[open_cad_format] Re: [freearchitecture] Re: Re: x3d-cad vs. step

[Lars O. Grobe]

> i think yes; you can append properties to objects or include the code as 
> user-data.
> 
> Geometric programs are a sequence of computations and geometric operations. 
> You need to have a environment with:
> - programming-functions (variables, loops, comparisons, subprograms, IO)
> - geometrical functions (rotate point, get tangent of curve, intersect..)
> - and functions to create objects.
> 
> For this you need a description(language).

I found that in Express you can actually reference values. E.g. you 
define a line not as (0,0,0) to (0,10,0) but as (a,b,c) to (d,e,f) and 
create or calculate the values for a-f somewhere else. There are 
numerical operations available among others.

Now, for making this useable in real world, one would need a library of 
procedures e.g. to find intersection points, test for collision / 
overlaps etc. This library still could also be written in Express, thus 
be a step file, right? So making parametric object cross-platform and 
cross-application could start out to be defining the procedures such a 
library should make available. Than step files containing parametric 
objects (code like the one generating my stair) could rely on these 
library functions, which must be standardized, and in case this lbrary 
does not exist I just have to send one more Step-file containing the 
library - right?

Can Express-procedures call external applications? If yes, how secure is 
this?

I am getting more and more excited by this ;-)

CU Lars.