I've mentioned that I love Isadora, and I have a lot of patches that might be useful so I'm going to try and share a few here.   If you have any problems or questions about Isadora feel free to ask me, and I'll see if I know or can figure out how to help.

You will have to have "the newest" or close to newest version of Isadora to open my example files (1.2.9 on the Mac, or 9b51 on the PC)

One of the things I love the most about Isadora is the Quad Distort Actor.   I had been using my own cobbled together software in which this was the primary feature, and when I started using Isadora I though that it was so much better than everything I had tried, if only it had this one more feature.  Well Mark added the feature and I was hooked.

The simple explanation is that a Quad Distortion actor is just Like a Projector but you can control it's corner points to correct for even radical keystone distortions.

I think this is obviously useful, but I want to point out some of the great things that it makes possible.

• Your projector just can't quite go in the center of the screen.
  • use the Quad Distort to fix it in software
• You want to project behind actors, but don't have the space for rear projection
  • if you have a high grid put the projector up as high as possible, point the projector down onto your back screen at a very steep angle
  • this lets the actors walk up very close to the screen before shadwos apper
  • use Quad Distort to correct for the keystoneing, You can correct for much more radical keystonging than what is built into the projectors.
• your in a hurry on install, like all tour situations
  • just throw up the projectors in roughly the right spot, overshoot
  • and correct it in software with the quad distort actor.
  • (fix it after rehearsal if you have the time)
• you are projecting on scenerey that is not perpendicular to the stage, or not the same scenery from scene to scene.
  • use Quad Distport, hit the wall in this scene, and the park bench in the next scene
• You want to project on everything even actors
  • use a really big projector to cover the stage and quad distort to create multiple smaller "virtual projectors"
  • put a DMX mirror in front of a projector and recorde multiple focus settings, each with their own Quad distort settings.
• Your really tight on space and want to bounce the image off a mirror to cut the throw distance
  • Focus and alignment off a mirror is very tricky, but just get it as close as possible and use Quad Distort to do the final tweeks.

OK so back to the example patch:  here is the quick way to look at it, an explanation of the what and why of it all follows in more detail.

About the example patch.

1. unzip
2.  open patch
3. go to the second scene video 1
4.  show controls
5. show stages
6.  drag around the controls and see what happens

While the idea of replacing a Projector Actors is simple in theory there is more work to be done after that switch.  The main part of that is to actually set the values for the corner points, in fact it's very difficult to just correct those corner points directly on the actor, so I have made a patch with a bunch of controls hooked up so that you can simply drag around the corner points in what I hope is a simple logical way.

But there is one more wrinkle.  If you are building a show with only one file and just the one projector actor then there is no problem setting this up to match your installation.  But if you are using more than one scene then you would quickly notice that it is a pain to have to do the corner point correction on every scene, so what I do is set up the quad distort and the controls on scene 1.  
Then in each scene I "activate" the first scene and use a broadcaster and listener to send video to the same quad distort actor.
That's why you have to go to the second scene to see the video, but most of the actors are in the first scene.

That solves the problem but it does have it's won consequences.  For instance if you tend to use the Jump actor to switch scenes with a xfade value to crossfade between scenes then my using only one quad Distort won't work.
There are other solutions, but it just gets more complex as and I'm not sure what you need.  But I'd be happy to advise, or add things to this patch or your patch if you like.

Let me know if it's helpful or confusing.