# Catalyst script not rendering the requested contour

**URL:** https://discourse.paraview.org/t/catalyst-script-not-rendering-the-requested-contour/2656
**Category:** In Situ Support
**Created:** [September 30, 2019, 10:27am UTC](https://discourse.paraview.org/t/catalyst-script-not-rendering-the-requested-contour/2656 "2019-09-30T10:27:41Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![mdorier](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/m/eb9ed0/32.png) [@mdorier](https://discourse.paraview.org/u/mdorier)
#### Post date: [September 30, 2019, 10:27am UTC](https://discourse.paraview.org/t/catalyst-script-not-rendering-the-requested-contour/2656/1 "2019-09-30T10:27:42Z")

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EDIT: problem solved, see edit at the end.

I’m trying to have a sample code output a rendered image using Catalyst. The “simulation” is a simple code that computes a Mandelbulb fractal. It is then exposed to Catalyst using a vtkMultiPieceDataSet (though for now I’m just using 1 block on 1 MPI rank). I’m using ParaView 5.6 on my Mac, and the code is running on a Linux Ubuntu 16.04, where ParaView 5.6 is also installed (compiled with osmesa support).

I first used a Python script shipped with the Catalyst examples (gridwriter.py) to output the objects, then loaded the objects into ParaView on my Mac, added a contour, and generated the corresponding Python script (render.py) so that the simulation would do the same thing in situ.

Here is a picture of the ParaView interface on my Mac, with the options I used to generate the Python script:

 ![58](https://discourse.paraview.org/uploads/default/original/2X/5/5255eb5968aedb67c8505929389db499747b5c3d.jpeg)

When I use the script on the actual code to generate the same picture, I obtain the following image:

 ![RenderView1_0](https://discourse.paraview.org/uploads/default/original/2X/1/1c78ec2e8afd6b5671792e4bb86e27f1eebff107.png)

What am I doing wrong?

The full C++ code along with the Python scripts are available here for anyone to try out:

> **[mdorier/MandelbulbCatalystExample](https://github.com/mdorier/MandelbulbCatalystExample)**
>
> Example of code computing a Mandelbulb and outputing it using ParaView Catalyst - mdorier/MandelbulbCatalystExample

EDIT: problem solved by changing “vtkBlockColors” in ParaView’s drop-down menu to “Solid Color”. I don’t know why “vtkBlockColors” isn’t working, though.