Corner Pin problem

[Dmitriy]

Hi there.
I have the following problem with Corner pin in Nuke: I want to put a small object over a 2k footage. The resolution of the small object is 2k too. so when I put it over, I need to apply some transformation to it. and when I connect a Corner Pin node to this small object, it's vertexes are situated in the corners of the frame that makes work almost impossible, because I lose opportunity to zoom in. In Shake I solve this problem using a Crop node. In Nuke this method is vain. What should I do?
Thanks.

[nathan]

I don't quit follow you, how can it be a small object if its also 2k? Do you mean the area of interest inside the 2k image is small? Regardless I still don't quit follow what it is your trying to do, maybe a screenshot would help?

[Dmitriy]

Yes, the area of interest. everething around it is black.

[nathan]

Why are you transforming and zooming with a corner pin might I ask? Sounds like a simple transform node do what you need. if you also want to use a corner pin then first add a transform node and do the transforming and scaling then add a corner pin afterwards to warp the corners around.

[Dmitriy]

I don't zoom with Corner Pin) Imagine that I need to change someone's face. So I put a new one over the original footage. And I want to add some perspective with Corner Pin. so when I connect CP the vertexes are too far from the face's edges - they are in the corners of 2k frame. and I want them to be closer to the face. The face that I put over is cut from the first frame of the original plate.
Sorry if I speak enigmatically.

[nathan]

Ah I get what your saying now, you could either use a spline warp or you could crop off the area you want to corner pin along with reformatting its width and height, then use a transform node to reposition it back to its original spot and corner pin from there.

[Dmitriy]

Yes, I get it. How can I reformat without changing the resolution quality? In Shake I use Window node for this. In Nuke Reformat node changes the resolution.

[nathan]

Reformat has a few different modes that wont effect image quality, also crop has a reformat option built in that you can use by checking the reformat check box inside the parameters.

[Dmitriy]

Oh I see that. Thanks a lot for your answers=)

[rueter]

The easiest way would be to use set the source bounding box in the CornerPin's "from" tab. That way you don't have to crop anything and have full control over where your warp points are.

[Dmitriy]

but when I change the values in it, the image changes too.

[Diogo Girondi]

Just temporally disable the node so you can set the 'pin offsets' without having the image updated.

[rueter]

it's like a source target warp to control which points of your image are pinned. Of course moving them will change the image as the area inside the "from" corners is mapped inside the target corners to give you the control you're after. Once you start aligning the corner pin on your background everything will look fine again.