Setting the scene/comp size?

So, in a thread, I gave the tip to do a subtle 2D animation on the comp to give the illusion of the camera moving, ever so slightly. It’s a trick I often use when using photos for backgrounds a.s.o… It might be a pan, a very slight zoom in- or out, well, you get it… But this movement is of course made withing the boundary of the comp size.

But the question is, what’s the best way to set the comp size in Blenders compositor? Is there really no other way to set the comp size other than the render layer input?

I haven’t actually thought of this before but it’s really weird not having a comp size setting - logically I guess that should be a value under the comp/output node… Letting the input determine size, that’s pretty bad, hehe…

Well, you do have the Scale node, if that’s what you’re looking for?

I’m pretty sure what I’m looking for just isn’t there; a defined workspace other than the size of the render layer which now is what determines the size of the output.

This becomes an issue if you want to scale and/or translate a layer in relation to your output. Of course there’s a workaround using any renderlayer as input and then use an alpha-over thus using the bottom plate to set the output size, but that’s not a very good solution… :stuck_out_tongue:

Edit: Like this. Here I use the alpha-over and the bottom layer size sets the comp/outpout size. Then I use a copy of it on top to be able to scale it within the boundarys of the comp/output size.


This actually seem like something they’ll probably realize when comping Mango, it’s more of an issue you’ll notice when comping plates from different sources…

I must say I’m really confused. The same result can be achieved without using the AlphaOver.

I’m missing something here, aren’t I? :slight_smile:

What you’re missing is, if you scale the layer (w/o the alpha-over) you also scale the output. I want to be able to scale or move a layer without affecting the output size. So if I input a layer with the size of 1920x1080 and scale it 10% the output will still be 1920x1080, though cropped. :slight_smile:

I agree with you, Farmfield, I found this to be troublesome, as well. I also came up with the same solution as you, just layer everything on top of any old renderlayer. It’s not clean or anything, but it does work. I do hope they fix it up a bit during Mango.

Yeah, I found a few such glitches during problemsolving the last few days… First I thought I was overlooking something, but no… :frowning: