what do you mean 'i am unable to scale a layer...'?
what do you mean this simply isnt working for this show?
- this is the way to do this - im in spain right now - doing a show with exactly this-
you need to figure out how to do this - it is imperative - its the only way to be able to scale and move layers on object.
did you need to follow the steps i indicated?
Did you create a test image with the correct aspect ratio for the stage object?
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Practise...
you then practise - set up a projector by yourself in a room- and practise setting up the mixes so that they align onto various points corners or objects in a room.
get a feel for how you set up the mixes to project onto different objects or surfaces in a room.
try different walls or cupboards etc.
watch how perspective projection works.
watch what happens when you move an object on a keystoned mix-
get out of the theatre - and into a private room.
practise moving a white blob from one corner to another- or up and down a wall.
Ask yourself :
"Did i setup the corner points correctly?"
"How accurate does this need to be?"
check and double check.
study...
You should also study the nature of perspective-
and perspective drawing:
http://www.khulsey.com/perspective_basics.html
watch how the size of windows on a building changes as it recedes into the distance?
windows with the same dimensions are the most useful - then you can see how they change shape?
imagine each one of those windows is a surface onto which you have to project an image?
see what happens?
what happens if you only have a single projector- can you see how the shape changes?
perpective and perspective mapping - and its inverses - are non-linear - every single point in the world has a unique perspective and a unique projection.