Just joined, hobby level

[Jonathan]

You beat me to it, nice explanation! I used the same method with vectors in my wind turbine blade profile and tool-path calculation program. Using the equation for a NACCA airfoil, which doesn't simplify as nicely.

[black5f]

You beat me to it, nice explanation! I used the same method with vectors in my wind turbine blade profile and tool-path calculation program. Using the equation for a NACCA airfoil, which doesn't simplify as nicely.

Cheers! Sounds lke a nice project, hope you differentiated the eq to get the tangents ;-) Somewhere I still have the source I wrote for a surface model with 310 bicubic patches. That a patch bounded by four cubic splines (48 coeficcients) (just in case!), all continuous with each other. I had algorithms to calculate the normals at any point (for shading), integrals for area, routines that solved the intersections of them with planes for crossections. And, believe it or not, it ran on a BBC model B because the IBM pc hadn't been invented yet! I remember rewriting it in pascal for the pc.
Tom

[cncgcg]

Hi Tom,
Thanks for all the work you put into the reply, it will keep me going for ages. The last time I had anything to do with matrixes was rotating wire frame graphics, also on a BBC B 32k which I bought Christmas 1983, for a months wages I think, from the NAAFI in Bielefeld where I was posted. Prior to that, in school, where we did them endlessly it seemed, and never knowing why.

Gareth

[black5f]

Hi Tom,
Thanks for all the work you put into the reply, it will keep me going for ages. The last time I had anything to do with matrixes was rotating wire frame graphics, also on a BBC B 32k which I bought Christmas 1983, for a months wages I think, from the NAAFI in Bielefeld where I was posted. Prior to that, in school, where we did them endlessly it seemed, and never knowing why.

Gareth

It's bizar really, probably I'm getting old. I learnt all the maths at Uni but never really saw the point. We had a computer but you had to puch holes in bits of card! When I started looking into CAD/CAM possibilities in my industry I started off, then there was a day when suddenly I started to recognise stuff, got out my old notes and there it was!

I've bene interviewing Maths grads recently and none of them have ever coded anything? If I ran a maths course, I'd start with one frame from star wars, zoom in on a bit 100 by 100 pixels and start explaining the maths behind it. A lot more engaging!

There's a really good book I used in the 80's, I see now it's on the 8th addition of something. There should be loads of these 2nd hand as they are the bible. It assumes very little, work through it from the start and it gently introduces stuff, with examples. I have a selection but they are all at work, I'll write a list later!

http://www.amazon.co.uk/Engineering-...2918706&sr=8-2

There are others but they assume a lot!

Tom