rending multiple scenes

hey, this is the first time i’ve ever used nodes and i have no real idea what i’m talking about, i’ve decided to use three render layers, one for the main image, one for vector blur, and one for depth of focus, but i don’t know how to render all of them together.

that’s as far as i got, i’m sure i’m making some elementary mistake, but i don’t know what it is

all help appreciated, thanks in advance

If I understand you correctly you can do the blur and the other things and
want to combine the images back together again.
You need to take the output from each of your render layers after they’ve
been blurred and stuff and then probably use one of the ‘mix’ node options to combine them.

Rather than Color>Mix, one of the more common ways of re-combining Render Layers is by using the Color>Alpha Over node.

However, looking at your prelim noodle (the node arrangement) it looks like you may be going about things wrong – do you want to add both Defocus and Vector Blur to the Main Image? If so, you need to do this with nodes added one after another, using the Main Image (“Standard”?) Render Layer as the only source. The “pipeline” from the Main Image Render Layer might be Main Image RL -> Vector Blur node -> Defocus node -> Composite node (in the Output menu options).

But be aware that both the Defocus node and the Vector Blur node can introduce artifacts, so you may have to tweak the setup extensively. including adding other nodes, to get the best results.

Multiple Render Layers are usually used when you want to apply a node effect to only certain objects in a Scene, for example, a moving figure might get Vector Blur, but you wouldn’t want to include the background in the VB node calculations if it isn’t moving much, so you could use two Render Layers to isolate the figure and the BG. After doing the Vector Blur operation, the figure would be re-combined with the BG using an Alpha Over node.