# Raytracing of pathline segments (created with TemporalParticlesToPathlines)
**URL:** https://discourse.paraview.org/t/raytracing-of-pathline-segments-created-with-temporalparticlestopathlines/15314
**Category:** ParaView Support
**Created:** [August 27, 2024, 3:12pm UTC](https://discourse.paraview.org/t/raytracing-of-pathline-segments-created-with-temporalparticlestopathlines/15314 "2024-08-27T15:12:28Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@Michael\_Boettinger](https://discourse.paraview.org/u/Michael_Boettinger)
#### Post date: [August 27, 2024, 3:12pm UTC](https://discourse.paraview.org/t/raytracing-of-pathline-segments-created-with-temporalparticlestopathlines/15314/1 "2024-08-27T15:12:28Z")
Hi,
I successfully created an animation of time dependent data using ParticleTracer and TemporalParticlesToPathlines in order to visualize only the most recent 5 time steps of each trajectory. An example for results of this technique (but with other data and settings) can be found here [https://www.youtube.com/watch?v=Rzr5kWRytZY](https://www.youtube.com/watch?v=Rzr5kWRytZY)
Howver, in this case I am interested to see pathline segments that visualize air reaching the coast and flowing over mountains. For a better depth depiction I wanted to use raytracing with enabled shadows.
However, the pathline segments seem to have been computed correctly, but the raytraced version of it looks strange - in some cases it looks like severel tube segments were incorrectly sticked into each other.
Here a much simplified version without shadows of only pathline segments rendered with surface shading and lines rendered as tubes:
And this is the raytraced version - with much smaller line width:
Here a tar file that should include the state files and the pathline segments for one time step as pvd:
[Pathline\_segments.tar](https://discourse.paraview.org/uploads/short-url/qem8chbweXbOPY7gEK8keI8ypEj.tar) (656.5 KB)
I tried Paraview 5.12.1 on RedHat and on Win11.
Cheers,
MIchael
---
### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [August 28, 2024, 7:21am UTC](https://discourse.paraview.org/t/raytracing-of-pathline-segments-created-with-temporalparticlestopathlines/15314/2 "2024-08-28T07:21:14Z")
I confirm there is an issue with ospray rendering in ParaView with lines that are “small”:
Right is OpenGL, left is ospray
Using a polydata with 5 points and a single polyline:
[fail\_ospray.vtu](https://discourse.paraview.org/uploads/short-url/n9i72wYPKvgcN7cAcFTpRiSfvbm.vtu) (1.8 KB)
The bounding box of this dataset is small and this is causing the issue:
Using a Transform filter with a scall 1000\*3 is a possible workaround.
@Michael_Boettinger Could you try the workaround and open the issue here: [https://gitlab.kitware.com/paraview/paraview/-/issues](https://gitlab.kitware.com/paraview/paraview/-/issues)
Thanks!
---
### Author:  [@Michael\_Boettinger](https://discourse.paraview.org/u/Michael_Boettinger)
#### Post date: [August 28, 2024, 9:30am UTC](https://discourse.paraview.org/t/raytracing-of-pathline-segments-created-with-temporalparticlestopathlines/15314/3 "2024-08-28T09:30:01Z")
Thanks Mathieu,
the workaround solves the problem. Of course I had to readjust the camera paths, but the results look good so far!
Cheers,
Michael
---
### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [August 28, 2024, 11:27am UTC](https://discourse.paraview.org/t/raytracing-of-pathline-segments-created-with-temporalparticlestopathlines/15314/4 "2024-08-28T11:27:25Z")
Issue is here: [https://gitlab.kitware.com/paraview/paraview/-/issues/22741](https://gitlab.kitware.com/paraview/paraview/-/issues/22741)