nooby question - why is my green screen attempt not filling the output window?

Support Compositing and Post Processing
1

Hello Brothers, Sisters and Others.

I am trying to do a green screen effect in compositor. I have a 1920x1080 25fps video file, which I have already massaged in ffmpeg. I also have a 1920x1080 png which is what is viewed where the green is. I have the render output resolution to 1920x1080 as well. So, I render the frames and I end up with a 1920x1080 video, but the video is a small rectangle in the middle of the screen with large black borders. It is the same if I look at the individual rendered png files. It is as though I have moved the camera back or suchlike? I don’t think it is the node processing, and adding scaling there does not seem to fix things.

I am less than one week into learning blender, so please be easy on me. I have been watching lots of youtube tutorials etc but am still learning to use the gui and the keys…

Thanks

2

You may have a render border activated (The red square over the camera view activated by ctrl+b)

Disable “border” in the render tab under dimensions :slight_smile:

3

Hello Jamie B,

I did not have the border activated, and activating does not change the result. I press ctl b and get a cross-hair over my node display. I think I cannot see the camera view. How do I get it to display?

Thanks

4

hmmm, can you post a .blend file?

edit: do you have the render dimensions scale at 100%?

5

I can’t find the dimensions scale… It is all quite a bit to absorb. I have attached the .blend file.

Thanks

Attachments

sermon1_sin.blend (579 KB)

6

Ah yes, the scale is at 100

7

Okay, You need to first add a camera, then render :slight_smile:

Then it should work as expected.

By the way, once you have rendered the image, you can just plug the image texture node directly into the composite node.
To view changes real time, open the UV editor and you should see the image “render Result” displaying :slight_smile:

Let me know if this fixes the problem for you

8

If you are just using the compositor for image editing, in the render tab, go to the “film section” and tick transparent.

This will make the world render out as alpha :slight_smile:

Then edit the image texture as you would a rendered image in the compositor :slight_smile:

9

HI Jamie, so I could not find the camera… So, I started with a new clean startup and then added in the nodes. And it is working!! Praise and rejoice.
I am still looking into your other suggestions, no doubt I will be back to ask more of them.

10

Glad its working for you! :slight_smile:

To add a camera, go to the 3d viewport and press Shift+A and then select camera from the drop down menu. Or just press Shift+A and then R and it will add a camera into the scene.