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Action:
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Enables and disables shading of faces within an
OpenGL view.
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Filename:
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gi/gi_scm/view_scm_gi.cxx
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Syntax:
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(view:shaded [on-off] [view=active])
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Arg Types:
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view
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view
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on-off
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boolean
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Returns:
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view
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Description:
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The
on-off argument enables (#t) and disables (#f) shading within a view. When disabled and model edges (view:edges) enabled, the result is similar to a wireframe representation only without the silhouette lines.
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Shading (view:shaded) and edge (view:edges) display must be enabled for doing "fake" hidden line (view:hiddenline).
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Displaying edges while shading of faces is turned off is not the same thing as a wire frame representation. An
ACIS wire frame representation shows silhouette lines, whereas displaying edges does not. The following figure shows the silhouette lines of a wire frame representation of a cylinder (on the left) and the edges of a cylinder with face shading turned off (on the right).
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Figure 3-4. Silhouette lines versus Edges
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Limitations:
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This extension is available on all platforms, but produces results only on NT using OpenGL. Works in
OpenGL views only. When shading is turned off,
view:edges should be enabled, otherwise nothing will be visible.
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Example:
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; view:shaded
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; Define a view.
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(define view1 (view:gl))
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;; #[view 1075519376]
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; Define a block.
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(define block1
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(solid:block (position 0 0 0)
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(position 25 20 30)))
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;; block1
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(define cyl1
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(solid:cylinder (position -10 -10 -10)
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(position -10 -10 30) 5))
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;; cyl1
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; Verify that edges are turned on
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(view:edges #t view1)
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;; #[view 1075519376]
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; If edges are not turned on, you won't see
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; anything when shading is turned off.
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; Turn shading off.
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(view:shaded #f view1)
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;; #[view 1075519376]
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; The edges of the model should be visible.
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; Note that silhouettes are not visible on the
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; cylinder.
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; Verify that shading is turned on
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(view:shaded #t view1)
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;; #[view 1075519376]
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; Turn on polygon offset to make edges easier to see
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(view:polygonoffset #t view1)
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;; #[view 1075519376]
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