Geometric Modeling - Boundary Representations (BREP)

[@chrischoir3594]

This is the best CAD related video on the internet. I wish you would do more of them.

[@devanshroyal8372]

This is by far the best educational video I've seen

[@lifeisgood24917]

Why can't we have teachers like you?? I mean this was taught in our class(or maybe not) but this 8 minute video compensated for long long lectures..! Thank you.

[@mihailazar2487]

As I find myself at the crossroads before setting off on the journey of writing my own CAD system, this video has been the single best resource I've ever come across To be honest, I had a sneaky suspicion that's how CAD programs worked under the hood, through experience with a lot of them, and some analytic geometry But this video really confirmed much about what I was suspecting and also clarified a few details such as why you need a different abstraction for a shell and a solid: because as you said, we need to be able to represent objects with internal cavities

[@janetgray8868]

Absolutely love your videos. Do you have boundaries? I learn sooo much from you. You are a great teacher. Keep it up.

[@balajiram2755]

Brilliant ! Such simple explanation of BRep. Thank you.

[@swamihuman9395]

Late to the party, but GREAT JOB, Glen! Clear, concise, and at times, amusing ("Borderline", & "Outer Limits": HAHA!:)). [FYI, 3ds Max supports BRep import/creation/export, though I don't know to what extent, as this feature is new to me. I have v2016, but suspect BRep came earlier. Also, fun historical note: I started in 3D Studio r2, in early 90's! Have loved 3D from the beginning, plus its amazing progression over the years.]

[@MrLunchbox88]

Great video. Keep them coming. Really helpful for students with dodgy professors :)

[@fritzschnitzmueller3768]

Your videos are really good content

[@henmich]

I laughed at the song... That's a dad joke of the highest order... 50 points to gryffindor!

[@chrischoir3594]

you definitely need to make more videos and you need to write a book

[@ryanmelvaer1007]

Great video. Thanks for the explanation. I loved the song choice for the intro/outro.

[@syntaxed2]

Incredible information, thanks man! Quite amazing how much there is to learn thanks to the internet...well, thanks to the american-english alliance our lives are so much better :D You guys made everything I love.

[@manishshah2179]

Great Video. It is really helpfull

[@gnagyusa]

Ah, the old ways of CAD. Thank goodness for Catmull-Clark subdivision and boolean operations. They let you just model / sculpt your design directly and intuitively, rather than doing it the old, indirect and convoluted way. We are building an anatomically based humanoid robot, with tons of complex parts that are blended between organic and geometric shapes. It would take 10 times longer to do with B-rep and we'd be tearing our hairs out. Good video and good explanation though.

[@math4every1]

Catmull-Clark is good for imaging (Pixar uses it) but not very good for CAM because of the lack of a usable parameterization.

[@fslurrehman]

Hi Glen Gray, Can you recommend a book on applied brep that describes all of its math. Which one can use to make a CAD software package 📦. Also please share the reference of this video. Best regards, FR

[@math4every1]

There are a number of good books out there. If you want a good general introduction I would suggest "Geometric Modeling" by Michael Mortenson and "Computational Geometry for Design and Manufacture" by Faux and Pratt. There is no book that is going to give you all the details involved in generating a geometric modeling package. There are literally volumes of journals with articles addressing specific problems you will encounter. The two best journals out there are "Computer Aided Design" and "Computer Aided Geometric Design". Also if you wish to base your geometric system on NURBS geometry I would suggest "The NURBS Book" by Piegl and Tiller. I have been writing CAD software for 30+ years. Not that I am trying to dissuade you but consider one of my coworkers has been working on solid fillets (a single CAD operation) for over 20 years and there is no end to all the cases in sight.

[@stephfong4577]

Where do we store curve equations? Or how is curve equations stored?

[@math4every1]

The method used for curve storage will vary from package to package. Some will use a hybrid approach and store conics analytically along with their favorite spline, while others will use strictly a spline model for all curves. For example Non-Uniform Rational B-splines (NURBs) are able to model conics exactly but take more storage for simple conics. The disadvantage of a hybrid approach is that all low level curve operations will need to break off into multiple cases requiring more code and support.

[@bravelittletoaster3439]

Haha. The song. 😀

[@BENDENDERMAN]

brep

[@jamesrockford2626]

the madonna has to go