Texture Arrays for Height Mapped Surfaces
Texture array feature allows
many textures to be applied to a surface. Feature is intended for large
scale height mapped surfaces representing terrains. Setting
up a Texture Array Surface Create and select a height mapped
surface as Surface A. In Height Map tab of
Surface Effects dialog open Texture Options
dialog. Enable Use Texture Array and select
resolution. There will be no immediate differences in rendering of the surface
on enablement. Texture Array Features
Texture arrays contain a collection of textures all of the same
resolution and format. All textures will be scaled to the array resolution
when assigning textures on an array textured surface. Up to 63 textures
may be included in the array. Texture Array
Surface Characteristics Texture array surfaces are subdivided
into tiles. Each tile may contain a unique set of surface
characteristics. Following table lists characteristics that apply to
entire surface and per tile.
Selecting Surface Array Tiles Select
individual tiles by moving mouse pointer on an array surface and click middle
button. Tile will highlight to different color on the surface. Subsequent
middle click on highlighted tile will deselect. Status bar will indicate
a texture array surface and number of selected tiles.
Select a range of tiles by holding middle button down and dragging around
the surface. Deselect a range of tiles on a surface by holding middle
mouse button + Ctrl key down while dragging around the surface.
Deselect all tiles with a middle mouse button click + Ctrl key down or over
a another surface/empty area. Note: When selecting
tiles any instance objects should be deselected, interactive instance feature
will take precedence over tile selection showing instance brush instead of
tiles.Blending Textures Between Tiles
Seamlessly Array tiles are rectangular, seamless texture
blending throughout surface with various textures requires use of a Blend Factor Map assigned to texture array surface.
Use a Blend Factor Map and texture blending to transition or combine textures
seamlessly as shown in example. Note:
Height/Blend factor maps are created externally Array
Surface showing textured tiles without a blend factor map
Blend Factor Map with R/G channels designating texture blending. In
this case up to 3 textures can be combined per tile. A grey scale blend
factor map may combine 2 textures per tile.
Result of Texture Array Surface with Blend Factor Map applied.
Note: Texture wrap S/T is disabled for blend factor map to map across entire
Reflection Color with Texture Array Tiles Using specular
reflection on texture array surface requires using a specular map. Specular
map contains a scalar factor specifying which Texel's are light reflective.
Specular color set in the Surface Effects dialog modulates specular reflection
color & intensity for a tile. Specular map factor blends with the
associated color map (base, blend, blend 2 maps) based on blend factor map.
This allows 1 or more maps to show specular and transition seamlessly between
specular reflective regions. If there is no associated specular map with a
color map the specular factor defaults to 0 resulting in no specular color
reflection. Specular reflection requires factor sampled from the
specular map, specular color and power on the tile to be non-zero to show.
There is no constant specular reflection using only the specular color as set
from the Surface Effects dialog (although this effect can be achieved using
an all white specular map and assigning to a tile)
Visual 3D Modeler User's
Guide Rev 1.7