2009

how much light is reflected by the surface towards the viewer. Shaders of this class may be thought of
as defining a surface's "finish", and are used to model properties such as matte, metal and plastic.
• Small surface perturbations can be supported by means of displacement shaders. Typically, a
displacement shader will give an otherwise smooth surface an irregular or indented appearance.
Displacement shaders are used to represent features that would be difficult, impossible, or inefficient if
conventional modelling techniques were used. For example, rough metal castings and the regular
indentations produced by pressed sheet metal can be simulated.
Normally the material editor displays a selection of the most important parameters from all shaders within
the material tab. If the user profile (see "Profiles" under "Interface" in the Basic NavisWorks Functionality
section for more information on this) is set to Developer, then all four shaders can be edited and changed
individually.
Some shaders are described as "wrapped". These define a flat, two dimensional material, like wall paper.
Wrapped materials need a texture space shader to define how they should be applied to (wrapped
around) a three dimensional object. Materials that include a wrapped shader can also include a texture
space shader. A special type of texture space shader, called a layout shader, can be used to transform
(rotate, stretch, offset) the two dimensional material before it is applied to the three dimensional object.
Transforms are based around an origin point, which by default, is the top left hand corner of the image
(refer to the diagram below, where the image is enscribed in the red square, which is then repeated. The
default origin is Point 1). Checking the Offset Center check box will reposition the origin to the center of
the image (Point 2). Finally, in Developer profile, you can edit the Decal Mode, choosing from either
Default or Normalized. Selecting Normalized will move the origin to the lower left corner of the image
(Point 3, with the Offset Center option un-checked). With both Normalized and Offset Center selected,
the origin will be repositioned in the center of the repeated image, directly below (Point 4).
Presenter Materials
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