topic Re: Applying mathematical formula in a C++ Objectarx program in ObjectARX Forum

Applying mathematical formula in a C++ Objectarx program

nggarnaud — Thu, 23 Aug 2018 20:38:54 GMT

Dear all

I trying to enhance the creative capabilities of my custom entity by using some mathematical formula ( such Hamilton system, and Casteljau algorithm). At this level of development, i trying to applying what i learnt from Gerald Fairn Book's Curves and Surfaces For Computer Aided Design Geometries. Does anyone has experience applying mathematical equation in an Objectarx program written with VS 2015?Thank you in advance. Gil

Re: Applying mathematical formula in a C++ Objectarx program

thierry_prince — Fri, 24 Aug 2018 10:18:22 GMT

Hi,
I'm sorry, but I don't understand what you mean with "applying mathematical equation in an Objectarx program".
Can you give more explanations, or a small sample ?
Bye.

Re: Applying mathematical formula in a C++ Objectarx program

tbrammer — Thu, 30 Aug 2018 19:44:59 GMT

So you have implemented a custom entity and I suppose it shall display Bezier curves within it's subWorldDraw() method. Right?

What you have to do is to implement the De-Casteljau algorithm to calculate polygon points and then draw the polygon in subWorldDraw().

Your custom entity could also display and the control points as grips by overwriting subGetGripPoints() and you can drag their positions if you implement subMoveGripPoints().

Re: Applying mathematical formula in a C++ Objectarx program

nggarnaud — Fri, 31 Aug 2018 00:04:37 GMT

Hello tbrammer,

Thank you for your feedback. I will give it a try, and let you know how it goes. Cheers