Draw on ONLY Visible pixels

[Toaddd]

So i am new using affinity, started today using it.
So i put an image (ignore the image, i just placed random image) and i tried to paint it (using mask and pixel layer) and didnt work
does anyone know how?
also its 1280 x 720 px

[walt.farrell]

Welcome to the Affinity forums.

First, if you Place an image, you will get an Image layer. If you really want to paint on it, it should be a Pixel layer. Depending on your Assistant Settings trying to paint on it may automatically Rasterize the Image layer and convert it to a Pixel layer. Or you may need to right-click on it in the Layers panel and choose Rasterize.

Next, if you look at the Context Toolbar when you have the Paint Brush Tool selected, you should find an option named Protect Alpha. If you don't see it, but you do see a double-chevron (>>) on the right edge of the Context Toolbar, click it to expose options that are hidden because the screen/window is too narrow. If you enable Protect Alpha, the brush will only paint on pixels that are not fully transparent.

Finally, it's hard to be sure from your screenshot what you actually have. If we could see the Layers panel, and the Context Toolbar, and (really) everything in the application window there is often more information that will help in answering questions. So a more complete screenshot is usually better. It's also hard to be sure what you have because those black areas could be either empty, or black pixels. In Photo you'll find an option in the Document menu labeled Transparent Background that will clearly show pixels that are transparent.

[Toaddd]

Thanks it worked!
Also about the last part, also My bad about the first section of it, and for second one, it just a gray fill layer
Again it worked, Thanks Walt!