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Define-geometry

The DEFINE-GEOMETRY menu or command lets the user access those options necessary to define the shape of the model using points, lines, surfaces, and solids.

This documentation is taken directly from the Moviestar help files and included here in a hyper-text format for your convenience.

More information available:

• Coordinate-frame
• Digitizer
• Line
• Point
• Solid
• Surface

Coordinate-frame

Define a local coordinate axis system. A coordinate system may be defined with respect to any other previously defined coordinate frame.

Cartesian

Define a local cartesian coordinate axis system.

Cylindrical

Define a local cylindrical coordinate axis system.

Delete

Delete a previously defined coordinate frame. Although the coordinate frame is no longer defined, all points defined in this system are not deleted but are now only available in the world coordinate system.

Rotate

Rotate a previously defined coordinate frame to define a new one.

Spherical

Define a local spherical coordinate axis system.

Translate

Translate a previously defined coordinate frame to define a new one.

Digitizer

Select and set parameters associated with the graphical input to data.

Detect

Enable or disable to digitizer as the primary source of geometric entity identification. While enabled, commands that require a previously defined point, line, surface, or solid as part of the command input will expect that input from either the graphics tablet or thumb wheels on device that support these input devices.

Orientation

Orients the tablet to the world coordinate axis. You must select a point on the digitizer and the enter the x, y, z coordinates of this point in the current coordinate frame. The three points entered define the transformation matrix.

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Line

Define lines using various formats.

Arc

Define a line by selecting beginning, mid, and end points.

Break

Break a line in two pieces by selecting a point on or near the line.

Conic

Define a line by selecting four points on the line. A cubic curve is fit so that it passes through these points.

Delete

Delete a previously defined line.

Enter

Define a line by entering its two end points.

Equation

Define a line by supplying its parametric coefficients. The parametric equations for the line are as follows:

     x(t) = a1*t**3 + a2*t**2 + a3*t + a4
     y(t) = b1*t**3 + b2*t**2 + b3*t + b4
     z(t) = c1*t**3 + c2*t**2 + c3*t + c4

Least squares

Define a line as the best least squares fit to the points selected.

Merge

Define a complex line as the concatenation of several other lines.

Mirror

Define a line as the mirror image of a previously defined line.

Reverse

Reverse the parametric direction of a line. Opposite sides of a surface must be defined with the same parametric direction. This command will produce a new line with the reversed parametric direction.

Rotate

Define a line by rotating a previously defined line about one of the local axes.

Scale

Define a line by scaling a previously defined line.

Smooth

Smooth several lines by forcing their end to be tangent.

Spline

Define a line by fitting a cubic spline to a list of points.

Sweep

Define a line by rotating a point about an arbitrarily defined axis. This generates an arc in three-space.

Translate

Define a line by translating a previously defined line to a new position.

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Point

Define points in space using various techniques.

Delete

Delete a point from the data base.

Enter

Define a new point to the data base by entering its coordinate triplet.

Line-interpolate

Define one or more points by interpolating along a previously defined line.

Mirror

Define a new point as the mirror image of a previously defined point.

On-line

Define a point on a previously defined line by entering the coordinates of a point near the line.

On-surface

Define a point on a previously defined surface by entering the coordinates of a point new the surface.

Point-interpolate

Define one or more points by interpolating along a line between the two end points chosen.

Rotate

Define a point by rotating a previously defined point about the current coordinate frame.

Scale

Define a point by scaling a previously defined point.

Solid-interpolate

Define one or more points by interpolating along the I, J, and K parametric directions through a solid.

Surface-interpolate

Define one or more points by interpolation along the I and J parametric directions through a surface.

Translate

Define a point by translating a previously defined point.

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Solid

Define a geometric solid, a logical hexahedron.

Delete

Delete a previously defined solid.

Enter

Define a solid by its eight corner points.

Equation

Define a solid by its parametric surface equations.

Lines

Define a solid by its twelve bounding lines.

Mirror

Define a solid as the mirror image of a previously defined solid.

Parametric

Define a solid by four surfaces in the same parametric direction.

Reverse

Reverse the direction of a solid.

Rotate

Define a solid by rotating a previously defined solid about the current coordinate frame.

Scale

Define a solid by scaling a previously defined solid.

Smooth

Smooth several solids by forcing their faces to be tangent.

Surfaces

Define a solid by its six bounding surfaces.

Sweep

Define a solid by rotating a surface about an arbitrary axis.

Translate

Define a solid by translating a previously defined solid.

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Surface

Define a geometric surface, a logical quadrilateral.

Break

Define two new surfaces by breaking a previously defined surface along a line joint points on opposite sides of the original surface.

Delete

Delete a previously defined surface.

Enter

Define a surface by its four corner points.

Equation

Define a surface by its parametric equation.

Lines

Define a surface by its four bounding lines.

Mirror

Define a surface as the mirror image of a previously defined surface.

Parametric

Define a surface by four lines in the same parametric direction.

Reverse

Reverse the direction of a parametric surface.

Rotate

Define a surface by rotating a previously defined surface about the current coordinate axis.

Scale

Define a surface by scaling a previously defined surface.

Smooth

Smooth several surfaces by forcing their common boundaries to be tangent.

Sweep

Define a surface by rotating a line about an arbitrarily defined axis.

Translate

Define a surface by translating a surface.

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On-line documentation

Jason K. ________________________________________________________________________________ Note: This documentation is being developed currently. Information is subject to change and is on a use at your own risk basis.

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