Basic Examples (3) 

A unit radius and two units height 3D annulus:

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A 3D annulus from the origin to {1,-1,1} with inner radius 1/2:

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Differently styled annuli:

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Scope (10) 

Specification (5) 

Specify radii:

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Specify centers:

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Annuli with different directions:

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Specify position, direction, as well as inner and outer radii:

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Short form for a 3D annulus centered at the origin with a radius 1:

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Styling (5) 

Color directives specify the face color of each annulus:

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FaceForm can be used to specify the styles of the interiors as well as exteriors:

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Different properties can be specified for the front and back faces using FaceForm:

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Opacity specifies the face opacity:

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Decompose the annulus into its components and apply different styling to each:

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Options (2) 

RoundingRadius (2) 

Adjust how rounded the edges are:

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Adjust the inner and outer edges independently:

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Applications (2) 

Create a model of a wheel:

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Use it to create a model of a chassis:

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Properties and Relations (4) 

RoundedAnnulus3D is a 3D generalization of Annulus in 2D:

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The resource function RoundedCylinder effectively corresponds to RoundedAnnulus3D with zero inner radius:

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PieChart3D or SectorChart3D can be used to create 3D rounded annuli:

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Get the graphical primitive from PieChart3D:

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Compare with RoundedAnnulus3D:

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Despite being seemingly the same, the two annuli have a very different internal structure:

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Possible Issues (5) 

When the two endpoints coincide, no annulus is created:

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Radii are assumed to be non-negative real numbers:

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When the inner radius exceeds the outer one, a warning is issued and artifacts appear:

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When rounding radii exceed the height of the annulus, a warning is issued and artifacts appear:

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When the sum of rounding radii exceeds the thickness of the annulus, a warning is issued and artifacts appear:

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Neat Examples (4) 

Random unit annuli:

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Concentric annuli:

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Use the degenerate radius specification to create a spool-like object:

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Create a model of a Roman amphitheater:

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