After rendering an image sequence, but before rendering that sequence to video, the rendered images can be enhanced with a large variety of effects. Depending on the effects you want to add, there are differing levels of preparation before rendering initially.
Passes can be enabled for each View Layer to save additional data with each layer. That data can then be adjusted independently of the image in the compositing stage. Passes can allow lighting, shadows, materials and more to be adjusted.
Available passes vary dependent upon the render engine. Certain passes (and hence certain effects) can only be enabled with the Cycles engine. If a pass is missing, switch to Cycles in the Render properties.
Passes add greater flexibility to compositing but also add to render time. Only enable the passes you need for each layer.
- Default Passes:
- Combined - all passes included together
- Z - distance to visible surfaces
- Enable Passes:
- Select a View Layer in the top right of the program window
- In the "View Layer" tab of the properties panel, under "Passes", check or press any additional values
- Repeat as needed for each View Layer (view layers sometimes have different passes enabled)
Multiple view layers can be used to render more complex scenes when you do not have enough processing power. They can also be beneficial if you need to rerender
- In the Outliner window of your animation file:
- Create collections for each area that needs individual adjustments (ie. Lights, Foreground, Background)
- Name the collections descriptively (ie. Lights, Foreground, Background)
- Drag and drop items into their collections
- Create view layers for each area that needs individual adjustments:
- In the very top right of the Blender workspace, click on the new layer icon to add a new view layer
- Double-click on the layer to rename descriptively (ie. Foreground, Background)
- Enable and disable collections as needed for each view layer
- Select a view layer in layer drop down on the top right of the window
- Hide collections from the layer: uncheck the collections in the Outliner
- Hide a collection from the layer while keeping shadow/reflections interactions: keep the collection checked and right-click on the selection → View Layer → Set Indirect Only
- Mask out a collection so that unnecessary areas of overlap do not render on the layer: keep the collection checked and right-click on the selection → View Layer → Set Holdout
- Repeat for each view layer as necessary
- Enable additional passes for each view layer as needed
- For the view layer that conains the background (ie. the ground), in the View Layer tab, under "Light" check "environment"
- Adjust the output settings:
- Create and select an output directory for the renders (do not use the temp folder)
- Change the image format to OpenEXR multilayer
- Shorten the start/end frame numbers to just a few frames where the desired effect will be visible for a test render
- Adjust the render settings:
- Under "Film", check "Transparent"
- Save your changes
- Render the animation (Render → Render Animation)
- In the a new general file (Ctrl+N):
- Switch to the "Compositing" workspace
- Check "Use Nodes"
- Select (right-click) and delete (X) the "Render Layers" node
- Add and customize input nodes:
- Add an "Image" node (Shift+A → Input → Image) and place it to the left:
- Click on the folder icon and select your render folder
- Select all of the renders (A - select all or B - box select
- Click on "Open Image" in the top right
- Towards the bottom of the Image node, next to "Layer", select a view layer
- Duplicate the image node once for each view layer (Shift+D) - make sure to select a different view layer for each node
- Add AlphaOver nodes (Shift+A → Color → AlphaOver), placing them between the Image nodes and the Composite node:
- 2 view layers + 1 environment pass = 2 AlphaOver nodes
- 3 view layers + 1 envirnoment pass = 3 AlphaOver nodes
- Connect the AlphaOver nodes to the Image nodes:
- Start with the backmost view layer node and progress to the closest view layer node:
- Click and drag to connect the environment socket (Env) to the top left "Image" socket of the first AlphaOver node
- Connect the "Combined" socket to the bottom left "Image" socket of that same AlphaOver node
- Connect the same AlphaOver's right "Image" socket to the top left "Image" socket of the next AlphaOver node
- Connect the "Combined" socket of the next view layer (the) to the bottom left socket of the 2nd AlphaOver node
- Repeat the last 2 steps as necessary for any additional view layers
- Add a "Viewer" node in order to see the output (Shift+A → Output → Viewer)
- Connect both the Viewer and the Composite nodes to the last AlphaOver node by clicking and dragging from the right Image socket from AlphaOver to the left Image sockets of both output nodes
- Adjust and/or animate settings as needed
- Add additional nodes as needed
- Save changes
Bloom is a standard FX added in post processing because it can make objects really pop visually. It adds a more dramatic glow effect to emission materials. It is most effective when emission materials exist.
To setup for a bloom effect, add at least one emission material to something within the view of the camera.
- Make sure the render engine is set to "Cycles"
- In the "View Layer" tab of the properties panel, under "Passes → Data", check:
- Combined
- Z
- In the "View Layer" tab of the properties panel, under "Passes →Light", check "Emission"
- Setup a compositing file:
- Open a new general file (Ctrl+N)
- Switch to the "Compositing" workspace
- Check "Use Nodes"
- Select (right-click) and delete (X) the "Render Layers" node
- Add an "Image" node (Shift+A → Input → Image) and click on the folder icon to select your render(s)
- Add a "Viewer" node (Shift+A → Output → Viewer)
- Click and drag to connect the "Combined" socket of the Image node with the "Image" socket of the Viewer node
- Add a "Glare" node (Shift+A → Filter → Glare) - hover over the connection between the image and viewer nodes before releasing to place the node (it should automatically connect to the image and viewer nodes)
- Adjust the glare settings:
- Glare type - Ghost, Streaks, Fog Glow, Simple Star
- Glare Quality - Low, Medium, High
- Threshold - start at .5 and raise or lower as needed
- Other settings vary dependent on the glare type and can be changed as needed
-
Click and drag to connect from the right "Image" socket of the Glare node to the "Image" socket of the "Composite" node
In order to composite in sun beams, the animation needs an additional collection with objects that represent the base of the sun beams.
- Create a collection to contain the sunbeams source:
- In the "Outliner", right-click on "Scene Collection" to create a new collection
- Double-click on the new collection to name it descriptively (ie. Sunbeams)
- With the sunbeam collection selected, create a plane (or other mesh shape) for each sunbeam
- In "Object mode", use "Shift+A → Mesh → Plane" to create the planes
- Arrange the planes in view of the camera, where the light beams should begin
Sunbeams require the use of multiple "View Layers". One layer is required for normal objects in the scene. One layer is required for the sunbeams.
- Create and setup 2 View Layers:
- View Layer 1:
- Uncheck the sunbeam collection (unless the sunbeam source should be visible)
- All other collections should be checked
- In the "View Layer" tab of the properties panel, under "Passes →Light", check "Environment"
- View Layer 2:
- Rename descriptively (ie. Sunbeam)
- Leave only the sunbeam collection checked
-
All other collections should be unchecked (however if the sunbeam source should remain visible, leave the light collection checked)
- It can be helpful to leave a 3rd View Layer with everything visible in case you want to do some adjustment. In this case, turn off rendering for the "everything" layer
- Make sure the render engine is set to "Cycles"
- For both layers, in the "View Layer" tab of the properties panel, under "Passes → Data", check:
- Combined
- Z
- In the "Render" properties, under "Film", check "Transparent"
- Setup a compositing file:
- Open a new general file (Ctrl+N)
- Switch to the "Compositing" workspace
- Check "Use Nodes"
- Select (right-click) and delete (X) the "Render Layers" node
- Add an "Image" node (Shift+A → Input → Image) and click on the folder icon to select your render(s)
- Make sure the main viewlayer is selected (not the sun viewlayer)
- Add a "Viewer" node (Shift+A → Output → Viewer)
- Add an "AlphaOver" node (Shift+A → Color → AlphaOver) and connect it to the other nodes:
- Connect from the Image's "Env" socket to the upper "Image" socket from the AlphaOver node
- Connect from the Image's "Combined" socket to the lower "Image" socket from the Alpha
- Connect the AlphaOver's right "Image" socket to the Viewer's "Image" socket
- Duplicate the "AlphaOver" node (Shift+D) and connect it between the first AlphaOver node and the Viewer node:
- Connect the right "Image" socket of the 1st AlphaOver node with the top left "Image" socket of the 2nd AlphaOver node
- Connect the right "Image" socket of the 2nd AlphaOver node with the top left "Image" socket of the Viewer node
- Duplicate the image node (Shift+D) and change the selected View Layer to the sunbeams layer
- Add a "Lens Distortion" node (Shift+A → Distort → Lens Distortion) and connect its left "Image" socket to the "Combined" socket of the 2nd image node (the distortion makes the sunn=beams look more natural and less perfect)
- Add a "Sun Beams" node (Shift+A → Filter → Sun Beams) and connect its left "Image" socket to the right "Image" socket of the lens distortion node
- Add a "Blur" node (Shift+A → Filter → Blur) and connect its left "Image" socket to the right "Image" socket of the sun beams node (this softens the hard edges of the sun beams)
- Click and drag to connect from the right "Image" socket of the Blur node to the bottom left "Image" socket of the 2nd AlphaOver node
- Adjust the node settings as needed:
- Lens distortion: increase or decrease at least 1 distortion value and leave "Jitter" checked
- Sun Beams:
- Top values control the sun beam position/angle
- Ray length controls the length of the sun beams
- Blur: increase the X & Y values and keep the size at 1
- Click and drag to connect from the right "Image" socket of the right AlphaOver node to the "Image" socket of the "Composite" node