Greek letters

VisIt does not currently have a way to enter text versions of Greek letters for equations and annotations. There are other ways...

Image Annotations

It is possible to add an image annotation that contains the symbols that you want to include in your visualization. You will have to create the image in your favorite equation editor and produce an image of the equation. Screen capture is often a good way to create the image.

Pros:

  • Image annotations allow for a transparent color so you can remove the image background so the object of interest in the image integrates into the visualization more naturally.

Cons:

  • Image annotations do not automatically scale with the size of the visualization image.
  • Antialiased text is surrounded by a halo of color values that mix the text color with the background color. VisIt does not interpret those colors as being partially transparent when compositing the image into the visualization. In this case you will want to place the image over a similar background color.

Adding an image annotation

You can create an image annotation using the controls on the Objects tab of the Annotation window. Click the Image button to create a new image annotation. No image will be displayed in your visualization until you select an image source file and click the Apply button. The source of the image is a file created by another program. Once the image appears in your visualization, you can position it and scale it to fit your visualization. You can select a color that will become transparent too if you want to remove the image's background so it does not obscure your visualization.

Imageannot1.png Imageannot2.png
Image annotation controls Equation image in a visualization

Python

Here is how to create and manipulate an image annotation from Python.

# Set up a plot
OpenDatabase("noise.silo")
AddPlot("Pseudocolor", "hardyglobal")
DrawPlots()

# Create an image annotation and make it use an image called "greek.png"
img = CreateAnnotationObject("Image")
img.transparencyColor = (255,255,255,255)
img.useTransparencyColor = 1
img.image = "greek.png"
img.position = (0.27, 0.88)

# Print the img object to see what other properties you can set.
print img