Eraser tool?

Hi,

I mostly work with Davinci and am a noob in the Fusion page. However I need to create a mask for a mapping project. The mapping is quite complex and the "Transform" is not enough. They easiest would be to erase the pixels not needed of a 16:9 image . Is there something like an eraser tool in Fusion that acts like the eraser in Photoshop or After Effects where you simply delete pixels? I coudln't make "Mask Paint" work that way, but that just might be my inability.

Thanks for the help / tips.

Best

If you're saying you want to erase the pixels that are not needed for a 16:9 image, it sounds as if the aspect ratio of your footage isn't the right fit for your project.

In that case you can use a crop tool (in the transform section) to just cut off what you don't need.
Or you can use the letterbox tool. Or you can create a background that does have the right frame format for your needs and then adjust your footage and merge it over that background.

Without slightly more info about what issues you're actually encountering it's difficult to give you better advice from the top of my head.

Thanks for the info.

The aspect ratio is not the problem. I try to explain the situation better: It is for fixed installation that works the following: The beamer projects through a hole in the ceiling on a convex mirror which then projects the image on a 16:9 surface hanging from the ceiling. this way creates quite some weird distortion and I don't need the distortion to be fully rendered out of the image, but to have it fit the 16:9 surface without overlapping. I tried different tools (e.g transform) but the distortion / overlapping is so weird that I found after 3h of trying only erasing precisely pixels will make up for a clean mask in the end.

Is this more clear now? And if yes, is there a pixel-eraser tool?

This is a very specific problem you're having. I still don't quite understand what you're looking for, but if you're looking into a simple way to paint away a couple of pixels, just use the Paint tool.
Set it to Stroke instead Multi-Stroke and set the color to be black with an alpha of 0. This will let you paint holes in your footage.

Pixels won’t go anywhere, you can only make them black and zero their alpha as Sander wrote. You can use all regular roto and paint tools to do it, what doesn’t work for you?

It is very simple to do: