// TODO: redo terrain implementation selection to allow other base types than heightMap.
private BSTerrainPhys BuildPhysicalTerrain(uint id, float[] heightMap)
{
// Find high and low points of passed heightmap.
// The min and max passed in is usually the area objects can be in (maximum
// object height, for instance). The terrain wants the bounding box for the
// terrain so replace passed min and max Z with the actual terrain min/max Z.
float minZ = float.MaxValue;
float maxZ = float.MinValue;
foreach (float height in heightMap)
{
if (height < minZ)
{
minZ = height;
}
if (height > maxZ)
{
maxZ = height;
}
}
if (minZ == maxZ)
{
// If min and max are the same, reduce min a little bit so a good bounding box is created.
minZ -= BSTerrainManager.HEIGHT_EQUAL_FUDGE;
}
Vector3 minCoords = new Vector3(0, 0, minZ);
Vector3 maxCoords = new Vector3(PhysicsScene.Scene.RegionInfo.RegionSizeX, PhysicsScene.Scene.RegionInfo.RegionSizeY, maxZ);
PhysicsScene.Logger.DebugFormat("{0} Terrain for {1}/ created with {2}",
LogHeader, PhysicsScene.RegionName,
(BSTerrainPhys.TerrainImplementation)BSParam.TerrainImplementation);
BSTerrainPhys newTerrainPhys = null;
switch ((int)BSParam.TerrainImplementation)
{
case (int)BSTerrainPhys.TerrainImplementation.Heightmap:
newTerrainPhys = new BSTerrainHeightmap(PhysicsScene, Vector3.Zero, id,
heightMap, minCoords, maxCoords);
break;
case (int)BSTerrainPhys.TerrainImplementation.Mesh:
newTerrainPhys = new BSTerrainMesh(PhysicsScene, Vector3.Zero, id,
heightMap, minCoords, maxCoords);
break;
default:
PhysicsScene.Logger.ErrorFormat("{0} Bad terrain implementation specified. Type={1}/{2},Region={3}",
LogHeader,
(int)BSParam.TerrainImplementation,
BSParam.TerrainImplementation,
PhysicsScene.RegionName);
break;
}
return(newTerrainPhys);
}
// Create the initial instance of terrain and the underlying ground plane.
// This is called from the initialization routine so we presume it is
// safe to call Bullet in real time. We hope no one is moving prims around yet.
public void CreateInitialGroundPlaneAndTerrain()
{
DetailLog("{0},BSTerrainManager.CreateInitialGroundPlaneAndTerrain,region={1}", BSScene.DetailLogZero, PhysicsScene.RegionName);
// The ground plane is here to catch things that are trying to drop to negative infinity
BulletShape groundPlaneShape = PhysicsScene.PE.CreateGroundPlaneShape(BSScene.GROUNDPLANE_ID, 1f, BSParam.TerrainCollisionMargin);
m_groundPlane = PhysicsScene.PE.CreateBodyWithDefaultMotionState(groundPlaneShape,
BSScene.GROUNDPLANE_ID, Vector3.Zero, Quaternion.Identity);
PhysicsScene.PE.AddObjectToWorld(PhysicsScene.World, m_groundPlane);
PhysicsScene.PE.UpdateSingleAabb(PhysicsScene.World, m_groundPlane);
// Ground plane does not move
PhysicsScene.PE.ForceActivationState(m_groundPlane, ActivationState.DISABLE_SIMULATION);
// Everything collides with the ground plane.
m_groundPlane.collisionType = CollisionType.Groundplane;
m_groundPlane.ApplyCollisionMask(PhysicsScene);
m_terrain = new BSTerrainHeightmap(PhysicsScene, Vector3.Zero, BSScene.TERRAIN_ID, m_worldMax);
}
// If called for terrain has has not been previously allocated, a new terrain will be built
// based on the passed information. The 'id' should be either the terrain id or
// BSScene.CHILDTERRAIN_ID. If the latter, a new child terrain ID will be allocated and used.
// The latter feature is for creating child terrains for mega-regions.
// If there is an existing terrain body, a new
// terrain shape is created and added to the body.
// This call is most often used to update the heightMap and parameters of the terrain.
// (The above does suggest that some simplification/refactoring is in order.)
// Called during taint-time.
private void UpdateTerrain(uint id, float[] heightMap)
{
DetailLog("{0},BSTerrainManager.UpdateTerrain,call,id={1}",
BSScene.DetailLogZero, id);
if (m_terrain != null)
{
// There is already a terrain in this spot. Free the old and build the new.
DetailLog("{0},BSTErrainManager.UpdateTerrain:UpdateExisting,call,id={1}",
BSScene.DetailLogZero, id);
// Release any physical memory it may be using.
m_terrain.Dispose();
m_terrain = BuildPhysicalTerrain(id, heightMap);
m_terrainModified = true;
}
else
{
// We don't know about this terrain so either we are creating a new terrain or
// our mega-prim child is giving us a new terrain to add to the phys world
// if this is a child terrain, calculate a unique terrain id
uint newTerrainID = id;
if (newTerrainID >= BSScene.CHILDTERRAIN_ID)
{
newTerrainID = ++m_terrainCount;
}
DetailLog("{0},BSTerrainManager.UpdateTerrain:NewTerrain,taint,newID={1}",
BSScene.DetailLogZero, newTerrainID);
m_terrain = BuildPhysicalTerrain(id, heightMap);
m_terrainModified = true;
}
}
