Post effects
Effects that run over the rendered image: bloom, depth of field, motion blur, anti-aliasing, outlines, auto-exposure, and the lighting effects that read the whole frame.
Once the renderer has lit the scene, a chain of post effects runs over the finished image. Every one is a toggle, and each costs GPU time only when it is switched on. The image effects are all off to start with; the ray-traced lighting further down is the exception, and is on.
These effects work on the rendered picture as a whole, so they sit downstream of lights and materials. Use them last, once the scene already looks right.
Most of them live on the Render Settings node, which is one per composition. Depth of field and anti-aliasing are the exceptions: they are per render, so their controls are on the Render node itself.
For grading, filtering and warping an image as a node in the graph rather than a toggle at render time, see Image effects.
Lens and camera effects
bloom_enabledbleeds a soft glow out of bright areas, for neon, highlights and anything emissive.bloom_thresholdis the HDR luminance above which a pixel glows, at 1, andbloom_intensityscales the glow.dof_enabled, on the Render node, throws the foreground or background out of focus so a chosen distance stays sharp.dof_focus_distanceis the focal plane in scene units,dof_focus_rangehow far either side of it stays sharp, anddof_max_blurthe blur ceiling in pixels.motion_blur_enabledsmears moving things along their direction of travel, reading each object's actual on-screen movement from the velocity buffer. A fast object stays crisp where it is not moving, and the object behind shows through its blurred edge.motion_blur_intensityandmotion_blur_maxon the Render node scale it.auto_exposure_enabledbrightens or darkens the whole frame so the image stays well-exposed as the scene's lighting changes.
Both also exist as a blur_type on the Blur node: Motion Blur, which averages over a shutter window in frames, and Depth of Field, which needs a depth pass wired into its depth_in. Use the node to blur one specific object or image, and the post effects here to smear the whole frame from real motion vectors.
Anti-aliasing (TAA)
Anti-aliasing smooths stair-stepped, jaggy edges. The method here is temporal: taa_enabled on the Render node blends a little of the previous frame into the current one, averaging out the rough edges over time. It is off by default. It needs to know how things are moving on screen, and reads that from the same velocity buffer motion blur uses.
Because TAA blends across frames, a completely frozen, super-fine pattern can shimmer slightly on the very first frame before it settles. Normal animated use does not show it.
TAA is the live view's method only. An exported frame is anti-aliased a different way, and always: the renderer takes several sub-pixel-jittered passes over the whole frame and averages them before the tone map, on both integrators, whether or not taa_enabled is on. A jaggy viewport is not a preview of a jaggy export.
Outline
outline_enabled detects depth and normal discontinuities in the rendered scene and strokes them, for a stylised, illustrated or technical look. It works on whatever geometry the renderer is fed, with no extra setup. outline_threshold sets how sensitive the edge detection is, lower catching more edges; outline_strength sets how visible the stroke is, and the three outline_color_* channels its colour, black by default.
Lighting that reads the whole scene
A few effects let light interact across the whole scene for real depth. Ray tracing drives them by default: what is already on screen is read first, then rays are traced into the actual scene to catch what the screen cannot see. All of these are on the Render Settings node, covered in The render node.
Ambient occlusion darkens creases, contact points and tight corners where light struggles to reach, grounding objects and adding depth.
rt_aois on by default and traces for the contact shadows the screen alone would miss, out toao_radiusworld units.ao_enabledis the screen-space method that stands in when ray tracing is off; it needs a perspective camera.rt_reflectionsmirrors the rest of the scene in glossy and metallic surfaces, so a shiny floor picks up the objects standing on it. What is already on screen is reflected first, then rays fill in anything off-screen or hidden behind another object. Off by default, because it costs more.rt_giis bounced, indirect light: colour and brightness spill from one surface onto nearby ones, the way a red wall casts a warm tint on a white floor. Also off by default; turn it on for softer interior lighting.Refraction and caustics bend and focus light through glass, water and liquid, including the bright focused patterns caustics create. They come with the material rather than a toggle here. See Materials.
The fast first pass only knows what is currently on screen. Ray tracing fills in what is off-screen or hidden: for shadows and ambient occlusion always, and for reflections and bounced light once they are enabled. Nothing drops a tier for you when a frame runs long. rt_quality and rt_shadow_budget are the dials, and both are yours to set. See Making it faster.
Turning them on
Post effects are configured as part of the render setup rather than wired in as separate nodes. Add a Render Settings node for the composition-wide ones and use the Render node for depth of field and anti-aliasing. An effect that is off costs nothing, so leave the unused ones switched off to keep playback fast.
post_process_order on the Render node is a comma-separated list. Reorder it to change how the effects stack.
To temporarily disable any node feeding the picture, use Bypass rather than deleting it.