainPatch right, TerrainPatch bottom, TerrainPatch top, TerrainPatch left, TerrainPatch bottomRight, TerrainPatch bottomLeft, TerrainPatch topRight, TerrainPatch topLeft)
      Matches the normals along the edge of the patch with the neighbours. Computes the normals for the right, bottom, left, and top edges of the patch, and saves those normals in the neighbour's edges too. Takes 4 points (if it has a neighbour on that side) for each point on the edge of the patch: * | *---x---* | * It works across the right side of the patch, from the top down to the bottom. Then it works on the bottom side of the patch, from the left to the right.

    • averageNormalsTangents

      protected void averageNormalsTangents(com.jme3.math.Vector3f topPoint, com.jme3.math.Vector3f rootPoint, com.jme3.math.Vector3f leftPoint, com.jme3.math.Vector3f bottomPoint, com.jme3.math.Vector3f rightPoint, com.jme3.math.Vector3f normal, com.jme3.math.Vector3f tangent, com.jme3.math.Vector3f binormal)

    • getMeshNormal

      protected com.jme3.math.Vector3f getMeshNormal(int x, int z)

    • getHeight

      protected float getHeight(int x, int z, float xm, float zm)

    • lockMesh

      public void lockMesh()
      Locks the mesh (sets it static) to improve performance. If it is not editable, then unlock to make it editable.

    • unlockMesh

      public void unlockMesh()
      Unlocks the mesh (sets it dynamic) to make it editable. It will be editable but performance will be reduced. Call lockMesh to improve performance.

    • getOffsetAmount

      public float getOffsetAmount()
      Returns the offset amount this terrain patch uses for textures.
      Returns:
      The current offset amount.

    • getStepScale

      public com.jme3.math.Vector3f getStepScale()
      Returns the step scale that stretches the height map.
      Returns:
      The current step scale.

    • getTotalSize

      public int getTotalSize()
      Returns the total size of the terrain.
      Returns:
      The terrain's total size.

    • getSize

      public int getSize()
      Returns the size of this terrain patch.
      Returns:
      The current patch size.

    • getOffset

      public com.jme3.math.Vector2f getOffset()
      Returns the current offset amount. This is used when building texture coordinates.
      Returns:
      The current offset amount.

    • setOffset

      public void setOffset(com.jme3.math.Vector2f offset)
      Sets the value for the current offset amount to use when building texture coordinates. Note that this does NOT rebuild the terrain at all. This is mostly used for outside constructors of terrain patches.
      Parameters:
      offset - The new texture offset.

    • setSize

      public void setSize(int size)
      Sets the size of this terrain patch. Note that this does NOT rebuild the terrain at all. This is mostly used for outside constructors of terrain patches.
      Parameters:
      size - The new size.

    • setTotalSize

      public void setTotalSize(int totalSize)
      Sets the total size of the terrain . Note that this does NOT rebuild the terrain at all. This is mostly used for outside constructors of terrain patches.
      Parameters:
      totalSize - The new total size.

    • setStepScale

      public void setStepScale(com.jme3.math.Vector3f stepScale)
      Sets the step scale of this terrain patch's height map. Note that this does NOT rebuild the terrain at all. This is mostly used for outside constructors of terrain patches.
      Parameters:
      stepScale - The new step scale.

    • setOffsetAmount

      public void setOffsetAmount(float offsetAmount)
      Sets the offset of this terrain texture map. Note that this does NOT rebuild the terrain at all. This is mostly used for outside constructors of terrain patches.
      Parameters:
      offsetAmount - The new texture offset.

    • getQuadrant

      public short getQuadrant()
      Returns:
      Returns the quadrant.

    • setQuadrant

      public void setQuadrant(short quadrant)
      Parameters:
      quadrant - The quadrant to set.

    • getLod

      public int getLod()

    • setLod

      public void setLod(int lod)

    • getPreviousLod

      public int getPreviousLod()

    • setPreviousLod

      public void setPreviousLod(int previousLod)

    • getLodLeft

      protected int getLodLeft()

    • setLodLeft

      protected void setLodLeft(int lodLeft)

    • getLodTop

      protected int getLodTop()

    • setLodTop

      protected void setLodTop(int lodTop)

    • getLodRight

      protected int getLodRight()

    • setLodRight

      protected void setLodRight(int lodRight)

    • getLodBottom

      protected int getLodBottom()

    • setLodBottom

      protected void setLodBottom(int lodBottom)

    • collideWith

      public int collideWith(com.jme3.collision.Collidable other, com.jme3.collision.CollisionResults results) throws com.jme3.collision.UnsupportedCollisionException
      Specified by:
      collideWith in interface com.jme3.collision.Collidable
      Overrides:
      collideWith in class com.jme3.scene.Geometry
      Throws:
      com.jme3.collision.UnsupportedCollisionException

    • worldCoordinateToLocal

      protected com.jme3.math.Vector3f worldCoordinateToLocal(com.jme3.math.Vector3f loc)

    • write

      public void write(com.jme3.export.JmeExporter ex) throws IOException
      Specified by:
      write in interface com.jme3.export.Savable
      Overrides:
      write in class com.jme3.scene.Geometry
      Throws:
      IOException

    • read

      public void read(com.jme3.export.JmeImporter im) throws IOException
      Specified by:
      read in interface com.jme3.export.Savable
      Overrides:
      read in class com.jme3.scene.Geometry
      Throws:
      IOException

    • clone

      public TerrainPatch clone()
      Specified by:
      clone in interface com.jme3.asset.CloneableSmartAsset
      Overrides:
      clone in class com.jme3.scene.Geometry

    • cloneFields

      public void cloneFields(com.jme3.util.clone.Cloner cloner, Object original)
      Called internally by com.jme3.util.clone.Cloner. Do not call directly.
      Specified by:
      cloneFields in interface com.jme3.util.clone.JmeCloneable
      Overrides:
      cloneFields in class com.jme3.scene.Geometry

    • ensurePositiveVolumeBBox

      protected void ensurePositiveVolumeBBox()

    • cacheTerrainTransforms

      protected void cacheTerrainTransforms()
      Caches the transforms (except rotation) so the LOD calculator, which runs on a separate thread, can access them safely.

    • getWorldScaleCached

      public com.jme3.math.Vector3f getWorldScaleCached()

    • getWorldTranslationCached

      public com.jme3.math.Vector3f getWorldTranslationCached()

    • clearCaches

      protected void clearCaches()
      Removes any references when the terrain is being removed.