CG Jam

Image input node

Whats it for?? Image input node

exactly what it says it is, a node for adding images to your scene. But lets take a deeper look and find out just how powerful this node can be!

Whats it for?? Image input node

Sooo We finally made it through the input section!

The image input node quite simply allows you to composite an image into your scene, so lets have a look how that works.

 Render layer

First we have our rendered output of a suzanne on a transparent background, and we want to add her into an image. so to do this we need two nodes, the image input and an alpha over. we use an alpha over and not a mix node because we are using transparency and the Alpha over works better.

mix render and image with alpha over

Now all we have to do is open the file we want and we are done!

ok so that is the simplest use of this node, but we can do more. Instead of an image we can use an image strip, that is a sequence of images that form the frames of a movie clip.

so to start we just need to open the first image of the sequence.

As you can see we have a sequence of 100 images, you can see also there is a video file in the position of the second file, but don’t worry about this, blender will ignore it in favour of the sequence. so now we have our image sequence in the compositor, but we also have our render layer from before.

in some case you may want to add your current render to your strip, but in this case we are going to replace the old render input with the single image that we had before, and then we need to swap the connections to the alpha over node around so that the image sequence will be on top.

ok so now we need to tell blender to use the full sequence. simply click the button that says single image and you’ll see a list of options. select image sequence and change the frames value to match the number of images in the sequence, in this case, 100 frames.

you can decide on the start frame, so if you have a specific frame that you want your animation to begin you can define that here so if you type in 10 then the scene will render 10 frames before starting the image sequence. Alternately you might want to clip those 10 frames from the start of the scene, so you can offset the start frame, so if you put 10 in the offset as well, the scene will render from the start but the sequence will begin 10 frames in. Also instead of using an image sequence you can import a video file instead with these same options, which is really handy as the movie input node doesn’t have any way to manipulate the frames like this. So that all very simple now you can simply render your clip.


But that’s not the end!

As it is an image input you can bring in most kinds of image, whether its a png with alpha, a HDR environment map or a Multi layer EXR file. what this means is you can save your render layers into a single file and open them in the image input and the image input will behave in the same way as the original render layer node. We cover that in more detail in the video. It doesnt do GIFs however as they’re not supported by blender.

So well done, you now have a thorough understanding of the input section of the input nodes! we will be resuming this series very shortly but i have a few interesting things i want to show you so  hit the notification button and we will alert you to new posts as we deliver them! see you next time.


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