DaySky

DaySky is an image Generator. It needs no MediaIn because the image is calculated internally. Its only external input is an optional blue Effect Mask that spatially limits the generated result.

Resolve 21 describes DaySky as a practical implementation of A Practical Analytical Model for Daylight. It simulates daylight for a specific location and time and produces a high-dynamic-range image/map of that light. The distinction matters: it does not generate clouds and its output does not automatically become a 3D environment.

Latitude and Longitude define the modeled location while Day, Month and Time define the date/time state. Treat them as one physical input set: changing only Time while leaving arbitrary location/season values can produce a daylight state that does not match the intended reference.

Turbidity controls atmospheric scattering and absorption. Higher turbidity makes the simulation murkier or hazier. It is part of the atmospheric model, not a generic contrast, blur or saturation control.

DaySky is calculated in 32-bit floating point and can produce values far above 1.0 and below 0.0. Do Tone Mapping compresses that wide range into the selected exposure. Blackmagic recommends disabling tone mapping mainly when the result will be color-corrected later in a floating-point pipeline.

The Advanced tab separates sky-shaping terms. Horizon Brightness changes horizon brightness relative to the sky, Luminance Gradient changes the width of the transition, Circumsolar Intensity/Width control the area nearest the sun, and Backscattered Light changes the backscatter contribution.

The Image tab controls the technical Generator output: Process Mode, resolution, pixel aspect, Depth and source color/gamma metadata. The captured Resolve 21 Inspector labels the resolution-following switch Auto Resolution, while the manual describes the common behavior as Use Frame Format Settings; treat these as the same functional boundary rather than two separate features.

Depth is especially important with DaySky. int8/int16 reduce precision and range while float16/float32 are better suited to wide values and later floating-point grading. Turning Tone Mapping off and then intentionally quantizing the result to a low integer depth defeats much of the reason for preserving the wide range.

Source Color Space in the common Generator controls does not perform a full Gamut-style conversion; the manual describes it primarily as source-space metadata for downstream use. Source Gamma Space/Remove Curve belong to gamma/linear workflow rather than the daylight model itself.

DaySky Output is a regular 2D image stream. It can feed Merge as a Background, be processed by ColorCorrector/Gamut/Glow, or be used as a downstream plate/map. It cannot be wired directly to Merge3D as scene3d and should not be described as a DomeLight/IBL by itself.

To build a visually complete sky, add separate elements such as procedural noise/cloud branches over the DaySky base. This matches Blackmagic's own boundary: DaySky supplies daylight simulation, not a finished cloud system.

The bundled screenshots show the captured Controls, Advanced and Image tabs. Semantics were cross-checked against the Resolve 21 Reference Manual; live Resolve 21/21.1 execution was not run for this package, so numerical edge cases remain a target-build verification item.

Treat Location and Date/Time as one physical input group. Coordinates without a meaningful date/time describe an arbitrary model state, so matching a shot with Time alone is usually unreliable.

Day and Month are not decorative metadata. Season changes the daylight geometry at the same coordinates and clock time, so repeatable tests should lock the date.

Time is a DaySky model parameter, not the composition timecode. It can be animated, but Fusion does not automatically interpret the current frame as astronomical time.

The captured Inspector has no dedicated timezone or daylight-saving control. For physically strict matching, verify the time convention on the target Resolve build and document that convention in the project.

Tune Turbidity before creative grading. Downstream contrast or saturation can disguise a poor atmospheric setup but cannot correct the cause inside the daylight model.

Horizon Brightness and Luminance Gradient work in the same visual region but solve different problems: one changes relative horizon brightness while the other shapes the transition away from the horizon.

Evaluate Circumsolar Region Intensity and Width as a pair but change them one at a time. Intensity controls contribution; Width controls spatial extent.

Backscattered Light is part of the analytical atmospheric response, not a separate Light3D object. It changes the generated image only.

Do Tone Mapping is internal to the Generator and changes the branch pixel values before downstream nodes. That is different from merely viewing a wide-range image through a display transform.

Judge Exposure only when Do Tone Mapping is enabled. With tone mapping disabled, exposure/look adjustments are usually clearer in a controlled downstream floating-point stage.

Process Mode is a common Generator field-processing control. Full Frames is the sensible baseline for modern progressive delivery; field modes belong to genuinely interlaced pipelines.

Auto Resolution makes DaySky follow the frame-format context. That is convenient for timeline work but less suitable for a reusable fixed-size map when project format may change.

With Auto Resolution disabled, Width/Height become an explicit output contract. Document them in templates because they also affect processing cost and downstream sampling.

Pixel Aspect changes how output pixels are interpreted and normally remains square-pixel for HD/UHD work. It is not an artistic way to reshape the sun or horizon.

Choose Depth for the complete chain. A float32 DaySky does not help if the next node, cache or export immediately quantizes the signal; inspect the weakest link.

Color Space Type and Source Gamma Space belong to the common metadata/linearization boundary. They are not substitutes for an explicit color transform when pixel values truly need conversion between spaces.

Remove Curve and Pre-Divide/Post-Multiply deserve extra care when Effect Mask creates alpha coverage. They belong to the common image pipeline, not the physical daylight model.

For production comparisons, keep a documented control frame with fixed Location, Date/Time, Turbidity, Advanced and Image settings. Then look changes can be attributed to a specific stage.