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Insectoids User Guide

The Insectoids user interface has :

Parameters that affect all stages [Global Parameters].
Parameters that affect a particular stage [Local Parameters].

The following tables describe these sections in detail:

Command Purpose
Input Import an OBJ file containing a Polyline created in Alias.  This Polyline determines the number of stages in Insectoids.
Output Choose the OBJ file name to save the random paths.
Reset Reset all parameter values to program defaults.   Also delete all active stages and provide a fresh stage.
Process Start a session that computes and saves the random paths in the OBJ file specified via the Output command.
Exit Exit Insectoids.


Global Path Parameter Description


Seed is the ID of a set of paths generated in a session.  Since the paths are all unique and random, if ever you wanted to generate them again, you need to specify their Seed value. The Seed value is very useful when you are satisfied with the paths in general but want to fine tune their parameters. 

In Insectoids, paths are generated in every session using the current seed value.  If you dont like the randomness on the paths, change this value.  When you have a set of paths that you want to visit later, note its Seed value. 

The default Seed value is 100. 

Number Number of paths to generate in a session.

The default Number of paths is 5

Path Type Determines whether the paths are saved as Polylines or B-Splines

The default Path Type is B-spline


Global Insect Parameter Description
Size Size of the insect from head to tail as measured in Alias.  See From Insect Size for more information.

The default insect Size is 1

Orientation The axis along which of the head and tail of the insect is present in Alias.  Insectoids generates a small extension (out-growth) at the start of the path along this axis.  This extension consumes four vertices of the path.  If Insectoids suggests 104 frames for the animation, the first four frames will be spent on the extension and insect will fly from frame 5 to frame 104.   Therefore when rendering, you should start at frame 5 and end at frame 104. 

The default Orientation is Z axis. 


Global Stage Parameter Description
Stages Contains all the available stages for this session.   You can select the stage you want to edit by choosing its number from the drop down list.  

By default, Stage 0 is available for editing.

Connect All Stages If true, only one set of paths is generated. These paths pass through all stages.  If false, a separate set is created for each stage.  For example, if the number of paths to be generated is 5 and there are 3 stages, a total of 15 paths will be output if Connect All Stages is false.

By default, Connect All Stages is true


Local Stage Parameter Description
Start Point (x1, y1, z1) Start Point of the path in this stage

The default Start Point is (0, 0, 0)

End Point (x2, y2, z2) End Point of the path in this stage

The default End Point is (16, 16, 16)

Locks Below X, Y and Z components of Start and End points you will find their locks.  If you lock a component, you prevent it from being randomly generated.  A locked component will take the value specified in its text box.

Insectoids randomly generates a component such that it lies on or between the current values specified in the component text boxes of Start and  End points.   For example, if you unlock the X component of Start point (that is, x1), and have the values 1 and 10 set in the X component text boxes of Start and End points, a randomly generated x1 will be equal to 1 or 10 or lie in between.

By default all the components of Start and End points are locked.  

Dont Jitter In Prevents randomness in a particular axis.  When you are animating non-flying insects like beetles or ants you set the Z component of their Start and End points to zero and prevent jitter in the Z axis.  

The default value is none.  Thus the path jitters in all axes.

The next section describes the parameters that affect the shape of the path.  To take advantage of these parameters, you need to understand how Insectoids generates a random path.  A random path connects two points -- a start point (A) and an end point (B).  To generate this path, Insectoids first finds the midpoint (M) of the line joining the start and end points.  It then randomly displaces this midpoint by a distance equal to Maximum Distance.  There are two line segments now -- segment joining the start point and the midpoint (AM) and the segment joining the midpoint and the end point (MB).  This completes the first iteration of this procedure.   To enter the second iteration, Insectoids scales the distance value used in the previous iteration (MaximumDistance) by Roughness % to get the new distance value.  It then randomly displaces the midpoints of the two line segments by the new distance value. There are four line segments now.  Insectoids continues this process until the required number of iterations is reached or the length of the line segment is lesser than the insect size.  The random path is the line joining the start, all the randomly displaced mid points, and the end point.

Local Path Parameter Description
Maximum Distance A larger Maximum Distance makes the insect fly more distance (and slower) than a smaller Maximum Distance value. 

The default Maximum Distance value is 10

Roughness % Roughness % is the amount by which Max Distance drops with every iteration.  A large Roughness % will cause Maximum Distance to drop slower and a small Roughness % will cause it to drop faster.  If you want your insects to flutter a lot, have a large Roughness %.  If you want them to move smoothly use a small Roughness % value. 

The default Roughness % is 50

Iterations Iterations determine the number of points that will be present on the path and thus the suggested number of frames required to traverse these points.  A lower iteration value creates lesser points enabling the insects to fly faster.  A higher iteration value creates greater number of points causing the insects to fly slower

The default Iterations value is 6

From Insect Size If turned on, the number of iterations is determined at run time.  Insectoids stops at the iteration when the length of the path segment being subdivided becomes less than the Size of the insect.  Note that the Iterations text box will be disabled when this parameter is turned on.

By default, From Insect Size is turned off.

To All buttons You use the To All button to copy the value of a parameter to its counterparts in other stages. 


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Copyright (c) 1998 Jaganathan Sampath
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This page was last updated on: December 9, 1998
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