Contour Opacity and Vector Visualization Combination

Unique post-processing results can be created by combining different visualizations. The steps below go through editing a contour to be semi-transparent contour so that a vector field on the same plane can also be seen. This is helpful as contours alone does not always intuitively indicate direction of the flow. Likewise, vector coloring may not be strong enough or spaced in the best manner to display desired results. Combining visualizations can help with these issues.


To create this visual:

  1. Load Tutorial 4.ifx from the downloaded tutorial zip file.

  2. Turn off any visualizations that are already showing in the 3D window.

  3. As vectors only show the variable 'velocity magnitude' a new contour will need to be added to the project to match the vectors variable - from the Add Items tab, select Contour from the Select Item dropdown menu.

  4. Set the Simulation as Westerly, 5m/s

  5. From the Variable dropdown menu, select Velocity Magnitude, m/s

  6. Set the On Plane to XY and enter a height of Z = "1.5" as the Offset At value. This height was chosen so that the contour and the vector field were on the same plane and thus would display the same results.

  7. Set the Relative to value as Domain and ensure the Auto-Range checkbox is selected, and click the Add Item button

  8. Change the opacity of the contour by selecting it in the Project Items tab and under the Appearance section expand the Color Map information. Here you can edit the opacity value as indicated in the figure below. A value of 0 will make the contour fully transparent, a value of 255 will be fully opaque. Enter a value of "150" as the Opacity and click off the panel to confirm the value. You should now be able to see more of the CAD file beneath the contour, such as the extents of the ground as in the following figure.


    Tutorial 6 - Figure 76 - red arrows indicating the process of changing the transparency of the contour, "performed" from top arrow to bottom arrow


  9. Toggle on the visibility of the vector field by clicking the checkbox next to Vectors at 1.5 meters in the Project Items tab. Now with the semi-transparent contour we can see both visualizations at the same time.


    Tutorial 6 - Figure 77 - Example of using transparent contours with a vector field showing velocity magnitude of a wind simulation


  10. Try changing the color map of both the contour and vector field.

    Tutorial 6 - Figure 78 - changing the color map of the transparent contour and vector field to better indicate low velocity regions