In my application I need to generate a surface mesh which represents the solid
boundaries in an assembly composed of several parts (imported as ACIS files).
The contact surfaces (the interface between adjiacient solids) must generate
a common mesh and the mesh file should include the information on the solids
connectivity. Furthermore I need to have a mesh that is composed of cubic
elements (10 points triangles).
Is it a way to get all this data structure using the GiD software ?
Thanks
Walter Steffe
[GiDlist] cubic surface mesh
Moderator: GiD Team
[GiDlist] cubic surface mesh
As I underestand, you don't need volume elements (tetrahedrals or
hexahedrals), you only need the surface mesh (triangles)
But in other hand, you said that "should include the information on the
solids connectivity" ??
If you need to have both: volume, and surface elements, can force the
surfaces to create elements with
(menu: Mesh-Mesh criteria-Mesh-Surfaces, and select the surfaces)
(by default, when are generated the volume elements, the surface elements
are removed)
If you need a common mesh between parts, you must collapse the common
surfaces in order to have a single surface (shared between volumes if you
need also volume mesh).
If you need a different copy of nodes on each body, maybe you need to create
a GiD "Contact volume" between two surfaces, in order to force to have a
similar mesh in this two surfaces. (menu: Geometry-Create-Contact volume)
About the cubic elements, GiD only can manage linear or quadratic ones.(see
menu: Mesh-Quadratic elements),
Maybe you can write linear elements with GiD, and increase the degree to
cubic inserting nodes inside your own code.
Regards
Enrique Escolano
----- Original Message -----
From: "walter steffè" walter.steffe at aleniaspazio.it
To: gidlist at gatxan.cimne.upc.es
Sent: Friday, December 09, 2005 9:52 AM
Subject: [GiDlist] cubic surface mesh
In my application I need to generate a surface mesh which represents the
solid
boundaries in an assembly composed of several parts (imported as ACIS
files).
The contact surfaces (the interface between adjiacient solids) must
generate
a common mesh and the mesh file should include the information on the
solids
connectivity. Furthermore I need to have a mesh that is composed of cubic
elements (10 points triangles).
Is it a way to get all this data structure using the GiD software ?
Thanks
Walter Steffe
_______________________________________________
GiDlist mailing list
GiDlist at gid.cimne.upc.es
http://gid.cimne.upc.es/mailman/listinfo/gidlist
hexahedrals), you only need the surface mesh (triangles)
But in other hand, you said that "should include the information on the
solids connectivity" ??
If you need to have both: volume, and surface elements, can force the
surfaces to create elements with
(menu: Mesh-Mesh criteria-Mesh-Surfaces, and select the surfaces)
(by default, when are generated the volume elements, the surface elements
are removed)
If you need a common mesh between parts, you must collapse the common
surfaces in order to have a single surface (shared between volumes if you
need also volume mesh).
If you need a different copy of nodes on each body, maybe you need to create
a GiD "Contact volume" between two surfaces, in order to force to have a
similar mesh in this two surfaces. (menu: Geometry-Create-Contact volume)
About the cubic elements, GiD only can manage linear or quadratic ones.(see
menu: Mesh-Quadratic elements),
Maybe you can write linear elements with GiD, and increase the degree to
cubic inserting nodes inside your own code.
Regards
Enrique Escolano
----- Original Message -----
From: "walter steffè" walter.steffe at aleniaspazio.it
To: gidlist at gatxan.cimne.upc.es
Sent: Friday, December 09, 2005 9:52 AM
Subject: [GiDlist] cubic surface mesh
In my application I need to generate a surface mesh which represents the
solid
boundaries in an assembly composed of several parts (imported as ACIS
files).
The contact surfaces (the interface between adjiacient solids) must
generate
a common mesh and the mesh file should include the information on the
solids
connectivity. Furthermore I need to have a mesh that is composed of cubic
elements (10 points triangles).
Is it a way to get all this data structure using the GiD software ?
Thanks
Walter Steffe
_______________________________________________
GiDlist mailing list
GiDlist at gid.cimne.upc.es
http://gid.cimne.upc.es/mailman/listinfo/gidlist
-
walter steffè
[GiDlist] cubic surface mesh
Hello Enrique
Thanks for your reply
On Friday 09 December 2005 12:27, Enrique Escolano wrote:
As I underestand, you don't need volume elements (tetrahedrals or
hexahedrals), you only need the surface mesh (triangles)
But in other hand, you said that "should include the information on the
solids connectivity" ??
When I speak of volume connectivity I just want to say that the surface mesh
elements which belong to a common face (a face shared between two solids)
should include e reference to both adjiacient solids, that is to the
geometrical parts of the CAD assembly (and not to the volume elements which
are not needed).
If you need a common mesh between parts, you must collapse the common
surfaces in order to have a single surface (shared between volumes if you
need also volume mesh).
Yes this is the case (I need a common mesh between parts).
Is it possible to collapse all the common surfaces in an automatic way ?
What happens when the adjiacient faces are not equal? In this case only the
common part (that is the intersection of the two tangent surfaces) should be
collapsed. I would like to have something that can run in batch mode and that
is able to perform the surface collapsing and the surface meshing without any
human intervention.
About the cubic elements, GiD only can manage linear or quadratic ones.(see
menu: Mesh-Quadratic elements),
Maybe you can write linear elements with GiD, and increase the degree to
cubic inserting nodes inside your own code.
Ok this could be a solution but it is necessary to move the inner points from
the triangle plane to the curved surface. This could be done trough the
intersection of the surface with the triangle normal but I think that this
operation could be very time consuminig.
If the mesher works in the parametric space of the surface it is much more
efficient to use the surface mapping (u,v x,y,z) but, from the GiD manual,
I can not see any command which exposes this mapping.
Regards
Walter Steffe
Regards
Enrique Escolano
----- Original Message -----
From: "walter steffè" walter.steffe at aleniaspazio.it
To: gidlist at gatxan.cimne.upc.es
Sent: Friday, December 09, 2005 9:52 AM
Subject: [GiDlist] cubic surface mesh
In my application I need to generate a surface mesh which represents the
solid
boundaries in an assembly composed of several parts (imported as ACIS
files).
The contact surfaces (the interface between adjiacient solids) must
generate
a common mesh and the mesh file should include the information on the
solids
connectivity. Furthermore I need to have a mesh that is composed of cubic
elements (10 points triangles).
Is it a way to get all this data structure using the GiD software ?
Thanks
Walter Steffe
_______________________________________________
GiDlist mailing list
GiDlist at gid.cimne.upc.es
http://gid.cimne.upc.es/mailman/listinfo/gidlist
_______________________________________________
GiDlist mailing list
GiDlist at gid.cimne.upc.es
http://gid.cimne.upc.es/mailman/listinfo/gidlist
Thanks for your reply
On Friday 09 December 2005 12:27, Enrique Escolano wrote:
As I underestand, you don't need volume elements (tetrahedrals or
hexahedrals), you only need the surface mesh (triangles)
But in other hand, you said that "should include the information on the
solids connectivity" ??
When I speak of volume connectivity I just want to say that the surface mesh
elements which belong to a common face (a face shared between two solids)
should include e reference to both adjiacient solids, that is to the
geometrical parts of the CAD assembly (and not to the volume elements which
are not needed).
If you need a common mesh between parts, you must collapse the common
surfaces in order to have a single surface (shared between volumes if you
need also volume mesh).
Yes this is the case (I need a common mesh between parts).
Is it possible to collapse all the common surfaces in an automatic way ?
What happens when the adjiacient faces are not equal? In this case only the
common part (that is the intersection of the two tangent surfaces) should be
collapsed. I would like to have something that can run in batch mode and that
is able to perform the surface collapsing and the surface meshing without any
human intervention.
About the cubic elements, GiD only can manage linear or quadratic ones.(see
menu: Mesh-Quadratic elements),
Maybe you can write linear elements with GiD, and increase the degree to
cubic inserting nodes inside your own code.
Ok this could be a solution but it is necessary to move the inner points from
the triangle plane to the curved surface. This could be done trough the
intersection of the surface with the triangle normal but I think that this
operation could be very time consuminig.
If the mesher works in the parametric space of the surface it is much more
efficient to use the surface mapping (u,v x,y,z) but, from the GiD manual,
I can not see any command which exposes this mapping.
Regards
Walter Steffe
Regards
Enrique Escolano
----- Original Message -----
From: "walter steffè" walter.steffe at aleniaspazio.it
To: gidlist at gatxan.cimne.upc.es
Sent: Friday, December 09, 2005 9:52 AM
Subject: [GiDlist] cubic surface mesh
In my application I need to generate a surface mesh which represents the
solid
boundaries in an assembly composed of several parts (imported as ACIS
files).
The contact surfaces (the interface between adjiacient solids) must
generate
a common mesh and the mesh file should include the information on the
solids
connectivity. Furthermore I need to have a mesh that is composed of cubic
elements (10 points triangles).
Is it a way to get all this data structure using the GiD software ?
Thanks
Walter Steffe
_______________________________________________
GiDlist mailing list
GiDlist at gid.cimne.upc.es
http://gid.cimne.upc.es/mailman/listinfo/gidlist
_______________________________________________
GiDlist mailing list
GiDlist at gid.cimne.upc.es
http://gid.cimne.upc.es/mailman/listinfo/gidlist
-
Malte Neumann
[GiDlist] Nurbs surface
Hello,
I would like to create new points/nodes in my calculation software on a
Nurbs surface created in GiD. Can you give me a hint how to calculate
points on the surface. Are there any functions from GiD I could use??
Thanks for any hints
Malte
--
Malte Neumann
Institute of Structural Mechanics, University of Stuttgart, Germany
http://www.uni-stuttgart.de/ibs/members/neumann/
I would like to create new points/nodes in my calculation software on a
Nurbs surface created in GiD. Can you give me a hint how to calculate
points on the surface. Are there any functions from GiD I could use??
Thanks for any hints
Malte
--
Malte Neumann
Institute of Structural Mechanics, University of Stuttgart, Germany
http://www.uni-stuttgart.de/ibs/members/neumann/
-
Malte Neumann
[GiDlist] Nurbsurface control points
Hi,
I am a little confused about the number of control points for the two
directions of nurbsurfaces. This is the data of a nurbsurface:
NURBSURFACE
Num: 15 HigherEntity: 1 conditions: 2 material: 0
LAYER: fluid
Meshing Info: (num=55,NOE=56) Elemtype=3 IsStructured=1 Meshing=Default size=0
NumLines: 4
Line: 6 Orientation: DIFF1ST
Line: 42 Orientation: SAME1ST
Line: 30 Orientation: SAME1ST
Line: 41 Orientation: DIFF1ST
Number of Control Points= 3 2 Degree= 2 1
Point 1,1 coords:0.222740,0.222740,0.000000
Point 1,2 coords:0.445473,-0.000000,0.000000
Point 1,3 coords:0.222740,-0.222740,0.000000
Point 2,1 coords:0.222740,0.222740,3.000000
Point 2,2 coords:0.445473,-0.000000,3.000000
Point 2,3 coords:0.222740,-0.222740,3.000000
Number of knots in U= 6
knot 1 value=0.000000
knot 2 value=0.000000
knot 3 value=0.000000
knot 4 value=1.000000
knot 5 value=1.000000
knot 6 value=1.000000
Number of knots in V= 4
knot 1 value=0.000000
knot 2 value=0.000000
knot 3 value=1.000000
knot 4 value=1.000000
Rational weights:
1.000000
0.707117
1.000000
1.000000
0.707117
1.000000
IsTrimmed: 0
Center: 0.315000 -0.000000 1.500000
Normal: -1.000000 0.000000 0.000000
END NURBSURFACE
There are two directions for the surface U and V.
In V direction there are 3 points, 6 knots and the degree is 3
In U direction there are 2 points, 4 knots and the degree is 2
The points (mark by the x) should be located like that:
---- U
| |--------------------------|
| | |
| | x x x |
V V | 1,1 2,1 3,1 |
| |
| x x x |
| 1,2 2,2 3,2 |
| |
|--------------------------|
Using this scheme I do not understand the list of coordinates printed by
GiD: it looks like two points in the first (U) direction and three points
in the second (V) direction.
Could you please explain the GiD output.
Thanks a lot for your help.
Malte
--
Malte Neumann
Institute of Structural Mechanics, University of Stuttgart, Germany
http://www.uni-stuttgart.de/ibs/members/neumann/
I am a little confused about the number of control points for the two
directions of nurbsurfaces. This is the data of a nurbsurface:
NURBSURFACE
Num: 15 HigherEntity: 1 conditions: 2 material: 0
LAYER: fluid
Meshing Info: (num=55,NOE=56) Elemtype=3 IsStructured=1 Meshing=Default size=0
NumLines: 4
Line: 6 Orientation: DIFF1ST
Line: 42 Orientation: SAME1ST
Line: 30 Orientation: SAME1ST
Line: 41 Orientation: DIFF1ST
Number of Control Points= 3 2 Degree= 2 1
Point 1,1 coords:0.222740,0.222740,0.000000
Point 1,2 coords:0.445473,-0.000000,0.000000
Point 1,3 coords:0.222740,-0.222740,0.000000
Point 2,1 coords:0.222740,0.222740,3.000000
Point 2,2 coords:0.445473,-0.000000,3.000000
Point 2,3 coords:0.222740,-0.222740,3.000000
Number of knots in U= 6
knot 1 value=0.000000
knot 2 value=0.000000
knot 3 value=0.000000
knot 4 value=1.000000
knot 5 value=1.000000
knot 6 value=1.000000
Number of knots in V= 4
knot 1 value=0.000000
knot 2 value=0.000000
knot 3 value=1.000000
knot 4 value=1.000000
Rational weights:
1.000000
0.707117
1.000000
1.000000
0.707117
1.000000
IsTrimmed: 0
Center: 0.315000 -0.000000 1.500000
Normal: -1.000000 0.000000 0.000000
END NURBSURFACE
There are two directions for the surface U and V.
In V direction there are 3 points, 6 knots and the degree is 3
In U direction there are 2 points, 4 knots and the degree is 2
The points (mark by the x) should be located like that:
---- U
| |--------------------------|
| | |
| | x x x |
V V | 1,1 2,1 3,1 |
| |
| x x x |
| 1,2 2,2 3,2 |
| |
|--------------------------|
Using this scheme I do not understand the list of coordinates printed by
GiD: it looks like two points in the first (U) direction and three points
in the second (V) direction.
Could you please explain the GiD output.
Thanks a lot for your help.
Malte
--
Malte Neumann
Institute of Structural Mechanics, University of Stuttgart, Germany
http://www.uni-stuttgart.de/ibs/members/neumann/
[GiDlist] Nurbsurface control points
The control points are like you said: and array of 3x2 points in u,v
directions
The u,v degrees are 2 and 1, not 3 an 2 (maybe you speak about the
order=degree+1)
Maybe the label "Point i,j" is confusing, because the second index is
related to the u coordinate instead to the v
Notes:
- When you list a NURBS, if you double click on the line that show the
control point, this coordinate will be pointed
- When you use some tools, like divide surface, the u,v coordinate lines
will be temporary drawn.
Regards
Enrique
----- Original Message -----
From: "Malte Neumann" neumann at statik.uni-stuttgart.de
To: "gid user list" gidlist at gatxan.cimne.upc.es
Sent: Tuesday, December 13, 2005 5:45 PM
Subject: [GiDlist] Nurbsurface control points
Hi,
I am a little confused about the number of control points for the two
directions of nurbsurfaces. This is the data of a nurbsurface:
NURBSURFACE
Num: 15 HigherEntity: 1 conditions: 2 material: 0
LAYER: fluid
Meshing Info: (num=55,NOE=56) Elemtype=3 IsStructured=1 Meshing=Default
size=0
NumLines: 4
Line: 6 Orientation: DIFF1ST
Line: 42 Orientation: SAME1ST
Line: 30 Orientation: SAME1ST
Line: 41 Orientation: DIFF1ST
Number of Control Points= 3 2 Degree= 2 1
Point 1,1 coords:0.222740,0.222740,0.000000
Point 1,2 coords:0.445473,-0.000000,0.000000
Point 1,3 coords:0.222740,-0.222740,0.000000
Point 2,1 coords:0.222740,0.222740,3.000000
Point 2,2 coords:0.445473,-0.000000,3.000000
Point 2,3 coords:0.222740,-0.222740,3.000000
Number of knots in U= 6
knot 1 value=0.000000
knot 2 value=0.000000
knot 3 value=0.000000
knot 4 value=1.000000
knot 5 value=1.000000
knot 6 value=1.000000
Number of knots in V= 4
knot 1 value=0.000000
knot 2 value=0.000000
knot 3 value=1.000000
knot 4 value=1.000000
Rational weights:
1.000000
0.707117
1.000000
1.000000
0.707117
1.000000
IsTrimmed: 0
Center: 0.315000 -0.000000 1.500000
Normal: -1.000000 0.000000 0.000000
END NURBSURFACE
There are two directions for the surface U and V.
In V direction there are 3 points, 6 knots and the degree is 3
In U direction there are 2 points, 4 knots and the degree is 2
The points (mark by the x) should be located like that:
---- U
| |--------------------------|
| | |
| | x x x |
V V | 1,1 2,1 3,1 |
| |
| x x x |
| 1,2 2,2 3,2 |
| |
|--------------------------|
Using this scheme I do not understand the list of coordinates printed by
GiD: it looks like two points in the first (U) direction and three points
in the second (V) direction.
Could you please explain the GiD output.
Thanks a lot for your help.
Malte
--
Malte Neumann
Institute of Structural Mechanics, University of Stuttgart, Germany
http://www.uni-stuttgart.de/ibs/members/neumann/
_______________________________________________
GiDlist mailing list
GiDlist at gid.cimne.upc.es
http://gid.cimne.upc.es/mailman/listinfo/gidlist
directions
The u,v degrees are 2 and 1, not 3 an 2 (maybe you speak about the
order=degree+1)
Maybe the label "Point i,j" is confusing, because the second index is
related to the u coordinate instead to the v
Notes:
- When you list a NURBS, if you double click on the line that show the
control point, this coordinate will be pointed
- When you use some tools, like divide surface, the u,v coordinate lines
will be temporary drawn.
Regards
Enrique
----- Original Message -----
From: "Malte Neumann" neumann at statik.uni-stuttgart.de
To: "gid user list" gidlist at gatxan.cimne.upc.es
Sent: Tuesday, December 13, 2005 5:45 PM
Subject: [GiDlist] Nurbsurface control points
Hi,
I am a little confused about the number of control points for the two
directions of nurbsurfaces. This is the data of a nurbsurface:
NURBSURFACE
Num: 15 HigherEntity: 1 conditions: 2 material: 0
LAYER: fluid
Meshing Info: (num=55,NOE=56) Elemtype=3 IsStructured=1 Meshing=Default
size=0
NumLines: 4
Line: 6 Orientation: DIFF1ST
Line: 42 Orientation: SAME1ST
Line: 30 Orientation: SAME1ST
Line: 41 Orientation: DIFF1ST
Number of Control Points= 3 2 Degree= 2 1
Point 1,1 coords:0.222740,0.222740,0.000000
Point 1,2 coords:0.445473,-0.000000,0.000000
Point 1,3 coords:0.222740,-0.222740,0.000000
Point 2,1 coords:0.222740,0.222740,3.000000
Point 2,2 coords:0.445473,-0.000000,3.000000
Point 2,3 coords:0.222740,-0.222740,3.000000
Number of knots in U= 6
knot 1 value=0.000000
knot 2 value=0.000000
knot 3 value=0.000000
knot 4 value=1.000000
knot 5 value=1.000000
knot 6 value=1.000000
Number of knots in V= 4
knot 1 value=0.000000
knot 2 value=0.000000
knot 3 value=1.000000
knot 4 value=1.000000
Rational weights:
1.000000
0.707117
1.000000
1.000000
0.707117
1.000000
IsTrimmed: 0
Center: 0.315000 -0.000000 1.500000
Normal: -1.000000 0.000000 0.000000
END NURBSURFACE
There are two directions for the surface U and V.
In V direction there are 3 points, 6 knots and the degree is 3
In U direction there are 2 points, 4 knots and the degree is 2
The points (mark by the x) should be located like that:
---- U
| |--------------------------|
| | |
| | x x x |
V V | 1,1 2,1 3,1 |
| |
| x x x |
| 1,2 2,2 3,2 |
| |
|--------------------------|
Using this scheme I do not understand the list of coordinates printed by
GiD: it looks like two points in the first (U) direction and three points
in the second (V) direction.
Could you please explain the GiD output.
Thanks a lot for your help.
Malte
--
Malte Neumann
Institute of Structural Mechanics, University of Stuttgart, Germany
http://www.uni-stuttgart.de/ibs/members/neumann/
_______________________________________________
GiDlist mailing list
GiDlist at gid.cimne.upc.es
http://gid.cimne.upc.es/mailman/listinfo/gidlist
-
Malte Neumann
[GiDlist] Nurbsurface control points
On Tue, Dec 13, 2005 at 08:17:28PM +0100, Enrique Escolano wrote:
The control points are like you said: and array of 3x2 points in u,v
directions
The u,v degrees are 2 and 1, not 3 an 2 (maybe you speak about the
order=degree+1)
Sorry, this was just a typing error.
Maybe the label "Point i,j" is confusing, because the second index is
related to the u coordinate instead to the v
Ok, that is important to know. I hope that the weights are in the same
order: second index = U running fastest, i.e.
1,1
1,2
1,3
2,1
2,2
2,3
Thanks a lot for your advice.
Malte
Notes:
- When you list a NURBS, if you double click on the line that show the
control point, this coordinate will be pointed
- When you use some tools, like divide surface, the u,v coordinate lines
will be temporary drawn.
Regards
Enrique
----- Original Message -----
From: "Malte Neumann" neumann at statik.uni-stuttgart.de
To: "gid user list" gidlist at gatxan.cimne.upc.es
Sent: Tuesday, December 13, 2005 5:45 PM
Subject: [GiDlist] Nurbsurface control points
Hi,
I am a little confused about the number of control points for the two
directions of nurbsurfaces. This is the data of a nurbsurface:
NURBSURFACE
Num: 15 HigherEntity: 1 conditions: 2 material: 0
LAYER: fluid
Meshing Info: (num=55,NOE=56) Elemtype=3 IsStructured=1 Meshing=Default
size=0
NumLines: 4
Line: 6 Orientation: DIFF1ST
Line: 42 Orientation: SAME1ST
Line: 30 Orientation: SAME1ST
Line: 41 Orientation: DIFF1ST
Number of Control Points= 3 2 Degree= 2 1
Point 1,1 coords:0.222740,0.222740,0.000000
Point 1,2 coords:0.445473,-0.000000,0.000000
Point 1,3 coords:0.222740,-0.222740,0.000000
Point 2,1 coords:0.222740,0.222740,3.000000
Point 2,2 coords:0.445473,-0.000000,3.000000
Point 2,3 coords:0.222740,-0.222740,3.000000
Number of knots in U= 6
knot 1 value=0.000000
knot 2 value=0.000000
knot 3 value=0.000000
knot 4 value=1.000000
knot 5 value=1.000000
knot 6 value=1.000000
Number of knots in V= 4
knot 1 value=0.000000
knot 2 value=0.000000
knot 3 value=1.000000
knot 4 value=1.000000
Rational weights:
1.000000
0.707117
1.000000
1.000000
0.707117
1.000000
IsTrimmed: 0
Center: 0.315000 -0.000000 1.500000
Normal: -1.000000 0.000000 0.000000
END NURBSURFACE
There are two directions for the surface U and V.
In V direction there are 3 points, 6 knots and the degree is 3
In U direction there are 2 points, 4 knots and the degree is 2
The points (mark by the x) should be located like that:
---- U
| |--------------------------|
| | |
| | x x x |
V V | 1,1 2,1 3,1 |
| |
| x x x |
| 1,2 2,2 3,2 |
| |
|--------------------------|
Using this scheme I do not understand the list of coordinates printed by
GiD: it looks like two points in the first (U) direction and three points
in the second (V) direction.
Could you please explain the GiD output.
Thanks a lot for your help.
Malte
--
Malte Neumann
Institute of Structural Mechanics, University of Stuttgart, Germany
http://www.uni-stuttgart.de/ibs/members/neumann/
_______________________________________________
GiDlist mailing list
GiDlist at gid.cimne.upc.es
http://gid.cimne.upc.es/mailman/listinfo/gidlist
_______________________________________________
GiDlist mailing list
GiDlist at gid.cimne.upc.es
http://gid.cimne.upc.es/mailman/listinfo/gidlist
--
Malte Neumann
Institute of Structural Mechanics, University of Stuttgart, Germany
http://www.uni-stuttgart.de/ibs/members/neumann/
The control points are like you said: and array of 3x2 points in u,v
directions
The u,v degrees are 2 and 1, not 3 an 2 (maybe you speak about the
order=degree+1)
Sorry, this was just a typing error.
Maybe the label "Point i,j" is confusing, because the second index is
related to the u coordinate instead to the v
Ok, that is important to know. I hope that the weights are in the same
order: second index = U running fastest, i.e.
1,1
1,2
1,3
2,1
2,2
2,3
Thanks a lot for your advice.
Malte
Notes:
- When you list a NURBS, if you double click on the line that show the
control point, this coordinate will be pointed
- When you use some tools, like divide surface, the u,v coordinate lines
will be temporary drawn.
Regards
Enrique
----- Original Message -----
From: "Malte Neumann" neumann at statik.uni-stuttgart.de
To: "gid user list" gidlist at gatxan.cimne.upc.es
Sent: Tuesday, December 13, 2005 5:45 PM
Subject: [GiDlist] Nurbsurface control points
Hi,
I am a little confused about the number of control points for the two
directions of nurbsurfaces. This is the data of a nurbsurface:
NURBSURFACE
Num: 15 HigherEntity: 1 conditions: 2 material: 0
LAYER: fluid
Meshing Info: (num=55,NOE=56) Elemtype=3 IsStructured=1 Meshing=Default
size=0
NumLines: 4
Line: 6 Orientation: DIFF1ST
Line: 42 Orientation: SAME1ST
Line: 30 Orientation: SAME1ST
Line: 41 Orientation: DIFF1ST
Number of Control Points= 3 2 Degree= 2 1
Point 1,1 coords:0.222740,0.222740,0.000000
Point 1,2 coords:0.445473,-0.000000,0.000000
Point 1,3 coords:0.222740,-0.222740,0.000000
Point 2,1 coords:0.222740,0.222740,3.000000
Point 2,2 coords:0.445473,-0.000000,3.000000
Point 2,3 coords:0.222740,-0.222740,3.000000
Number of knots in U= 6
knot 1 value=0.000000
knot 2 value=0.000000
knot 3 value=0.000000
knot 4 value=1.000000
knot 5 value=1.000000
knot 6 value=1.000000
Number of knots in V= 4
knot 1 value=0.000000
knot 2 value=0.000000
knot 3 value=1.000000
knot 4 value=1.000000
Rational weights:
1.000000
0.707117
1.000000
1.000000
0.707117
1.000000
IsTrimmed: 0
Center: 0.315000 -0.000000 1.500000
Normal: -1.000000 0.000000 0.000000
END NURBSURFACE
There are two directions for the surface U and V.
In V direction there are 3 points, 6 knots and the degree is 3
In U direction there are 2 points, 4 knots and the degree is 2
The points (mark by the x) should be located like that:
---- U
| |--------------------------|
| | |
| | x x x |
V V | 1,1 2,1 3,1 |
| |
| x x x |
| 1,2 2,2 3,2 |
| |
|--------------------------|
Using this scheme I do not understand the list of coordinates printed by
GiD: it looks like two points in the first (U) direction and three points
in the second (V) direction.
Could you please explain the GiD output.
Thanks a lot for your help.
Malte
--
Malte Neumann
Institute of Structural Mechanics, University of Stuttgart, Germany
http://www.uni-stuttgart.de/ibs/members/neumann/
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--
Malte Neumann
Institute of Structural Mechanics, University of Stuttgart, Germany
http://www.uni-stuttgart.de/ibs/members/neumann/