Hello,
is there any possibility to generate a NURBS volume similar to the
NoTryPlanar-option which I can use for surfaces? I would like to obtain
the information regarding points and nodes of volumes.
Regards,
Georg
In GiD volumes are not NURBS volumes, they are defined by a closed
collection of boundary surfaces (are not ‘parametric volumes’)
I don’t understand well your question: what do you have and what do you want
to obtain?
Enrique
----- Original Message -----
From: “Georg Haasemann” georg.haasemann at tu-dresden.de
To: gidlist at gid.cimne.upc.edu
Sent: Monday, June 28, 2010 12:01 PM
Subject: [GiDlist] NURBS volume
Hello,
is there any possibility to generate a NURBS volume similar to the
NoTryPlanar-option which I can use for surfaces? I would like to obtain
the information regarding points and nodes of volumes.
Regards,
Georg
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Am Montag, den 28.06.2010, 14:28 +0200 schrieb Enrique Escolano:
In GiD volumes are not NURBS volumes, they are defined by a closed
collection of boundary surfaces (are not ‘parametric volumes’)
I don’t understand well your question: what do you have and what do you want
to obtain?
For a NURBS-surface or line, it is possible to get the parameter vectors
(u,v) and all points (UtilitiesListSurfaces/Lines). In general, a
NURBS-volume can be described in the same way (three parameter vectors
u,v,w and a set of points). These are probably the ‘parametric volumes’.
I thought it would be possible to describe a volume based on these
3D-NURBS in GiD because I need the data of this formulation.
Regards,
Georg
Off course the concept of NURBS could be extended to 3 dimensions (NURBS
volumes),
but GiD don’t use this NURBS volumes of other kind of parametric volumes
trimmed by the boundary surfaces.
We don’t want to have a non-uniform parametrization of the 3D space!!
Our volumes are like our planar surfaces in 2D: defined only by its trimming
boundary, without any parametrization.
If do you need a parametrization you can imagine that your shape is embedded
in the cartesian space, and the x,y,z coordinates are directly an uniform
parametrization.
(imagine and embedding box that could be defined as a NURBS volume with
degree=1 in each direction, and corners as control points, then your u,v,w
will be the x,y,z normalized if you want to be 0,0,0 in one corner and 1,1,1
in the opposite corner)
Define a geometry with NURBS volumes could be interesting also for simple
shapes, topologically equal to a cube, where it could be possible to define
them as untrimmed, but in general this is not possible and the use of a
trimming boundary is necessary.
Note: we are going to use NURBS volumes in future version only as an
auxiliary tool to embed inside some shape and let the user to free-form
deformate the shape by moving control points of this NURBS volume.
Enrique Escolano
----- Original Message -----
From: “Georg Haasemann” georg.haasemann at tu-dresden.de
To: gidlist at gid.cimne.upc.edu
Sent: Monday, June 28, 2010 3:22 PM
Subject: Re: [GiDlist] NURBS volume
Am Montag, den 28.06.2010, 14:28 +0200 schrieb Enrique Escolano:
In GiD volumes are not NURBS volumes, they are defined by a closed
collection of boundary surfaces (are not ‘parametric volumes’)
I don’t understand well your question: what do you have and what do you
want
to obtain?
For a NURBS-surface or line, it is possible to get the parameter vectors
(u,v) and all points (UtilitiesListSurfaces/Lines). In general, a
NURBS-volume can be described in the same way (three parameter vectors
u,v,w and a set of points). These are probably the ‘parametric volumes’.
I thought it would be possible to describe a volume based on these
3D-NURBS in GiD because I need the data of this formulation.
Regards,
Georg
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