Emissive Light

Emissive Light makes a face give off light when you bake. A ceiling panel, a screen or a strip light then lights the room around it in the colour of its texture. The light is baked into the lightmap, so the game shows it with no special support. See Which game plays what RED+ saves.

Where to find it

• Face Properties, in the Emissive Light group. Select faces in Texture mode (Shift+T) and choose Edit›, Properties... (Ctrl+P).
• View›, Show Emissive Ranges (RF+). The same command is in the RED+ menu.

How to use it

1. Select the faces in Texture mode and open Face Properties.
2. Tick Emits Light.
3. Set Bright and Depth. For a shaped beam, also set Width, Length or Angle.
4. Click the Color swatch if you want a colour other than the texture's own.
5. Click OK.
6. Choose Level›, Calculate Lighting (Shift+L).

Set these on faces of built geometry. On a brush you have just made, rebuild the geometry first (Space, see Rebuild Geometry): RED+ keeps face settings by the face's ID, which a face gets when the geometry is built, and settings made on a brush that has not been built yet can be lost.

Settings

The number fields take digits only. When you leave a field you have typed in, RED+ rounds the value to what OK stores and shows it: Bright and Depth to the nearest 10, and Width and Length up to an even number. Each value is also kept within its range, so a Depth of 200 becomes 150 and an Angle of 300 becomes 270. A 0 is left as it is.

Emits Light

The box has three states. Ticked turns the light on for every selected face. Cleared turns it off. Grey leaves each face as it is. While the box is cleared, the rest of the group is greyed out.

Bright

Bright scales the light the face gives off. It also sets how bright the face itself is baked: the face gets brighter up to 100 %, and higher values only add to the light it casts. 0 means 100 %.

Depth

Depth is how far the light reaches in front of the face. The light fades smoothly to nothing at that distance. 0 uses the level's emissive range, and the field then shows that range.

Width

Width sets how far the beam spreads sideways past the face: half the Width at each side. The beam is equally bright across its width and softens over up to 1.5 m at each side. 0 makes the beam round: the light reaches Depth in every direction in front of the face.

Length

Length gives the beam a second width, so the beam becomes a rectangle. Width runs along the face's longest edge and Length across it. A square ceiling panel then throws a square pool of light, and a strip light throws a strip.

Length works only together with Width. If you set Length on a face with no Width, RED+ sets Width to the same value, which gives a square beam. 0 keeps the beam round.

Angle

Angle is the full width of the cone of light, centred on the face's normal. At 180 the light fills the whole space in front of the face. A smaller Angle narrows it to a cone. An Angle over 180 also sends light behind the face, as far as the Depth: use it for a fixture that hangs in open space with a ceiling above it.

With Width set, only the part of the beam that is also inside the Angle is lit.

Color

The swatch shows the colour the face casts: its texture's average colour, or the colour you picked. Click the swatch to pick a colour. Reset goes back to the texture's own colour. A colour you pick also tints the face's own glow.

Default

Default sets Bright to 100, Depth to the level's emissive range, Width and Length to 0, Angle to 180 and the colour back to the texture's. Values you leave as Default set them are saved as defaults, so Depth keeps following the level's emissive range. Default does not change Emits Light.

Several faces at once

• A field that differs between the selected faces shows (mixed), and the Color swatch is blank.
• Click into a (mixed) field to clear it, then type a value for all the faces.
• A field you leave (mixed) or blank keeps each face's own value.
• OK changes only the fields you edited. Every other setting stays as it is on each face.

What the bake does

• The face gives off light from its whole area to the surfaces in front of it.
• Only the front of the face gives off light, unless Angle is over 180.
• Brushes and placed meshes between the face and a surface block the light, so it casts shadows.
• A larger face gives off more light. The output grows with the face's area, from 1x at 4 square metres up to 4x at 64 square metres and more.
• The face receives no light itself. Its own lightmap is filled at the brightness Bright sets, and a colour you pick also tints it.
• Emissive light is baked at every Quality tier, including Draft, and with Bounce % at 0.
• Relight Changed Lights skips it, and the log says scoped relight: bounce/emissive skipped. Surfaces it relights have no emissive light until the next full Calculate Lighting. Run a full Calculate Lighting to bake it.

Full Bright faces

A face that is both Full Bright and Emits Light gives off light too. The bake log lists each one as EMISSIVE (no lightmap surface, e.g. Full Bright). A Full Bright face has no lightmap of its own, so Bright changes only the light it casts, not the face.

Full Dark

Full Dark takes priority. A face with both is baked black and gives off no light.

Level-wide values

A level also has two emissive values of its own. Its emissive range is the reach of faces whose Depth is 0: 30 m on a new level. Its emissive strength scales all emissive light, including glowing liquids: 100 % on a new level. Level Properties has no fields for them.

In the editor

• In the viewports, an emissive face is drawn without its lightmap, at its texture's own brightness, like a Full Bright face. Its baked glow shows in game.
• Dynamic lights in the viewports do not change the brightness of an emissive face.

Show Emissive Ranges

View›, Show Emissive Ranges (RF+) draws a wireframe of each emissive face's beam in the viewports. The wireframe shows the beam's shape and direction but not its reach.

• When it is off, the wireframe shows only for selected faces that have Emits Light.
• When it is on, the menu item is ticked and the wireframe shows for every emissive face in the level, except on hidden brushes.
• The setting is saved with the level.
• The wireframe is drawn in the face's colour if you picked one, and in amber if not.
• A round beam draws as lines from the face's corners, leaning out at half the Angle from the face's normal, a line straight out from the centre, and a dimmer ring between them.
• A beam with Width draws as a box: the face's outline, widened by half the Width (and by half the Length across the face), pushed out from the face. The far end is bright and the outline at the face is dim. If Angle is not 180, the cone is drawn too.
• It also shows the glow of glowing liquids.

Good to know

• Bright and Depth stay as you set them when you rebuild geometry, bake or save. In a level saved by an older RED+ build, a rebuild may already have changed them: check them in Face Properties and set them again where needed.
• After loading a level and around each Rebuild Geometry, lines containing [RF+ FaceFlags] in the log say how many emitting faces there are, how many of their compiled copies do not carry the Bright and Depth set on the face, and how many RED+ put back.
• When you click OK, the log records Emits Light and every number in the group. During a bake it records each face that gives off light, with its colour, brightness and range.
• If the bake log says emitters exist but lit nothing, the emitting side faces away from the room, or nothing is within range and in line of sight of it.
• When RED+ opens a level that another editor has changed since RED+ saved it, it puts each face's settings back on its face, and drops settings whose face is gone. The log window says how many.
• Send the log with a problem report if a setting does not seem to take effect.