The post called Simulating Video Feedback described how to build a simple paint action sequence that incorporated an Image Compressor ip op effect and a MSG rotation and scaling effect to simulate analog video feedback. This post take a second look at that post, and shows how to build this style of effect as a single MSG preset.
Some questions were asked on the Studio Artist User Forum the Simulating Video Feedback post. So I thought we’d take a second look at what is going on in the video feedback effect.
MSG IO Editing
Part of the user forum discussion focused on how to replicate the different Bus Streams used to build the MSG preset used within the PASeq preset that generates the video feedback simulation. Different MSG preset contain varying image streams in their internal Bus list. The Bus list is a list of the various streams that are available for use in a MSG effect. Streams take up memory, so you only want to have streams available on the Bus that are actually used in the effect. Some MSG preset are totally generative in nature, so they don’t process a source image. Because of that the R Src, G Src, and B Src input image streams are not necessary to run that kind of MSG preset, so they typically are not included on that MSG preset’s Bus.
Part of the confusion associated with the forum discussion on the Nov 8th post centered on users not understanding about how to replicate the Bus streams used in the Nov 8th post. The Bus list associated with any MSG preset is completely editable by a user in the MSG Advance dEditor, so if the R Src, G Src, and B Src input image streams are not available you can easily drag and drop them from the Stream Source LIbrary tab over to the Bus list.
Recursive Feedback Effects are often Parameter Sensitive
It turns out this particular effect is very sensitive to the parameters associated with the Image Compressor action step as well as the MSG rotation and scaling warp. The original post was also a little confusing because it shows 2 MSG action steps in the PASeq for the effect, but one of them was actually turned off when the video animation was generated. I did this at the time the first post was put together because I liked the nature of the video feedback simulation more without the second MSG action step after rendering out both options as animations.
You can build a single MSG preset that tries to emulate what is going on in the Nov 8th PASeq preset. It turns out that the Image Compressor action step used in that PASeq is actually very import to help generate the particular feedback textural patterning seen in the Nov 8th animation.
The MSG preset shown below tries to emulate the various kinds of processing going on in the original Nov 8th PASeq preset. Since one of the 3CRotateScale MSG action teps in that original PASeq preset was muted, we only need to incorporate 1 3CRotateScale processor into today’s MSG preset that tries to replicate the entire old PASeq preset.