How to offset Anchor Point of an image?

lunelson's picture

Hi,

I'm new to the forum, and working on a means to move/scale/rotate an image in QC. So far I'm emulating the way I would control an image I've placed in a program like After Effects. I have managed to get fairly fair; but I am wondering how I might build the equivalent of an anchor point offset for an image -- assuming there isn't a function like this built in.

If you imagine for a moment the way you position an image in AE: place it in the comp, and give it a position of [0,0], for example. If you offset the Anchor Point, by say [-500,0], the image will of course "move" to the right -- the same as if you had changed it's position by [500,0]; but the difference is that if you scale or rotate the former, it rotates or scales around [0,0] since it's Anchor Point still positioned there; whereas if you rotate the image with changed position it rotates around its own center, since it's Anchor Point is still centered on itself.

This offset of the Anchor Point, without changing position, is what I'm trying to achieve in QC, but I can't figure out how to do it since the Image Transform patch does not have controls that correspond to this. It does have "Origin" and "Translate" which sound like they should do something but don't seem to do what I expect. Can anyone suggest what order of patches will do this?

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cwright's picture
Re: How to offset Anchor Point of an image?

You're combining two ideas into one (incorrectly).

In QC, you have textures (image), and you have consumers (renderers). Image Transform will modify the image, but not the renderer.

you'll want to use transformations and inverse transformations to rotate about an arbitrary point (kinda like this limited example)

PreviewAttachmentSize
rotateAboutAPoint.qtz3.45 KB

lunelson's picture
Re: How to offset Anchor Point of an image?

Hey cwright,

thanks for that! You're ('limited') example was enough to solve it for me, in this case!

All the best, LMN