There is a scene I'd like to composite. In this case the desired result is to overlay some clouds on top of the mountains:
This works as long as the render resolution stays the same. For the sake of decreasing render times the percentage of resolution is set to 52 (so the image is almost 2 times smaller than final resolution).
Now once the result is satisfactory it would be great to increase the resolution to 100%. However if doing it just dragging the slider the render won't be satisfactory anymore:
Obviously clouds didn't take new resolution into account and are of the same size while the rest of the image enlargened. How to composite the render result so the overlayed images on top of it stay intact?
The node setup used for these clouds is one Scale node set to scaling relatively to input image size (so to enter fractions of 1 factors), then Translate node to move images to its place (relatively to input image size as well) and Rotate node. All of them are added to image after mist.
Convert Premultiplied is used here because of input png images I can't substitute which can't treat alpha normally (not related though).
As I thought it should help if Scale node is set up on Relative mode however it isn't related with output image, it will scale relative to input image so that's not what I'd like:
Relative
Percentage values relative to the dimensions of the image input.
manual
The straightforward solution is to edit values of the Scale (and possibly Translate) nodes in order to fit new resolution but that's quite unflexible as resolution might change once in while (also images to be overlayed can be anything, e.g. simple mask textures used as factors for other images etc).
How to overlay images on top of the render so when render resolution changes overlayed images continue being scaled respectively to the new image size?