Just finished an article that introduces TCad's "Surface from Law" tool. Fifty-three pages, 49 illustrations, and a bazillion mathematical formulas. This is a mathematical tool and there's no way to treat it non-mathematically, but anyone who's comfortable with high-school algebra and understands sines and cosines should have no trouble following the article. Staying awake is another matter. The article isn't really a tutorial; more like a short textbook, but heaven knows there are many more aspects of this tool than I touched upon.

Download it here.

Henry H

EDIT: The table on Page 17 contains errors. I have deleted the original article and attached the corrected version in its place. I've also attached a screenshot of the corrected table.

Gave it a quick once-over and read a couple pages; it is a fascinating primer on how to use this functionality.

Thanks, Henry.


Jeff

Wow, thanks for doing this Henry.

Only had a quick look up to now as its going to take reading it quite a few times to try and sink in to my non-mathematical brain.

Henry,

thank you.
I'm looking forward to studying your latest . . . whatever!

Regards Tim

Thank you very much Henry, it's completely Help to this tool

Thanks for the tutorial Henry. This is just one reason to brush up on math, the other one is astronomy (measuring binary stars). I haven't checked but do the other CAD programs have a similar "Laws" tools, I sure they do. (Autocad, Solidworks, ect.)

Impressive short txt book Henry...Thank you to help us out with this!!

Henry,

Thank you for the excellent document!

btw, it appears that using the sqrt function in the Surfrace from Law tool causes tcad to crash, like, z(u,v)=sqrt(u*2)

Has this happened to anyone else?

Thanks
Kevin

Henry,

Thank you for the excellent document!

btw, it appears that using the sqrt function in the Surfrace from Law tool causes tcad to crash, like, z(u,v)=sqrt(u*2)

Has this happened to anyone else?

Thanks
Kevin

I've had problems with the sqrt function, too. Instead of sqrt(x), I now use abs(x)^.5 with no trouble.

Henry H

Not sure why but abs(u)^.5 is not working for me either.

Not sure why but abs(u)^.5 is not working for me either.

Care to post the X, Y, and Z Laws you're working with?

Henry H

Certainly,

Using the Surface from Law tool, I used

x(u,v) = u
y(u,v) = v
z(u,v) = abs(u)^.5

Thanks
Kevin

I should note to that the crash does not show up until you click on the model space.

Certainly,

Using the Surface from Law tool, I used

x(u,v) = u
y(u,v) = v
z(u,v) = abs(u)^.5

Thanks
Kevin

Strange. Works fine for me.

Henry H

Crashed for me also. It generated a UE and sent the report to SoftDev.

On a second crash, I answered "No" and copied the M$ report.
Problem signature:
  Problem Event Name: APPCRASH
  Application Name: tcw23.exe
  Application Version: 23.0.23.1
  Application Timestamp: 56f9cbca
  Fault Module Name: MSVCR100.dll
  Fault Module Version: 10.0.40219.1
  Fault Module Timestamp: 4d5f034a
  Exception Code: 40000015
  Exception Offset: 00000000000761c9
  OS Version: 6.0.6002.2.2.0.256.6
  Locale ID: 1033
  Additional Information 1: c457
  Additional Information 2: d152718b5945b031752a3c3117d3d332
  Additional Information 3: 7791
  Additional Information 4: 568dad990b75121c0f3882a6e539fd4b

It worked ok for me, using Henry's image
The other shape has six sqrt(2) in the formula = no problem either.

What version are you using, kevin, 32 or 64 bit?
Maybe something got corrupt, though I would double check your formulas.

I tried the formula in Windows 10 and it crashed there.

Vista w/Platinum 64bit - crashed
Win 10 w/Platinum 64bit - crashed
Win 7 w/Pro Basic 32bit - no tool

I was using 64 bit before, but, I just installed the 32 bit on Win 7 w/Platinum and getting the same error that I did on the 64 bit version.

I was using 64 bit before, but, I just installed the 32 bit on Win 7 w/Platinum and getting the same error that I did on the 64 bit version.

Ok,
I think I found the "Bugger"
> see attachment try these "ACIS" setttings > before you create the law 

Hey, that worked !!   

Thanks!

Kevin

re: …try these "ACIS" settings before you create the law.

I think you only need to turn "Degenerative Faceting" OFF.

Thank you Dean for the useful info.

Amazing Henry...Thanks!

re: …try these "ACIS" settings before you create the law.

I think you only need to turn "Degenerative Faceting" OFF.

Thank you Dean for the useful info.

Yup. That's it. I almost never have Degen ON.

Henry H

Hi Henry,

Is this a "2016" tool only, or is it present in 2015?
 
BG

Hi Henry,

Is this a "2016" tool only, or is it present in 2015?
 
BG

It's new in 2016, Bill.

Henry H

Hi Henry,

Is this a "2016" the bathmate tool only, or is it present in 2015?
 
BG

Looks like a great tool thanks! Are there any video tutorials of how to use it anywhere?

Looks like a great tool thanks! Are there any video tutorials of how to use it anywhere?

There are a couple of short video's done by IMSI, they are more of an overview than a tutorial.

https://www.youtube.com/watch?v=uLkOF9pW4H0
https://www.youtube.com/watch?v=z9eQZCppJ5s

Just by chance I saw a video about Surface Laws and by coincidence I found this thread and downloaded it and like everyone else read it word for word but I can't seem to find which toolbar or drop-down window the Law is found in.  I looked on the 2016 desktop and looked at all the toolbars and menus and I can't find it.

John B.

Hi John,

Draw - 3D Object - 3D Law Object

Cheers
David

I went to Draw/3D Object but there was no 3D Law so I looked in Customize/Commands/3D Object and found Surface With Law and dragged it to Draw/3D Object and pasted it there.

Cheers David,

John B.

Page 17 of the article contains some errors. My thanks to Igorun for finding them. See the original post at the top of this thread for corrections.

Henry H

I finally got around to start reading this article. Thanks Henry it is a fantastic article

I finally got around to start reading this article. Thanks Henry it is a fantastic article

Thank you, Nikki.

Henry H

That borders on a doctoral thesis!
Thank you Henry.

Thanks Henry.

I have a small guitar part (a truss rod cover) whose shape follows a parabola with formula y = 1/3 x^2. [I don't think that this is a concidence because the designer, Brian May, was a maths whizz!] It can be created easily enough with a spline or bezier curve, obviously, but I did wonder while designing this whether it was possible to create a complicated object such as a surface from a law/mathematical expression.

I will take a look at this when I have some spare time. It might prove useful in future endeavors.

Doug