Many of you have seen Bryant's grain in his lenses that move which I assume is a gif. Now the downside to a gif is that it loops and takes up a decent amount of storage in your lens which could be used for other things. So I wanted to share with the community how I was able to make a moving, fully customizable, and randomized grain overlay!
The first thing you want to do is add a graph empty in your resources panel, from there click on the material editor panel. Then using the tab key create and connect the nodes in the way the photo below shows. Each node plays an important role in creating the grain. The screen UV coord node grabs the coords of the current surface which in our case will be our screen. This then feeds into the scroll coords node which scrolls the coords over time. Connect this to the simplex noise will create random values using simplex noise. Connect a float parameter to the scale input to be able to scale our grain to the desired size. Connecting these nodes to our shader completes our graph!
Once the graph is complete create a screen image and set the stretch mode to fill. Then drag and drop the new material that we just created (our graph empty if you didn't rename it) over the screen image's normal material. Set the blend mode to multiply and bam you have moving grain! In order to change the size/scale of your grain double click on your material and you should see an empty box under Graph parameters in you inspector panel. You can change this number to whatever you would like to make your grain bigger or more fine. The perfect amount for me is 300. If you were unable to follow the tutorial I have also linked my website below if you would like to download the material!
Feel Free to check out my new YT channel here: http://youtube.com/c/RyanShields88