# 3.8.16: User Iso-Lines and Stream-Lines

![Fig.3.8.16.1: User defined Iso-lines (red) and stream-lines (green) on a rectangular shell patch](https://1646753513-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-M9XteyGDAU3Odla53cC%2Fsync%2Ffefcc770017c5ade8c1e29088aec38d6245ae2bf.png?generation=1591871202189786\&alt=media)

{% hint style="info" %}
The definition “User\_Iso\_Lines.gh” can be found in the Karamba3D installation folder under “..- Examples/TestExamples/”. Double-click on the Karamba3D desktop icon to get there.
{% endhint %}

Both components **“User Iso-Lines”** and **“User Stream Lines”** work similar to the **“IsoLines”**- (see section [3.6.12](https://manual-1-3.karamba3d.com/3.6-results/3.6.12-line-results-on-shells#isolines-on-shells)) and **“Principal Stress Lines on Shells”**-components (see section [3.6.12](https://manual-1-3.karamba3d.com/3.6-results/3.6.12-line-results-on-shells#principal-stress-lines-on-shells)) respectively. The only difference lies in the fact that for each node of the model (which includes also nodes that only connect to beams) a value (input-plug **“Vals”**) or vector (input-plug **“TVecs”**) tangent to the flow needs to be supplied.