>
> Desiree,
>
> I have only just started to look at this but a few initial comments come to
> mind.
> These points will not help (much) but could make a little difference in
> similar applications.
> My points are not about Z buffer (that comes later) but are with respect to
> accurate positioning
> of objects in relation to each other, and accurate relative movement.
> 1) You are just going over the limits of single precision floating point
> (SPFP). Generally you
> only get the equivalent of 6 to 9 decimal digits of precision from SPFP. This
> sounds odd but
> I did a few articles on this subject (in reference to VRML) to explain this.
> The math precision
> issues addressed in the articles should be applicable in general.
> 2) If you centre the models over 0,0,0 you can, in my mind at least, gain a
> little more overall precision
> as you are using the available precision for both negative and positive SPFP
> numbers.
> 3) Because of the above, when operating with such large models you may be
> better off using doubles.
>
Hi Chris,
my real planes in the application do have a GeometryArray filled with
Point3d.
if (geom instanceof GeometryStripArray) {
GeometryStripArray tri =
(GeometryStripArray) geom;
geo"+tri.getNumStrips());
vert = new int[1];
tri.getStripVertexCounts(vert);
// Change the represenation of the axes
towards
// 3D-Service
GeometryArray geomarr = (GeometryArray) geom;
Point3d[] point3d = new Point3d[vert[0]];
for (int i=0;i<point3d.length;i++) {
point3d[i]= new Point3d();
}
geomarr.getCoordinates(0,point3d);
// Change [Wed Mar 28 16:04:57 2001]hilbring:
point3d =
transposition.java3DToWorld(point3d);
wv =
transposition.calculateWorldVolumeFromJava3D(point3d);
geomarr.setCoordinates(0,point3d);
}
I am using VisAD for the construction of the layers. And
constrcutor of the Irregular2DSet just accepts floats.
Desiree
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