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Action:
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Enables and disables polygonoffset 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:polygonoffset [on-off] [view=active])
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Arg Types:
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on-off
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boolean
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view
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view
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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) polygon offsetting. The polygons refer to those used in faceting a model, which is a requirement for rendering. When enabled and when model edges (view:edges) enabled, this command pushes the faceted polygon edges back so the model edges become more visible. Prevents z-buffer problems when displaying edges on top of the shaded object.
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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.
view:edges should be enabled to see any effect.
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Example:
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; view:polygonoffset
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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 cylinder1
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(solid:cylinder (position -10 -10 -10)
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(position -10 -10 30) 5))
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;; cylinder1
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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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; 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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; If edges are not turned on, you won't see
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; anything when shading is turned off.
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