ANR Glow

Overview

Glow finds the bright parts of the image and spreads their light into a halo. The halo is built from several blur sizes at once, from a tight core to a long, soft tail, so one node gives the falloff of a real lens bloom; Halo Spread balances the tight and the wide parts. Use it where you would reach for Nuke's Glow: practical lights, neon, muzzle flashes, sun glints and hot CG highlights.

Threshold and Soft Knee choose which light glows, in scene-linear values: by default only values above 1 glow. Glow From measures brightness by luminance, by the brightest channel (to catch saturated colours such as neon or tail lights), or by alpha (to glow a matte, text or a logo).

The Shape and Color controls stretch the glow for an anamorphic look, add horizontal streaks, split it into coloured fringes, and set its saturation and tint without changing the image underneath. To glow only some of the lights, connect a matte of them to Glow Area: the others stay as they are, and the halo can still spread past the matte's edge.

Inputs

1. Sourcerequired

   The image to glow: a plate, a CG render or the whole comp, ideally in scene-linear colour.

2. Maskoptional

   Limits where the finished glow is blended in, by its alpha. It does not choose which lights glow; Glow Area does that.

3. Glow Areaoptional

   A matte, read from its alpha, that chooses which parts of the Source give off glow: white glows, black does not, grey glows less. Leave it unconnected to let the whole image glow.

Output. The Source with the glow added, by Add or Screen. View can also show the glow on its own (Glow Only) or the selected highlights before they spread (Highlights).

Quick start

1. Add ANR Glow after the image and connect it to Source.
2. Set View to Highlights and adjust Threshold and Soft Knee until only the lights you want are left. On display-referred images, whose highlights stay below 1, lower Threshold, for example to 0.7.
3. Set View back to Composite. Set the size of the halo with Radius and its brightness with Intensity.
4. Balance the core and the halo with Halo Spread: lower keeps the glow close to the lights, higher gives a wider, softer halo.
5. Shape the colour with Glow Saturation and Glow Tint, and for a lens look try Anamorphic, Horizontal Streaks or Color Dispersion.
6. To glow only some lights, roto them and connect the Roto to Glow Area.

The panel

The node's panel as Nuke shows it, with the values of a new node. Click any control to see what it does; tabs and sections work as in Nuke.

All controls

Tips

• Starting looks, with the other controls at their defaults: a natural bloom with Intensity 1.2, Radius 24 and Threshold 0.7; anamorphic lights with Radius 22, Anamorphic 0.85 and Horizontal Streaks 0.7; neon with Radius 32, Intensity 2.3, Color Dispersion 0.9 and Glow Saturation 1.5.
• To glow a matte, text or a logo, set Glow From to Alpha and Threshold to 0, then colour the glow with Glow Tint. The RGB can even be black.
• Saturated lights such as red tail lights have a low luminance and can stay below Threshold; Glow From: Brightest Channel picks them up.
• Glow Only gives the bloom by itself, to grade it separately or add it elsewhere in the comp with a plus Merge.
• Use Quality: Fast while you set the look and Balanced or High for the render. Small Radius values can take longer to render than large ones.
• On a CG element, before its Merge, the glow belongs to that element; on the finished comp, every light glows the same way. Either way, put it before ANR Film Grain so the grain stays crisp.

Good to know

• With Alpha: Preserve Source, the glow around an element has colour but no alpha. A Merge (over or plus) keeps it, but anything that multiplies by alpha, such as a Premult, removes it. Choose Include Glow when the glow must be in the alpha too.
• Glow Area reads alpha. A greyscale image with a solid alpha selects the whole frame, so copy the greyscale into alpha first. A connected matte that is black or empty means nothing glows.
• Expand Bounds lets the halo grow past the Source's bounding box; a crop to the format later in the comp can still cut it.
• Runs on the CPU: no GPU and no AI model needed.

Works with

ANR HalationAdds the warm red-orange fringe that film shows around bright lights and hot highlights.ANR DiffusionSoftens and blooms highlights like a diffusion filter on the lens, while texture and deep blacks stay intact.ANR Light RaysAdds shafts of light from the plate's highlights or a placed light: rays streaming from a centre, or beams aimed at a surface that stop on it, with fog and shadows.ANR Lens EffectsGives clean CG or a finished comp the character of a real lens: distortion, colour fringing, soft edges and a vignette, around one centre.