3PTARB(nged)

💅 3PTARB(nged) — the BRL-CAD User Commands era

okay bestie, so this is a page from the BRL-CAD User Commands manual, and it's literally about making an ARB8 shape. buckle up 🎀

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✨ NAME ✨

3ptarb — build an ARB8 shape by extruding a quadrilateral through a given thickness. yes that's the whole vibe. 🦋

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🌸 SYNOPSIS 🌸

3ptarb [arb_name] [x1] [y1] [z1] [x2] [y2] [z2] [x3] [y3] [z3] [x/y/z] [coord1] [coord2] [thickness]

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💖 DESCRIPTION 💖

So here's the tea ☕ — you're building an ARB8 shape by extruding a quadrilateral through a given thickness. iconic behavior, honestly.

The arguments can be handed to it right on the command line, but like... if they're not? it will literally prompt you for them. no cap, it's very patient. 🫶

Let's break down who's who:

• x1, y1, z1 — the coordinates of one corner of the quadrilateral. main character corner.
• x2, y2, z2 — coordinates of a second corner.
• x3, y3, z3 — coordinates of a third corner.
• x/y/z — the parameter that tells the code which coordinate of the fourth point it should calculate.
• coord1 and coord2 — the other two coordinates of that fourth point.

And here's the cute part: only two coordinates of the fourth point get specified, and the code calculates the third coordinate to ensure all four points are coplanar. it's giving "i got you" energy. ✨

The direction of extrusion for the quadrilateral is determined from the order of the four resulting points by the right-hand rule — the quadrilateral is extruded toward a viewer for whom the points appear in counter-clockwise order. 👑

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🌈 EXAMPLES 🌈

The following are run from the MGED command prompt:

🍓 Example 1. 3ptarb example with BRL-CAD prompting for information

mged> 3ptarb
    Start the 3ptarb command.

Enter name for this arb: thing
    The new ARB8 will be named thing.

Enter X, Y, Z for point 1: 0 0 0
    Point one is at the origin.

Enter X, Y, Z for point 2: 1 0 0
    Point two is at (1, 0, 0).

Enter X, Y, Z for point 3: 1 1 0
    Point three is at (1, 1, 0).

Enter coordinate to solve for (x, y, or z): z
    The code will calculate the z coordinate of the fourth point.

Enter the X, Y coordinate values: 0 1
    The x and y coordinates of the fourth point are 0 and 1.

Enter thickness for this arb: 3
    The new ARB8 will be 3 units thick.

🦋 Example 2. 3ptarb command as single line input

mged>3ptarb thing 0 0 0 1 0 0 1 1 0 z 0 1 3

Same as above example, but with all arguments supplied on the command line. one line, zero drama, slayed. 💅

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👑 AUTHOR 👑

BRL-CAD Team — kings, all of them.

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💀 BUG REPORTS 💀

Reports of bugs or problems should be submitted via electronic mail to devs@brlcad.org

like, if something's broken, tell them fr fr 📧

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a little sign-off from your girl: this page came to you courtesy of BRL-CAD and the 3PTARB(nged) manual entry — no extra date stamped on it, just the source and the name. go build something coplanar, bestie 🧚💜