Hacker News Reader

Comment by s1mon | Hacker News Reader

Evans and Sutherland also developed CDRS (Conceptual Design and Rendering System) which was later bought by PTC and developed into ISDX. This is a 3D CAD tool for high quality surfacing used by industrial designers and surfacing experts to develop exteriors for automotive and consumer products. It was originally written in Lisp.

Unlike many other CAD tools, especially for its time, it described the relation between surfaces as a bunch of rules. So surfaces 'A' and 'B' could influence 'C', and then the user change their mind and decide that 'C' should drive 'A' and 'B' instead. Unlike other parametric tools which would come later, you didn't set this up by reordering a bunch of features, you just changed the connection icons between the surfaces. It was up to CDRS to figure out what order to solve the constraints and build the surfaces.

View on HN

Right out of high school I started as an intern at PTC in Research Park shortly after they acquired CDRS from E&S.

CDRS was originally started by some of the researchers from the University of Utah that created the Alpha_1 NURBS modeler.

After PTCs org wide rebranding, it was called Pro/Concept.

I worked on the other product in the group called Pro/3D Paint. It was the first product to use projective texture mapping to allow industrial designers to draw directly on 3D models instead of in texture space.

So many more memories I wouldn’t know where to begin…

When was that?

I mentioned in another thread I used alpha_1 in high school at the U (2002). I had actually had Autocad (R16) 3D CAD experience at the time, but alpha_1 was a lot of fun. I ended up making a 3D Model of Escher’s Belvedere. One of the guys was going to “print” it down in the lab in the bottom of MEB (they did have some form of 3D printer) but thought it might be hard and unstable. I ended up getting it rendered with ray tracing on one of the brand new UltraSPARCs they had in the lab, and it was printed on a T shirt that everyone got. We also got a copy of VisualStudio 6 from Microsoft (we toured their studio near the airport) which I sold on ebay for $375 at the time.

I don’t know the exact year the CDRS group was acquired by PTC, but it be around the same time I attended the same High School Computing Institute in 1996.

PTC made the purchse in 1994 ... it's a great story if you want to hear it....

Bart Brejcha Design Engine

I started using ISDX in ‘96 soon after PTC acquired it and managed to port it and make it work with Pro/E. I’ve worked on a number of products which are still in production using it, but it’s been a while since I was using Pro/E (now Creo). I don’t miss Creo, but I do miss ISDX. There was a while when I was using Solidworks and Pro/E (with ISDX) depending on the project/client, but then I transitioned to Solidworks for many years. Now I’m using Onshape (started by the key people from Solidworks) which recently was acquired by PTC. Both Solidworks and Onshape use the Parasolid kernel which was first developed for Unigraphics. It seems like it’s a small world in CAD tool development.

I used CDRS while at Caterpillar in 1997 and purchased it in the same year not knowing it was slated for the graveyard. I made it my mission to be the expert ... luckily STYLE became the cool new thing in 2001 and I was able to be expert in that right away.

Bart Brejcha Design Engine

Reply on news.ycombinator.com