wall attribute command

Syntax

wall attribute <facet> <vertex> keyword ... <range>

Set the value of wall attributes. This command is a synonym for the wall initialize command. Individual attributes can be listed with the wall list command and all attributes can be visualized. The optional vertex keyword can be used to with the velocity, velocity-x, velocity-y, or velocity-z keywords to set the vertex velocities for vertices in the specified range. The optional facet keyword can be used with the conveyor, conveyor-x, conveyor-y, or conveyor-z keywords to set the facet conveyor velocities for facets in the specified range.

cutoff-angle f [wlmodblock]

Set the cutoff angle (an angle in degrees) for walls. By default, the cutoff angle is 0. This angle controls contact state information propagation.

displacement v [wlmodblock]

Accumulated wall displacement vector as a result of cycling.

displacement-x f [wlmodblock]

The \(x\)-component of the accumulated wall displacement as a result of cycling.

displacement-y f [wlmodblock]

The \(y\)-component of the accumulated wall displacement as a result of cycling.

displacement-z f (3D ONLY) [wlmodblock]

The \(z\)-component of the accumulated wall displacement as a result of cycling.

euler v (3D ONLY) [wlmodblock]

Current orientation of Euler angles following the X,Y,Z convention (e.g., rotation about the \(x\)-axis followed by rotation about the y’-axis followed by rotation about the z’‘-axis) in degrees. The orientation is updated only when orientation tracking has been enabled (see model orientation-tracking command). When active, the current clump orientation can be visualized.

euler-x f (3D ONLY) [wlmodblock]

The \(x\)-euler angle (in degrees) of the current wall orientation. See the euler keyword for further details.

euler-y f (3D ONLY) [wlmodblock]

The \(y\)-euler angle (in degrees) of the current wall orientation. See the euler keyword for further details.

euler-z f (3D ONLY) [wlmodblock]

The \(z\)-euler angle (in degrees) of the current wall orientation. See the euler keyword for further details.

fragment i

Fragment ID (see “Fragment”).

position v [wlmodblock]

Wall location vector. This corresponds to the average position of all vertices. The center of rotation is not modified.

position-x f [wlmodblock]

The \(x\)-component of the wall location. This corresponds to the average position of all vertices. The center of rotation is not modified.

position-y f [wlmodblock]

The \(y\)-component of the wall location. This corresponds to the average position of all vertices. The center of rotation is not modified.

position-z f [wlmodblock]

The \(z\)-component of the wall location. This corresponds to the average position of all vertices. The center of rotation is not modified.

rotation-center v [wlmodblock]

Set the center of rotation for walls in the range. This is the position about which rotations occur when an angular velocity is supplied to a wall. The center of rotation translates with the wall if a translational velocity is supplied. The default center of rotation is the origin.

rotation-center-x f [wlmodblock]

Set the \(x\)-component of the center of rotation for walls in the range. This is the position about which rotations occur when an angular velocity is supplied to a wall. The center of rotation translates with the wall if a translational velocity is supplied. The default center of rotation is the origin.

rotation-center-y f [wlmodblock]

Set the \(y\)-component of the center of rotation for walls in the range. This is the position about which rotations occur when an angular velocity is supplied to a wall. The center of rotation translates with the wall if a translational velocity is supplied. The default center of rotation is the origin.

rotation-center-z f (3D ONLY) [wlmodblock]

Set the \(z\)-component of the center of rotation for walls in the range. This is the position about which rotations occur when an angular velocity is supplied to a wall. The center of rotation translates with the wall if a translational velocity is supplied. The default center of rotation is the origin.

spin fx fy fz (y- and z- components are 3D ONLY) [wlmodblock]

The wall angular velocity in radians per second. Walls rotate around their center of rotation.

spin-x f (3D ONLY) [wlmodblock]

The \(x\)-component of the wall angular velocity in radians per second. Walls rotate around their center of rotation.

spin-y f (3D ONLY) [wlmodblock]

The \(y\)-component of the wall angular velocity in radians per second. Walls rotate around their center of rotation.

spin-z f (3D ONLY) [wlmodblock]

The \(z\)-component of the wall angular velocity in radians per second. Walls rotate around their center of rotation.

velocity v [wlmodblock]

Wall translational velocity vector. If given with the vertex keyword, then this corresponds to the vertex velocity and the range applies to vertices.

velocity-x f [wlmodblock]

The \(x\)-component of the wall translational velocity. If given with the vertex keyword, then this corresponds to the \(x\)-component of the vertex velocity and the range applies to vertices.

velocity-y f [wlmodblock]

The \(y\)-component of the wall translational velocity. If given with the vertex keyword, then this corresponds to the \(y\)-component of the vertex velocity and the range applies to vertices.

velocity-z f (3D ONLY) [wlmodblock]

The \(z\)-component of the wall translational velocity. If given with the vertex keyword, then this corresponds to the \(z\)-component of the vertex velocity and the range applies to vertices.

velocity-conveyor v [wlmodblock]

Set the facet conveyor velocity vector. If given with the facet keyword, then the range applies to facets. Otherwise the conveyor velocity is set for all facets in each wall in the specified range. The conveyor velocity is a fictitious velocity that is added to the wall velocity when calculating the relative velocity between a facet and another piece. A conveyor velocity cannot be active when vertex velocities are active. Setting a nonzero conveyor velocity allows one to simulate conveyance of balls or clumps along facets without moving the facets.

velocity-conveyor-x f [wlmodblock]

Set the \(x\)-component of the facet conveyor velocity. If given with the facet keyword, then the range applies to facets. Otherwise the conveyor velocity is set for all facets in each wall in the specified range. The conveyor velocity is a fictitious velocity that is added to the wall velocity when calculating the relative velocity between a facet and another piece. A conveyor velocity cannot be active when vertex velocities are active. Setting a nonzero conveyor velocity allows one to simulate conveyance of balls or clumps along facets without moving the facets.

velocity-conveyor-y f [wlmodblock]

Set the \(y\)-component of the facet conveyor velocity. If given with the facet keyword, then the range applies to facets. Otherwise the conveyor velocity is set for all facets in each wall in the specified range. The conveyor velocity is a fictitious velocity that is added to the wall velocity when calculating the relative velocity between a facet and another piece. A conveyor velocity cannot be active when vertex velocities are active. Setting a nonzero conveyor velocity allows one to simulate conveyance of balls or clumps along facets without moving the facets.

velocity-conveyor-z f (3D ONLY) [wlmodblock]

Set the \(z\)-component of the facet conveyor velocity. If given with the facet keyword, then the range applies to facets. Otherwise the conveyor velocity is set for all facets in each wall in the specified range. The conveyor velocity is a fictitious velocity that is added to the wall velocity when calculating the relative velocity between a facet and another piece. A conveyor velocity cannot be active when vertex velocities are active. Setting a nonzero conveyor velocity allows one to simulate conveyance of balls or clumps along facets without moving the facets.

wall attribute Keyword Block

The following keywords may be used to modify the base value supplied. cutoff-angle, displacement, displacement-x, displacement-y, displacement-z, euler, euler-x, euler-y, euler-z, position, position-x, position-y, position-z, rotation-center, rotation-center-x, rotation-center-y, rotation-center-z, spin, spin-x, spin-y, spin-z, velocity, velocity-conveyor, velocity-conveyor-x, velocity-conveyor-y, velocity-conveyor-z, velocity-x, velocity-y and velocity-z.

add f

Add f to the existing value.

gradient v

Apply a linear gradient in each of the axes directions starting at the origin.

gradient-x f

Apply a linear gradient in the \(x\)-direction starting at the origin.

gradient-y f

Apply a linear gradient in the \(y\)-direction starting at the origin.

gradient-z f (3D ONLY)

Apply a linear gradient in the \(z\)-direction starting at the origin.

multiply f

Multiply the existing value by f.

replace f

Replace the existing value with f.

Note

Be aware of the distinction between attributes and properties! The tutorial example “Attributes and Properties” discusses this issue in detail.

Usage Examples

Set the \(z\)-component of velocity for the wall named platenBottom.

wall attribute velocity-z [platenVel] range name 'platenBottom'

from “SleevedTriaxialTest.dat” in Sleeved Triaxial Test of a Bonded Material

Set the \(z\)-component of velocity for the wall with ID 100.

wall attribute velocity-z 0.0 range id 100 by wall

from “move_container.dat” in Rolling Resistance Linear Contact Model: Repose Angle

Set the center of rotation for walls in group wallassembly.

wall attribute rotation-center [rp_] range group 'wallassembly'

from “BlenderBalls.dat” in Ribbon Blender