10/27/20151 UDK Terrain CIS 488/588 Bruce R. Maxim UM-Dearborn

10/27/20152 What is Terrain? Terrain is a tessellated piece of geometry used to model outdoor areas The geometry’s shape is driven by a height map (the z-axis defined by an 8-bit or 16-bit gray scale image) –Dark shades used to define valleys –Brighter shades are used to so peaks

10/27/20153 Height Map Used to define elevation and contours Use must use G16 pixel shading format, if you plan to use Unreal’s Terrain editing dialog Determines terrain’s physical dimensions: ResolutionX * TerrainScaleX – TerrainScaleX ResolutionY * TerrainScaleY – TerrainScaleY The default scale is 64 units in all axes

10/27/20154 Layers Controls the visual aspects of the terrain TerrainInfo actors can have 32 layers stacked on top of one another Each layer has two texture maps a color map and an alpha map (controls transparency and blending)

10/27/20155 DecoLayers Decoration layer textures are used to drive the placement of decoration objects (grass blades, trees, shrubs, etc.) Three types of texture maps associated with each Decolayer (density map, color map, scale map)

10/27/20156 Terrain In UDK you start from tools select New Terrain The you make adjustments with the terrain editor from the left hand tool pallet You can also right click and select properties for the terrain actor and make some adjustments there

10/27/20157 Terrain Editing Dialog Functions Creation and manipulation of height maps Assignment and blending of texture layers Assignment and manipulation of DecoLayers Automatic terrain generation

10/27/20158 Skybox In UDK a skybox is a static mesh with a sky material applied (can be cylinders or spheres as well as cubes) Use to provide the illusion of clouds, suns, moons, etc. far off in the distance Great for creating cloudy skies, night scenes, and futuristic space scenes

10/27/20159 Skybox Principles Select a sky static mesh from the content browser Position it in world using the view windows Make some property adjustments to get realistic lighting and shadows The trick is to avoid creation of seams in the sky box You can use fog to hide things