75 lines
3.2 KiB
ReStructuredText
75 lines
3.2 KiB
ReStructuredText
.. _designprinciples:
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===========================
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CadQuery Design Principles
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===========================
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Principle 1: Intuitive Construction
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====================================
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CadQuery aims to make building models using python scripting easy and intuitive.
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CadQuery strives to allow scripts to read roughly as a human would describe an object verbally.
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For example, consider this object:
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.. image:: _static/quickstart.png
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A human would describe this as:
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"A block 80mm square x 30mm thick , with countersunk holes for M2 socket head cap screws
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at the corners, and a circular pocket 22mm in diameter in the middle for a bearing"
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The goal is to have the CadQuery script that produces this object be as close as possible to the English phrase
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a human would use.
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Principle 2: Capture Design Intent
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====================================
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The features that are **not** part of the part description above are just as important as those that are. For example, most
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humans will assume that:
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* The countersunk holes are spaced a uniform distance from the edges
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* The circular pocket is in the center of the block, no matter how big the block is
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If you have experience with 3D CAD systems, you also know that there is a key design intent built into this object.
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After the base block is created, how the hole is located is key. If it is located from one edge, changing the block
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size will have a different effect than if the hole is located from the center.
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Many scripting languages do not provide a way to capture design intent-- because they require that you always work in
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global coordinates. CadQuery is different-- you can locate features relative to others in a relative way-- preserving
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the design intent just like a human would when creating a drawing or building an object.
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In fact, though many people know how to use 3D CAD systems, few understand how important the way that an object is built
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impact its maintainability and resiliency to design changes.
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Principle 3: Plugins as first class citizens
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============================================
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Any system for building 3D models will evolve to contain an immense number of libraries and feature builders. It is
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important that these can be seamlessly included into the core and used alongside the built in libraries. Plugins
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should be easy to install and familiar to use.
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Principle 4: CAD models as source code makes sense
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==================================================================
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It is surprising that the world of 3D CAD is primarily dominated by systems that create opaque binary files.
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Just like the world of software, CAD models are very complex.
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CAD models have many things in common with software, and would benefit greatly from the use of tools that are standard
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in the software industry, such as:
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1. Easily re-using features between objects
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2. Storing objects using version control systems
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3. Computing the differences between objects by using source control tools
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4. Share objects on the Internet
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5. Automate testing and generation by allowing objects to be built from within libraries
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CadQuery is designed to make 3D content creation easy enough that the above benefits can be attained without more work
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than using existing 'opaque', 'point and click' solutions.
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