thanks Mark!

I wouldn't spend the time to clone the information over (never a great idea), rather I would just include a link to the help desk from the support section of the site. It will be easier to maintain that way.
You would just need to remove the add ticket link?

Back in March I had an opportunity to see a production called Kindur put on by the Italian Company Compagnia TPO. One of the most beautiful and compelling effects that they utilized during the show was to use a live-camera to create a mask that revealed a hidden color field. The technique of using a live feed in this way allows a programmer to work with smaller resolution input video while still achieving a very fluid and beautiful effect.  This effect is relatively easy to generate by using just a few actors. To star this process we'll start with a Video-In Watcher actor. The video-in will be the live feed from our camera, and will ultimately be the mask that we're using to obscure and reveal our underlying layer of imagery. This video-in actor connects to a Difference actor which looks for the difference between two sequencial frames in the video stream. This is then in turn passed to a Motion Blur actor. The motion blur actor will allow you to specify the amount of accumulated blur effect as well as the decay (disappearance rate) of the effect. To soften the edges of this the image stream is next passed to a Gaussian Blur actor. Finally this stream is passed to an Add Alpha Channel actor by passing the live feed into the mask inlet on the actor. The underlying geometry is then passed in through the video inlet in the Add Alpha Channel actor. Finally, the outlet of the Add Alpha actor is passed out to a projector.  As a matter of best-practice I like to use a Performance Monitor actor when I'm creating a scene in order to keep an eye on the FPS count. This can also be useful when trying to diagnose what's causing a system to slow down during playback.  This effect works equally well over still images or video, and is certainly something that's fun to experiment with. Like all things in live systems, your milage may vary - motion blur and gaussian blur can quickly become resource expensive, and it's worth turning down your capture settings to help combat a system slow-down. You can see my full documentation set here:  http://matthewragan.com/2013/04/28/isadora-live-camera-input-as-a-mask/

Exactly my thoughts. Unless I'm dealing with a sensor that's wifi only, I'd much rather have a hardline for a production / installation stability. Even if only for the little bit of inner peace it brings.

Great!! I'm having loads of fun turning video signals into dmx :)

Thanks so much Mark. I'd been trying to avoid this multi-file solution so that I could be more spontaneous, but I understand the logic. That patch is much more elegant than how I'd been doing it. Much appreciated

Glad this was useful vanderzee.

Thanks Rick. I was just pointing out the error in the help docs.
I once tried to use this method to read each pixel.. but found the positioning rather difficult.
I have been (like you I guess) using it to read a matrix of values from video and map to DMX.. works well.
 Just haven't got it down to scanning ever pixel, I'm defining tiled regions.

Its very low quality I am afraid... I did it a while ago but it might help get you started...

[http://vjskulpture.wordpress.com/2012/06/28/isadora-data-array-actor/](http://vjskulpture.wordpress.com/2012/06/28/isadora-data-array-actor/)

But you are right that for simple triggers these would suffice. Except that I already have audio

Dear Mark, dear all,

I have been struggling for too long with matching chopped videos with differing non-standard aspect ratios when projected onto a set stage with two 3D Quad distort actors. I have come up with an empirical user actor (attached here) to output the somewhat required driving parameters: the aspect ratio modulation factor (aspect mod input of the 3D Quad distort), and the three spatial factors for which the stage will be covered from -100 to +100 (-xmin,+xmax, -ymin,+ymax, and -zmin,+zmax). For the z-depth, I was more concerned by the zero (initially set at -2.5 in the 3D Quad distort). The inputs of this Piece normalization actor are the matrix size of the chopped videos and the stage number (to extract its matrix size).
Fine, it works for most of the configurations I had faced so far. The attached screenshot of the main part of the actor for (128x256), (1024x768) videos and a (960x540) stage is a workinig case. However it is ad hoc and it sometimes fails. The matching is not good and the superposition of the two videos does not work.

I guess there must be equations to rule all this better than the one I came up with.

First, I do not know why the z translation zero is for standard resolution -2.06 (not -2.5) and, for the others, an integer number of -2.06 Second, the equations that work for aspect ratios greater than 1 differ from those for aspect ratios lower than 1 Third, why the initial values for the 3D projectors differ from one to another (-150 for the 3D Rect Project...)

Anyway, would you - Mark, I guess you have - have a clue on how to handle the aspect ratios and ensure matching? I would really appreciate.

Thanks for your help,

Ikse

6e90b3-aspect_ratio_adjustment_actor.jpg f9e091-piece-normalization.iua

Thank you vanderzee!

It seems like After Effects is always teaching me something about Isadora, and vice versa. Be patient with yourself when it comes to After Effects - that piece of software can feel like a bit of a rodeo at times. 

A follow-up a post about sliders. This time around it's using buttons.This is probably too basic for the people here, but might be useful when you're teaching someone the ropes.

http://matthewragan.com/2013/05/20/isadora-button-basics/

Thanks a lot.  I get it.

Thanks MatthewH. I've used dedicated setup scenes. The Data Array actor could produce a generic solution adaptable to individual performance needs.

Don't know if the question was about displaying text or reading text from a file, but if the latter, you should consider using this: http://troikatronix.com/community/#/discussion/694/read-text-from-a-file-i-wrote-a-plugin

Please use this topic to offer further insight regarding, or to suggest improvements to, the Knowledge Base article [How to Install a Second Version of Isadora on the Same Computer](http://troikatronix.com/support/kb/how-to-install-a-second-version-of-isadora/)

**Please use this topic to offer further insight regarding, or to suggest improvements to, the Knowledge Base article [How to Delete Isadora's Preferences](http://troikatronix.com/support/kb/delete-isadora-preferences/)**

Please use this topic to offer further insight regarding, or to suggest improvements to, the Knowledge Base article Moving an Isadora Show To Another Computer.

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