TouchDesigner | The Container, Control, and Final Ouput

In thinking about how to meet the objectives that I had for this piece, one of my central questions was how to make sure that I could move through three cued scenes – either with manual or automatic triggers. I knew that I had three different aesthetic environments that I wanted to move through. I explored several different options, and the one that ultimately made sense to me given my current level of proficiency (at this point I had only been programming in Touch for a total of three weeks) in TouchDesigner was to use a cross fading approach. Here’s what the whole network looks like:

In thinking about how to ensure that I was being efficient I decided to encapsulate my three different scenes in their own respective containers. You’ll notice on the left hand side that there are three containers – each holding it’s own 3D environment. These are joined through Corss fading TOPs though a final composite (for a mask) until ending in a Null that was used as the display canvas. 

I spent a lot of time thinking about how this piece was going to be both interactive and autonomous. It needed to be interactive in that the user was able to see how their interaction with an object was driving the visual media; it needed to be autonomous in its ability to transition between scenes and then loop back to the beginning of the network. I don’t think I’ve totally cracked the nut that is the right balance of interactivity and self-directed programming, but it feels like I did make strides towards addressing this question. My solution to these issues was to allow the interaction with the projection to be centered around the control of perspective, but to drive the transitions through the scenes with time-line triggers.

Unlike some other interactive programming environments, TouchDesigner has a timeline built into the fabric of the control system. The Timeline is based in frames, and the programmer can specify the number of frames per second as well as the total number of frames for a given project. My Timeline triggering system was the following string of CHOPs:

Timeline – Trigger – Null

Timeline reports out the current frame number. The trigger CHOP can be set to trigger at a given threshold (or in my case a frame number). This in turn is passed to a null and exported to a Corssfade TOP as a rate for crossfade. The Crossfades are daisy-chained together before finally being attached to the null that’s output to the projector.

With the system working I also needed to make a mask for the final projection to ensure that I wasn’t displaying any empty grid onto the floor of the gallery where this was being installed. I would typically make a mask for something like this in Photoshop, but decided to try making this all in the TouchDesigner programming environment. My TOP operator string for this looked like:

Contsant – Transform – Blur – Composite

I started by creating a black constant that’s then passed to a transform so that it can be positioned into place. This is then passed to a blur to soften the edges, and finally to a composite to create a mask that contains a left, right, top, and bottom side. In hindsight I realize that I could use a single constant passed to four transform TOPs, to be a little more tidy. The mask as a composited object is then composited with final render stream before being passed to the Null that’s connected to the projector. 

 In the end I’m fairly happy with this project. t’s been a steep learning curve, but well worth the hassle, angst, and late nights. It’s no small thing to have made a piece of interactive media driven sculpture in a programming environment where that’s totally new to me. For as hard as all of this work has proven to be, I have to remind myself that I’m actively doing the work that I came to Graduate School to do. Everyday I realize that I’ve been changed by my time in the desert, and by my time with the gifted and brilliant artists and friends that I’ve found here. 

 Are these pictures too small? You can see larger versions of them here:

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