Motion Background I created for our church. Originally made it like 15 minutes so it wouldn’t have to loop but I recently discovered the technique for seamless looping and was able to shorten it to 30 seconds.
After Effects project files included so if you want to play around with making the triangles faster, bigger, different colours, etc. You can play to your hearts content. You could also change the solid settings for the particle emitters and sequence size to make a triple wide background – do whatever you like! I hope you can learn from the project files.