UE3:Terrain (UDK)

Object >> Actor >> Info >> Terrain

Package: 

Engine

Properties

Property group 'Collision'

bAllowRigidBodyUnderneath

Type: bool

Modifiers: const

If true, this allows rigid bodies to go underneath visible areas of the terrain. This adds some physics cost.

bBlockRigidBody

Type: bool

Modifiers: const

If false, primitive does not block rigid body physics.

Property is propagated to terrain components.

Default value: True

CollisionTesselationLevel

Type: int

The tessellation level to utilize when performing collision checks with non-zero extents.

Default value: 1

Property group 'Lighting'

bAcceptsDynamicLights

Type: bool

Modifiers: const

If false, primitive does not accept dynamic lights, aka lights with HasStaticShadowing() == FALSE

Property is propagated to terrain components.

Default value: True

bBilinearFilterLightmapGeneration

Type: bool

If true, the lightmap generation will be performed using the bilinear filtering that all other lightmap generation in the engine uses.

Default value: True

bCastDynamicShadow

Type: bool

Modifiers: const

If false, primitive does not cast dynamic shadows.

Property is propagated to terrain components .

Default value: True

bCastShadow

Type: bool

Whether terrain should cast shadows.

Property is propagated to terrain components

Default value: True

bEnableSpecular

Type: bool

If TRUE, enable specular on this terrain.

bForceDirectLightMap

Type: bool

Modifiers: const

If true, forces all static lights to use light-maps for direct lighting on the terrain, regardless of the light's UseDirectLightMap property.

Property is propagated to terrain components .

Default value: True

bIsOverridingLightResolution

Type: bool

If true, the light/shadow map size is no longer restricted... The size of the light map will be (per component): INT LightMapSizeX = Component->SectionSizeX * StaticLightingResolution + 1; INT LightMapSizeY = Component->SectionSizeY * StaticLightingResolution + 1;

So, the maximum size of a light/shadow map for a component will be: MaxMapSizeX = MaxComponentSize * StaticLightingResolution + 1 MaxMapSizeY = MaxComponentSize * StaticLightingResolution + 1

Be careful with the setting of StaticLightingResolution when this mode is enabled. It will be quite easy to run up a massive texture requirement on terrain!

LightingChannels

Type: LightComponent.LightingChannelContainer

Modifiers: const

Lighting channels controlling light/ primitive interaction. Only allows interaction if at least one channel is shared

Default value:

Member	Value
bInitialized	True
Static	True

StaticLightingResolution

Type: int

The resolution to cache lighting at, in texels/patch. A separate shadow-map is used for each terrain component, which is up to (MaxComponentSize * StaticLightingResolution + 1) pixels on a side. Must be a power of two, 1 <= StaticLightingResolution <= MaxTesselationLevel.

Default value: 4

Property group 'Lightmass'

LightmassSettings

Type: EngineTypes.LightmassPrimitiveSettings

Lightmass settings for the terrain

Default value:

Member	Value
DiffuseBoost	1.0
EmissiveBoost	1.0
EmissiveLightFalloffExponent	2.0
FullyOccludedSamplesFraction	1.0
SpecularBoost	1.0

Property group 'Physics'

TerrainPhysMaterialOverride

Type: PhysicalMaterial

Modifiers: const

PhysicalMaterial to use for entire terrain

Property group 'Terrain'

bMorphingEnabled

Type: bool

Whether to utilize morping terrain or not

bMorphingGradientsEnabled

Type: bool

Whether to utilize morping gradients or not (bMorphingEnabled must be true for this to matter)

bShowWireframe

Type: bool

Tells the terrain to render in wireframe.

DecoLayers

Type: array<TerrainDecoLayer>

Modifiers: const

Array of the decoration layers applied

EditorTessellationLevel

Type: int

Modifiers: transient

Editor-viewing tessellation level

Layers

Type: array<TerrainLayer>

Modifiers: const

Array of the terrain layers applied to the terrain

MaxComponentSize

Type: int

For rendering and collision, split the terrain into components with a maximum size of (MaxComponentSize,MaxComponentSize) patches. The terrain is split up into rectangular groups of patches called terrain components for rendering. MaxComponentSize is the maximum number of patches in a single row/column of a terrain component. Generally, all components will be MaxComponentSize patches square, but on terrains with a patch resolution which isn't a multiple of MaxComponentSize, there will be some components along the edges which are smaller.

This is limited by the MaxTesselationLevel, to prevent the vertex buffer for a fully tessellated component from being > 65536 vertices. For a MaxTesselationLevel of 16, MaxComponentSize is limited to <= 15. For a MaxTesselationLevel of 8, MaxComponentSize is limited to <= 31.

PostEditChange clamps this to be >= 1.

Default value: 16

MaxTesselationLevel

Type: int

The maximum number of quads in a single row/column of a tessellated patch.

Must be a power of two, 1 <= MaxTesselationLevel <= 16

Default value: 4

MinTessellationLevel

Type: int

The minimum number of quads in a tessellated patch. Must be a power of two, 1 <= MaxTesselationLevel

Default value: 1

NormalMapLayer

Type: int

The index of the layer that supplies the normal map for the whole terrain. If this is -1, the terrain will compile the normal property the old way (all normal maps blended together). If this is a valid index into the layer array, it will compile the normal property only for the material(s) contained in said layer.

Default value: -1

NumPatchesX

Type: int

The number of patches in a single row of the terrain's patch grid.

PostEditChange clamps this to be >= 1.

Note that if you make this and/or NumPatchesY smaller, it will destroy the height-map/alpha-map data which is no longer used by the patches.If you make the dimensions larger, it simply fills in the new height-map/alpha-map data with zero.

Default value: 1

NumPatchesY

Type: int

The number of patches in a single column of the terrain's patch grid.

PostEditChange clamps this to be >= 1.

Default value: 1

TesselationDistanceScale

Type: float

The scale factor to apply to the distance used in determining the tessellation level to utilize when rendering a patch. TessellationLevel = SomeFunction((Patch distance to camera) * TesselationDistanceScale)

Default value: 1.0

TessellationCheckDistance

Type: float

The radius from the view origin that terrain tessellation checks should be performed. If less than 0, the general setting from the engine configuration will be used. If 0.0, every component will be checked for tessellation changes each frame.

Default value: -1.0

WireframeColor

Type: Object.Color

The color to use when rendering the wireframe of the terrain.

Default value:

Member	Value
A	0
B	255
G	255
R	0

Internal variables

AlphaMaps

Type: array<AlphaMap>

Modifiers: native, const

Array of the alpha maps between layers

bHeightmapLocked

Type: bool

The terrain heightmap is locked - no editing can take place on it

bLocked

Type: bool

The terrain is locked - no editing can take place on it

bShowingCollision

Type: bool

Viewing collision tessellation level

CachedDisplacements

Type: array<byte>

Modifiers: native, const

INTERNAL - Displacement related values

CachedTerrainMaterials

Type: CachedTerrainMaterialArray

Array size: 2

Modifiers: native, const

array of cached terrain materials for SM2,SM3

Heights

Type: array<TerrainHeight>

Modifiers: private, const, native

Array of the terrain heights

InfoData

Type: array<TerrainInfoData>

Modifiers: private, const, native

Array of the terrain information data (visible, etc.)

LightingGuid

Type: Object.Guid

Modifiers: private, const

Unique ID for this terrain, used for caching during distributed lighting

MaxCollisionDisplacement

Type: float

Modifiers: native, const

NumSectionsX

Type: int

Modifiers: const

Internal values used to setup components

The number of sections is the number of terrain components along the X and Y of the 'grid'.

NumSectionsY

Type: int

Modifiers: const

NumVerticesX

Type: int

Modifiers: const

The number of vertices currently stored in a single row of height and alpha data. Updated from NumPatchesX when Allocate is called(usually from PostEditChange).

NumVerticesY

Type: int

Modifiers: const

The number of vertices currently stored in a single column of height and alpha data. Updated from NumPatchesY when Allocate is called(usually from PostEditChange).

ReleaseResourcesFence

Type: pointer{FRenderCommandFence}

Modifiers: native, const

Command fence used to shut down properly

SectionSize

Type: int

Modifiers: const

Legacy!

SelectedVertices

Type: array<SelectedTerrainVertex>

Modifiers: transient

TerrainComponents

Type: array<TerrainComponent>

Modifiers: const, nontransactional

The array of terrain components that are used by the terrain

WeightedMaterials

Type: array<TerrainWeightedMaterial>

Modifiers: private, native, const

INTERNAL - The weighted materials and blend maps

WeightedTextureMaps

Type: array<TerrainWeightMapTexture>

Modifiers: private, const, native

Default values

Property	Value
bBlockActors	True
bCollideActors	True
bEdShouldSnap	True
bHidden	False
bNoDelete	True
bStatic	True
bWorldGeometry	True
CollisionType	COLLIDE_CustomDefault
DrawScale3D	Member Value X 256.0 Y 256.0 Z 256.0

Subobjects

Sprite

Class: Engine.SpriteComponent

Inherits from: Info.Sprite

Property	Value
ReplacementPrimitive	None
Sprite	Texture2D'EditorResources.S_Terrain'

Structs

AlphaMap

A mapping used to apply a layer to the terrain. Full structure can be found in UnTerrain.h, FAlphaMap.

(No member variables.)

CachedTerrainMaterialArray

Modifiers: native

array<pointer{FTerrainMaterialResource}> CachedMaterials 

No UObject references.

SelectedTerrainVertex

Selected vertex structure - used for vertex editing

int X 

The position of the vertex.

int Y 

The position of the vertex.

int Weight 

The weight of the selection.

TerrainDecoLayer

A decoration layer - used to easily apply static meshes to the terrain

string Name 

The name of the DecoLayer, for UI display purposes.

array<TerrainDecoration> Decorations 

The decoration(s) to apply for this layer.

int AlphaMapIndex 

INTERNAL: The index of the alpha map that represents the application of this layer.

Default values:

Property	Value
AlphaMapIndex	-1

TerrainDecoration

A decoration source for terrain DecoLayers.

PrimitiveComponentFactory Factory 

The factory used to generate the decoration mesh.

float MinScale 

The min scale to apply to the source mesh.

float MaxScale 

The max scale to apply to the source mesh.

float Density 

The density to use when applying the mesh to the terrain.

float SlopeRotationBlend 

The amount to rotate the mesh to match the slope of the terrain

where it is being placed. If 1.0, the mesh will match the slope exactly.

int RandSeed 

The value to use to seed the random number generator.

array<TerrainDecorationInstance> Instances 

INTERNAL: An array of instances of the decoration applied to the

terrain.

Default values:

Property	Value
Density	0.01
MaxScale	1.0
MinScale	1.0

TerrainDecorationInstance

A decoration instance applied to the terrain. Used internally to apply DecoLayers.

PrimitiveComponent Component 

No UObject references.

float X 

float Y 

float Scale 

int Yaw 

TerrainHeight

A height data entry that is stored in an array for the terrain. Full structure can be found in UnTerrain.h, FTerrainHeight.

(No member variables.)

TerrainInfoData

InfoData entries for each patch in the terrain. This includes information such as whether the patch is visible or not (holes). Full structure can be found in UnTerrain.h, FTerrainInfoData.

(No member variables.)

TerrainLayer

A layer that can be painted onto the terrain.

string Name 

The name of the layer, for UI display purposes.

TerrainLayerSetup Setup 

The TerrainLayerSetup, which declares the material(s) used in the layer.

int AlphaMapIndex 

INTERNAL: The index of the alpha map that represents the application of this layer.

bool Highlighted 

Whether the layer should be highlighted when rendered.

bool WireframeHighlighted 

Whether the layer should be wireframe highlighted when rendered.

CURRENTLY NOT IMPLEMENTED

bool Hidden 

Whether the layer is hidden (not rendered).

Object.Color HighlightColor 

The color to highlight the layer with.

Object.Color WireframeColor 

The color to wireframe highlight the layer with.

int MinX 

Rectangle encompassing all the vertices this layer affects.

TerrainLayerSetup::SetMaterial() uses this to avoid rebuilding terrain that has not changed

int MinY 

Rectangle encompassing all the vertices this layer affects.

TerrainLayerSetup::SetMaterial() uses this to avoid rebuilding terrain that has not changed

int MaxX 

Rectangle encompassing all the vertices this layer affects.

TerrainLayerSetup::SetMaterial() uses this to avoid rebuilding terrain that has not changed

int MaxY 

Rectangle encompassing all the vertices this layer affects.

TerrainLayerSetup::SetMaterial() uses this to avoid rebuilding terrain that has not changed

Default values:

Property	Value
AlphaMapIndex	-1
HighlightColor	Member Value B 255 G 255 R 255

TerrainMaterialResource

Terrain material resource - compiled terrain material used to render the terrain. Full structure can be found in UnTerrain.h, FTerrainMaterialResource.

(No member variables.)

TerrainWeightedMaterial

A weighted material used on the terrain. Full structure can be found in UnTerrain.h, FTerrainWeightedMaterial.

(No member variables.)

Functions

Native functions

CalcLayerBounds

native final function CalcLayerBounds ()

for each layer, calculate the rectangle encompassing all the vertices affected by it and store the result in the layer's MinX, MinY, MaxX, and MaxY properties

Events

PostBeginPlay

simulated event PostBeginPlay ()

Overrides: Actor.PostBeginPlay