Dear Dr. Rarden

Thanks for this wonderful tool a million times!

Currently, I am attempting to create an image that features multiple overlays, with the base image being semi-transparent in each hemisphere, only up to the midline.
I have tried adjusting the transparency settings of both the base images and overlays, but the result is still visually confusing, as the activation in each hemispheres remain visible through each other.

Could you kindly provide guidance on how to achieve the desired outcome?

Thank you,
Tammar

Tammar,
  I would create two bitmaps with MRIcroGL, using the clip planes and shaders so that one image shows the far hemisphere as opaque and hides the near hemisphere, while the other shows the near hemisphere with the nearby activations shining through. You can then use your favorite bitmap editor to blend the two together to get the desired effect. There is even an online tool for this:
  http://tma.main.jp/blend/