Re: Fw: [x3d-public] Size of live Box

["George Anastassakis" <anastas@unipi.gr>]

> AFAIK, there is no way to do this currently specified. See the February 
> thread "Bounding box of live X3DNode" in the list archives.

I believe that thread was about getting a bounding box (or, better put, 
limits, depending on what model's internally used) for any given geometry 
node. Instead, I'm talking about the very size of primitive geometry nodes 
to calculate the bounding boxes myself (in fact, said thread was the reason 
I started writting my own bounding box calculation code). For such nodes, 
size is very well defined by a number of fields and cannot change in any way 
other than modifying the field values themselves (which could still not be 
allowed even if the fields where readable), neither would it's availability 
make browser implementors adopt any specific approach as to anything (in 
contrast to providing live bbCenter and bbSize values). So I don't see the 
point in hiding their values.

I also find some contradiction here: Boxes, spheres, etc. are geometry nodes 
as are, for instance, IndexedFaceSets. Live coordinates are available for 
the latter (not to mention that they can change through SAI as Coordinate's 
point is an inputOutput field). On the other hand, the fact that the fields 
used to internally generate coordinates for boxes, spheres, etc. are not 
readable means that the actual geometrical properties of geometry nodes such 
as boxes, spheres, etc. cannot be known while the geometrical properties of 
other geometry nodes such as IndexedFaceSet can.

Anyway, point taken, the X3D spec does not allow reading the fields that 
define the size of boxes, spheres, cones and cylinders (if I'm not 
forgetting any), although I must admit I still cannot understand why.


George

> Braden
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