create streamlines and stream ribbons for a Multi_Block object
module DVstream_multi_block {
/* integrates velocity field (produces streamlines) */
Multi_Block+Iparam &in { /* input field */
nblocks+req;
};
Grid+Xform+Iparam &probe { /* where the streamlines originate */
nnodes+req;
coordinates+req;
coordinates.values+req;
};
int+Iparam order; /* order of integration */
int+Iparam forw_back; /* toggle to generate lines forward */
int+Iparam nseg;
float+Iparam min_vel;
int+Iparam max_seg;
int+Iparam stream_comp;
int+Iparam ribbons;
float+notify rib_width;
float+notify rib_angle;
Mesh+Node_Data+Oparam out;
method+notify_val+notify_inst stream_multi_block<status=1> =
"DVstream_multi_block";
};
DVstream_multi_block creates streamlines and stream ribbons for a Multi_Block object.
Multi_Block. The input multiblock data set.
Grid+Xform. Streamlines start at each node of this mesh.
int. Integration order for the streamline advection. Higher orders are more accurate but execute more slowly. The default is 2, for second-order integration. The range is from 1 to 4.
int. When on (nonzero), streamlines are advected forward, in the downstream direction of the flow. When off (zero), they are advected backward, upstream in the flow. The default is forward.
int. How many integration steps are used per grid cell to compute the streamline path. The default is 2.
float. If the absolute value of the velocity is less than this limit, the streamline advection is terminated. This is usually used to avoid wasting computation on streamlines which are barely moving. Velocity is measured in the coordinate system of the data set. The default is 0.000001.
int. Maximum number of integration steps to take for an individual streamline. A streamline is terminated either when it leaves the data set, when the absolute value of its velocity is less than min_velocity (see below), or when it exceeds this number of integration steps.
int. Which component of the data set to use.
int. When on (nonzero), produces stream ribbons rather than streamlines. The width of the ribbons varies along the length with the divergence of the field, and the angle varies with the curl.
float. This value scales the width of the ribbons when ribbons are turned on.
float. This value sets the initial angle at which the ribbons are drawn. The ribbons twist along their length according to the curl of the field.
Mesh+Node_Data. Field containing the streamlines.