Sketch

Sketch

Copyright © 2005, 2006, 2007, 2008 Eugene K. Ressler.

This manual is for sketch, version 0.2 (build 89), Tuesday, May 27, 2008, a program that converts descriptions of simple three-dimensional scenes into static drawings. This version generates PSTricks or PGF/TikZ code suitable for use with the TeX document processing system.

Sketch is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version.

Sketch is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with sketch; see the file COPYING.txt. If not, see http://www.gnu.org/copyleft.

• About sketch: Why sketch exists and what it does.
• Introduction by example: Most features shown as working code.
• Input language: Syntax and semantics of sketch commands.
• Building a drawing: How to use sketch productively.
• Command line: Options and their usage.
• Installing sketch: Building and installing from sources.
• Index of syntax
• Index

--- The Detailed Node Listing ---

About sketch

• Reporting bugs: Let use know what's wrong!
• Contributions: How you can help....

Introduction by example

• Hello world: Simplest possible sketch program.
• Drawing options: Controlling object appearance.
• Drawing a solid: Drawing an object with 3d appearance.
• Special objects: Laying TeX over, in, or under drawings.
• Object transforms: Rotate, translate, scale, and others.
• Repeated objects: Making transformed copies.
• Swept objects: Sweeping objects in space to make new shapes.

Swept objects

• Point sweeps: Swept points make lines and polygons.
• Polyline sweeps: Swept lines make surfaces.
• Nested sweeps: Swept sweeps are useful!
• Polygon sweeps: Swept polygons make solids...
• Polyline sweeps with closure: and so do closed polyline sweeps.
• Affine arithmetic: Sketch useful math expression.
• More to learn: Check out the Mobius strip!

Input language

• Language basics: Case, space, comments, include files.
• Drawables: Things that can be drawn.
• Definitions: Giving things names.
• Global environment: Affect the entire drawing.

Basics

• Identifiers: Names for things.
• Key and reserved words: Names you shouldn't use.
• Literals: Constants and constructors.
• Arithmetic: Rules for expressions.
• Options: Modifying object appearance.

Literals

• Scalar literals: Just the numbers.
• Point and vector literals: 3d quantities.
• Transform literals: Matrix form.

Arithmetic expressions

• Two-operand (binary) forms: A op B
• Unary forms: op A (and others)

Options

• PSTricks options: Options inherited from PSTricks.
• TikZ/PGF options: Options inherited from TikZ/PGF.
• Dots in TikZ/PGF: Sketch uses TikZ/PGF circles for dots.
• TikZ/PGF user-defined styles: Support for TikZ/PGF named, user-defined styles.
• Transparency: See-through polygons.
• Internal options: Options used by sketch.

Point lists

• Drawables: Things that are drawn.
• Definitions: Things with names.

Drawables

• Dots: Draw dots.
• Lines: Draw polylines.
• Curves: Draw curves.
• Polygons: Draw polygons.
• Specials: Embed raw LaTeX and PSTricks.
• Sweeps: Draw sweeps of dots and polylines.
• Blocks: Group other drawables.
• Repeats: Draw transformed copies of objects.
• Puts: Draw one object transformed.

Sweeps

• Swept points: Swept points make lines or polygons.
• Swept lines: Swept lines make open or closed surfaces.
• Swept polygons: Swept polygons make closed surfaces.
• Swept blocks: Swept block == block of sweeps.
• Sweep face splitting: Fixing warped faces with triangles.

Definitions

• Forms of definitions: Different defs for different purposes.
• Forms of references: How references denote types.

Global environment

• Global options: Attributes of the entire drawing.
• Camera: A final camera transformation of the scene.
• Picture box: Setting the bounding box and 2d clipping.
• Frame: Adding a box around the drawing.
• Language: Setting the output language.

Building a drawing

• Overview: Building a substantial drawing.
• A technical drawing: An example with fine placement.
• A hierarchical model: An example with sweeps and puts.
• Caveats: Where trouble can occur.

Caveats

• Limits on error detection: What sketch doesn't do.
• Clipping: No clipping at present.
• Hidden surface removal: Imperfections to fix.

Hidden surface removal and polygon splitting

• Statistics: Performance numbers on depth sort.
• Bugs and anomalies: Imperfections in this implementation.