Drifting and Superimposed Colored Gratings

Coding
1

Hello,
I am trying to reproduce an experiment where two colored laser-generated fringes (Red and Green) are superimposed and are drifting in opposite directions.
I have used the example of the Blue-Black GratingStim and can display a red-black GratingStim for a given number of frames and using setPhase(0.1,’+) to allow drift. Adding the green-black GratingStim on top does exactly that and I cannot see my red grating anymore.
I would like some advice on how to simulate my experiment in PsychoPy.
Many thanks!

2

GratingStim has an opacity parameter, try adjusting that for the grating on top.

- Allen

3

Thanks for your help @AllenIngling ,it works with addition of win.setBlendMode(‘add’).

  • Sab