# About Stream Tracer With Custom Source and Particle Tracer Filters
**URL:** https://discourse.paraview.org/t/about-stream-tracer-with-custom-source-and-particle-tracer-filters/16912
**Category:** ParaView Support
**Tags:** python, vtk
**Created:** [July 9, 2025, 6:16am UTC](https://discourse.paraview.org/t/about-stream-tracer-with-custom-source-and-particle-tracer-filters/16912 "2025-07-09T06:16:58Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@Oracle\_0](https://discourse.paraview.org/u/Oracle_0)
#### Post date: [July 9, 2025, 6:16am UTC](https://discourse.paraview.org/t/about-stream-tracer-with-custom-source-and-particle-tracer-filters/16912/1 "2025-07-09T06:16:58Z")
Hi,
How do I set parameters such as Step-Size and Integrator-type for these filters? I can’t see any option in the properties panel.
---
### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [July 9, 2025, 7:15am UTC](https://discourse.paraview.org/t/about-stream-tracer-with-custom-source-and-particle-tracer-filters/16912/2 "2025-07-09T07:15:46Z")
> [@I can't find an option/parameter/control in a dialog, or tab (such as the Properties tab)](https://discourse.paraview.org/t/i-cant-find-an-option-parameter-control-in-a-dialog-or-tab-such-as-the-properties-tab/4512):
>
> Make sure to enable the advanced option by clicking on the gear icon: [2020-05-24-111301\_31x30\_scrot]
---
### Author:  [@Oracle\_0](https://discourse.paraview.org/u/Oracle_0)
#### Post date: [July 9, 2025, 8:32am UTC](https://discourse.paraview.org/t/about-stream-tracer-with-custom-source-and-particle-tracer-filters/16912/3 "2025-07-09T08:32:18Z")
I tried doing it. Unfortunately, I can’t see where I can set Integrator-type like RK2 or RK4 and Step-Size. I have uploaded screenshots.
---
### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [July 9, 2025, 12:02pm UTC](https://discourse.paraview.org/t/about-stream-tracer-with-custom-source-and-particle-tracer-filters/16912/4 "2025-07-09T12:02:54Z")
This is the ParticleTracer whic does not have these parameters exposed.
The StreamTracerWithCustomSource have them.
---
### Author:  [@Oracle\_0](https://discourse.paraview.org/u/Oracle_0)
#### Post date: [July 10, 2025, 7:35am UTC](https://discourse.paraview.org/t/about-stream-tracer-with-custom-source-and-particle-tracer-filters/16912/5 "2025-07-10T07:35:06Z")
Oh, okay. Is there a way to set those parameters for ParticleTracer?
Also, what are default values of those parameters? Like is integrator RK2 or RK4?
---
### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [July 10, 2025, 7:53am UTC](https://discourse.paraview.org/t/about-stream-tracer-with-custom-source-and-particle-tracer-filters/16912/6 "2025-07-10T07:53:58Z")
> [@Oracle\_0](#):
>
> Is there a way to set those parameters for ParticleTracer?
IntegratorType can be exposed with a custom XML plugin.
StepSize doesnt seems to be exposable, there is not C++ API for it as far as I can see.
> what are default values of those parameters? Like is integrator RK2 or RK4?
RK4 is the default
IntegrationStep is 0.5
By the way these should be fixed in VTK/ParaView source code, it pretty simple to add there.