Author: Laurence D. Finston
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Last updated: August 5, 2012.
Updated Sphere Model 2 : Added octagonal caps for the ends and matching pyramids to be attached to the caps. This is meant to solve the problem that it's difficult to attach the spherical biangles as they narrow to a point at the ends.
Started working on plans for Building Elements for paper or cardboard models.
Added a page for music with an example of how polyrhythms can be illustrated: Music.
Added a page for board games with a document containing empty chessboard and go board diagrams: Board Games.
Added a document with plans for a papercut: Star Spiral Pattern 1.
I've added a Geometric Patterns page with a section Papercut Patterns. On the latter, I have posted a document (along with the source code) containing patterns which may be of use for making papercut patterns (or similar kinds of patterns).
Added a third pattern on the Stellation Patterns webpage. I've also put all of the patterns into a single document.
Added collections of model plans on the models webpage. These are PDF files, plain and compressed (gzipped), in DIN A4 and DIN A3 format.
Added an Ellipsoid Models webpage. I'm currently working on plans for a model of an ellipsoid and I've posted the source code and files containing images on this page. However, this is a work-in-progress and the plans are still very incomplete.
Added plans for a third sphere model.
Added a Stellation Patterns webpage.
Added plans for a second version of a sphere model. This version has separate tabs, so the pieces are flush and don't overlap.
Added an Architectural Models webpage with plans for a paper model of the upper part of a clock tower.
Added a Models webpage with plans for a paper model of a facetted cone.
Added a Sphere and Dome Models webpage.
Added plans for a cardboard model of a Great Rhombicosidodecahedron.
Added a Curve-Drawing Machine Simulation webpage. It contains an example of a trochoid pattern.
Added plans for a cardboard model of a Great Stellated Dodecahedron.
Added more examples of interference patterns and a
flipbook with a
Started working on plans for a knitted dodecahedron model. (Note: Removed 2009.01.23.)
I've started working on sets of functions and parser rules for complex numbers and matrices. They use data types and functions defined in the GNU Scientific Library. GNU 3DLDF now links to this library if it is available. All code using the GSL is conditionally compiled, so 3DLDF should fail gracefully if the GSL is not available and a user tries to use any features that require it.
I have also added web pages for Complex Numbers and Matrices, but they are both under construction.
Started working on plans for a cardboard dodecahedron model with sundial faces. So far, I've only calculated the dial for a single face. However, there are diagrams illustrating the method. The files can be found on the Polyhedron Models page (Dodecahedra) or on the Sundials page (Dodecahedron Model).
Added pages for Catalan Solids (Archimedean Duals) and Rhombic Triacontahedron. The Catalan Solids (Archimedean Duals) page is under construction. The Rhombic Triacontahedron page has a sample of the net and a page with rhombuses for cutting out watercolor paper. The tabs also have markings for stitching the model together.
The same sample is included on the Polyhedron Models page.
Added links to 3DLDF, MetaPost, TeX, PostScript, PDF files, along with a couple of others, under Current Sample. Also added a link to a compressed (gzipped) archive file containing all of the source files and some generated files comprising the current sample: currsmpl.tgz.
Added an Origami and Paper-Folding page.
Added plans for a dodecahedron model on the Polyhedron Models page.
Added a web page for arcs. It's currently under construction.
Put first sample on the sundials web page. Will be revising it and adding explanatory text soon.
Added a web page for sundials.
Added a web page for polyhedron models. Not much on it yet.
Added a web page for Focuses. It's currently under construction.
Moved the examples of using the Braikenridge-Maclaurin Construction to the Conic Sections webpage. The Braikenridge-Maclaurin Construction is related to Pascal's Theorem. Given five points on a conic section, the Braikenridge-Maclaurin Construction can be used to find an arbitrary number of additional points. I plan to use this for finding the parameters of conic sections where only points are known. This will be useful in finding intersections and solving the problem of
apparent edges in perspective projection.
Added a Circles webpage.
Added an image of a double-napped cone with shadow on the Cones webpage. The parser rules and functions needed for making it are new.
It is now possible to set, transform, and draw right circular and elliptical cylinders and cones. I'm still working on the functions and rules for the ‘cylinder’ and ‘cone’ types. I've added web pages for : Cylinders and Cones, but I haven't gotten around to putting any examples in them.
Added an Important Notice.
Added a Wave Forms page.
Added pages for Elliptical Paraboloids, Hyperbolic Paraboloids, One-Sheet Hyperboloids, and Two-Sheet Hyperboloids. They are currently all under construction.
Added a Paraboloids page and a Hyperboloids page. They are currently under construction.
Added code for finding the intersection of a polyhedron and a plane. It is a polygon (except for the degenerate cases).
Added code for finding the intersection points of a polyhedron and a linear path.
Finished the non-default constructor for the Great Rhombicosidodecahedron. Added illustrations of it to the Great Rhombicosidodecahedron page.
Added text, illustrations, and code samples to the Cuboids page.
I've now implemented a way of finding the ellipse that represents the intersection of an ellipsoid and a plane. See the The Intersection Points of an Ellipsoid and a Plane for more information.
Added Polyhedra, Cuboids, Regular Platonic Polyhedra, and Semi-Regular Archimedean Polyhedra pages. They're currently under construction.
Added a Quadric Surfaces page. It's currently under construction.
Added a Prime Numbers page.
Adding a Conic Sections page.
Working on functions for finding the intersection points of a linear path and a hyperbola.
Adding parser rules and functions for parabolæ.
Added a Hyperbolæ page.
Started working on a web page for the 3DLDF language.
Added a Parabolæ page.
The ellipsoid data type now works. See Ellipsoid for more information.
The sphere data type now works. See Spheres for more information.
I have now removed all of the declarations and rules for
expressions, e.g., path_like_variable,
etc. These rules tended to cause conflicts, so I've decided to replace
them with separate rules for each type.
I've also removed the debugging code from the rules that I had
to change. This substantially reduces the size of the file parser.c++,
generated by GNU Bison from the parser input files. It is not possible
to break this file up into parts and compile them separately. The
length of time it takes to compile it is a bottleneck in development
and installation. I am therefore trying to reduce its size.
Removing these unnecessary rules and reducing the amount of debugging
code seems to have helped. I also plan to replace a lot of code in
the parser actions with function calls.
PLEASE NOTE: Since I've removed the code involving x_like expressions,
some things that used to work are temporarily unavailable. I will
be replacing the
collective rules that I've removed with individual rules
for the individual types. It will probably take me awhile before I've
replaced all of the ones that were formerly available.
Added a Sources section.
Added a Graph Paper (Plain and Perspective) page.
Added a Converting TeX Text to Images section.