WorldCAD Access

Execs to Obama: Reform Patents, Pls.

24 tech execs, including Carl Bass of Autodesk, signed a letter asking for the American president's support on patent legislation now in the American congress, which would:

• Rreduce damages for patent infringement.
• Reduce court shopping.
• And other things not specified in the Reuters article. 

Autodesk is apparently the only CAD vendor to be a member of Coalition for Patent Fairness.

Source.

Geometric Patents 3D Searching

The USPTO grants Geometric patent #7,397,473 for searching 3D models based on shapes. 3DSearchIT works like this:

1. Prior to the search, the software generates 3D grids of the 3D models, and then computes 2D projections. The 2D projections are combined into 2D hierarchical representations, and then stored.
2. During the search, the software determines the similarity between two 3D shapes by comparing key coefficients of corresponding 2D hierarchical representations. 

Want to write your own 3D search engine? You’ll need to be familiar with discrete Fourier transforms, the Harr wavelet transform, and principal component analysis. The patent lists other systems of 3D searching and their limitations:

Statistical shape-based methods sample a large number of sample measures; the drawback is that their discriminating power decreases rapidly with increases in the number of models in the repository.

Graph-based methods generate connected skeletal approximations; the drawback is that it is difficult to adapt this method to models with multiple bodies or with surfaces.

Transform-based methods generated approximations of 3D models; the drawback is that their approximations are too indiscriminating for large repositories of models.

3DSearchIT works with parametric surfaces, polygonal facets, mesh approximations, and point-cloud approximations, from which it derives surface data. Inventor Tathagata Chakraborty has this to say about his method:

It has been observed that a small set of 2D projections, of sufficiently high resolution, can capture many key characteristics of most 3D CAD models, thereby providing a robust as well as an efficient paradigm to compare their shapes.

3dsearchit.geometricglobal.com

Do Little CAD Companies Patent?

We expect the IBMs and Autodesks of the world to generate patents, but what about the smaller CAD companies. I looked for and found a few:

Alibre

"Modeling three-dimensional objects on a computer system via a high bandwidth distributed network, facilitating the computing of intensive computer-aided design (CAD) tasks to take place on a series of servers." Patent number 6748419.

IronCAD

"...editing handles for solid shapes." Patent number 6781597.

Cadkey, Keycreator, Kubotek, Datacad, Graphisoft, VectorWorks

None. But some of these vendors might have patents in other countries.

Other smaller CAD companies, like Bentley Systems and CoCreate/HP, have a dozen or more patents.

Bonus: here is the flying machine patented by Orville Wright in 1903: patent number 821393. I wonder if the drawings are good enough to recreate the airplane?

RevCloud Patented

Autodesk in 2003 received a US patent on the RevCloud command's ability to draw a redline shape made of arcs. The patent describes a method of determining the arc's size by the first arc drawn while the mouse button or Shift key is depressed:

the bulge spacing function comprises setting the bulge spacing for the multiple arc segments equal to the bulge spacing of a first arc segment when:
* a first point of the first arc segment has been selected;
* an arc defining key has been depressed and held down; and
* a second point of the first arc segment is selected.

Source: Intelligent drawing redlining and commenting feature.