Introduction This tutorial explains mcjBuilderA extrusion-path-script writing To describe mesh creation, we use the analogy of "extrusion"
some solid material is pushed through an imaginary hole/nozzle
The shape of this nozzle is referred to as the "extrusion profile" or "molding shape"
 In mcjBuilderA's "Settings for molding profile" panel, you can select a molding profile using the drop-down-list Labeled "Profile"
The chosen profile in our example is named "f"
The mold Width is 100 cm and the mold Height is 100 cm,
The red cross shown in the "blackboard" panel indicates the origin [0,0] of the shape
the extrusion path will pass through this point.
 mcjBuilderA suggests we use a height of 167cm if we intend to keep the original proportions
 the initial position of the nozzle in the scene is ( 0, 0, 0 )
the initial rotations of the nozzle are ( 0°, 0°, 0° )
the nozzle's plane is standing up ( like the green arrow Y axis )
and facing the Z axis ( blue arrow )
If the path-extrusion script started with a "Move 1" command
which means "move forth 1 step" then
the extrusion nozzle would advance along the Z axis ( blue arrow ) by 1 step
  in mcjBuilderA's "Settings for extrusion path" panel. the "Tread" parameter was set to 100 cm,
so the command "Move 1" resulted in a 100cm long extrusion.
the term "tread" comes from the stair design terminology" because mcjBuilderA started as a stair handrail builder script
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"ring" and "move" : making straight tubes lets look at the extrusion path script
Y ( green arrow ) is the up axis
so "
Move Y 0.855" means move the nozzle up by 0.835 stepsince Tread is 100 cm, it meant move the nozzle up 83.5 cm
remember we made the profile 167 cm tall earlier
half of the nozzle was initially below ground level, it's now entirely above ground
Ring This creates the first ring of vertices of the molding!
Move 1 Moves the nozzle forth 1 x 100 cm
Ring This creates the second ring of vertices of the molding, so we now have a molding segment
The "Paste Settings" button : Saving everything in the previous example, we did set the mold width and mold height
But lets say, one month from now we want to build our F shape again
nothing tells us what the values for mold width and mold height will be
and maybe we wont even remember what values we used
So we will make all the settings part of the script
starting with version Beta 6 there is a button labeled "paste settings" which will paste all the current settings in your script box
"define" : defining something for easy re-use using the
define command you can give a name to a block of commandsalong with the name of the defined block, you can supply a list of parameters
in the example below, we give the name "segment" to a block of 3 commands
and we state that it will be accompanied with 1 parameter named "d"
note how we then use "d" in the "
move" commandthe command "
defineEnd" signals the end of the block
so from now on, we simply type
and we'll get a segment of length 4
break : break it into pieces issuing the break command ... breaks the extrusion path
you can then move the nozzle elsewhere and make a new tube
so here we
 "material" : one material a piece now that we know how to break a path into multiple objects we may want to give each piece a different material
when you dont use the "material" command, everything in your molding uses the material named "default
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