Vertical ouput

[Lightupyourlife]

Hello, I'm a 16 year old new user of Arena.
I would like to project a composition on a wall that is higher than wide (6meters high vs 3 meters wide). I only have one videoprojector (1920*1200). I suppose the only option is to place it far enough from the wall and in a vertical position. But all what I configure/do on my laptop is projected like a 90°rotation was applied....

I can modify input selection to 1200*1920 and represent door and windows as accordingly slices.
I can rotate my clips with transformation tool so that they appear in the good direction on the wall.
But I can not manage to use the edit points (output transformation) since when i move the upper left corner of my slice to fit with the upper left corner of the window, I see on the wall its upper right corner..., the bottom left corner of the door's slice is near its real upper left corner aso...

Is there any way to do it easier ?

Thanks a lot for answering,

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Light up your life is my dream

[Zoltán]

I'd make an 1200x1920 composition, and play all my content in that, so what I see in the UI will match the projector. No rotated clips, unless you really want to.

Then in the Advanced output, map the input slice to the output slice, match output slice to input slice using right click menu, and rotate the output slice.

[Lightupyourlife]

Thanks for your reply, I'll try like this