Tutorials · Light and Shadow · Chapter 5

A cone

15 minutes Uses: Light

By the end

A Cone light, sconce, on the top of the bay’s left column, aimed down at the floor
What Direction and Angle do, and the handles in the Viewport that set them
Why the wedge’s edge is soft

On this page

A light with a shape
Direction and Angle
What it costs
The sconce
Check it works

Reference

Light

A light with a shape

A Point light throws a circle. A Cone throws a wedge of that circle, which is what a sconce, a lamp with a shade or a torch held up in a doorway looks like. The hall has no sconce fixture, so this light hangs where one would: on the top of the bay’s left column, aimed down at the bay’s floor.

Select Hall, press + Add node, and choose Light. Rename it sconce.
Set its Position to 190 and 116: the top of the bay’s left column.
Set Kind to Cone.
Set Radius to 220, Intensity to 2.0 and Color to 1.0, 0.82, 0.6, alpha 1.
Set Direction to 0.26 and 0.966, and Angle to 0.6.
Press Ctrl+S.

The sconce selected, its Inspector narrowed to its Light: Enabled ticked, Kind Cone, Radius 220, Intensity 2.0, a warm Color, Direction x 0.26 and y 0.966, Angle 0.6, Sort Layer Default 0, Channel 0 and Softness 0, then the Sprite and Freeform groups; the Viewport draws a yellow wedge from the node at the top of the bay’s left column down to the floor, with a square handle on the arc, one near the node and one at the end of its left edge

The Light lists the settings of every kind, so the Sprite and Freeform groups at the bottom are there for chapters 7 and 8. A Cone ignores them. Radius, Intensity and Color mean what they did in chapter 2, and for a Cone the Radius is how far the wedge reaches along its Direction. Here it has to reach the floor, about 175 units below the sconce, so 200 to 300 looks right; at 120 the wedge dies on the wall.

The bay’s left column, the window and the floor under it: a pale wedge of light widens from the top of the column down and to the right, over the wall and the vines, its edges fading, the left pillar’s shadow at its foot — The sconce’s wedge, Angle `0.6`, the value you set.

In the Viewport a Cone is drawn as a yellow wedge from its node out to its Radius, with three square handles. The one on the arc sets the Radius, the one a short way out from the node aims the Direction, and the one at the end of the wedge’s left edge sets the Angle. Dragging them is quicker than typing, and the Inspector follows.

Direction and Angle

Kind Cone: Lights only a wedge of its circle. The wedge starts at the node and runs out to the Radius.
Direction: Which way the wedge points, as two numbers: across the screen, then down it. 0, 1 is straight down, and 0.26, 0.966 leans a little to the right of down. Only which way it points counts, not how long the two numbers are, and 0, 0 faces straight down. Aim it with the handle near the node rather than typing.
Angle: The wedge’s full width, in radians: 0.6 is about a third of a right angle, 1.57 a right angle and 3.14 half a circle. The field runs from 0 to 7. 0.3 to 1.2 looks right here: 0.3 is a torch’s beam and 1.2 a wide shade, and the chapter keeps 0.6. At 0, or below, it lights nothing.

The same stretch of the hall with the sconce at Angle 0.3: a thin wedge of light from the top of the column, hardly wider than the column — For comparison, Angle `0.3`.

The same stretch of the hall with the sconce at Angle 1.2: a wide fan of light from the top of the column over the wall, the vines and the floor — For comparison, Angle `1.2`.

The same stretch of the hall with the sconce aimed straight down: a wedge that is the same on both sides of the column, its middle line vertical — For comparison, Direction `0`, `1`: straight down the column.

What it costs

A Cone costs what a Point light does: one draw, and its shadows. Choose it for how it looks, not to save work.

The sconce

Every value of the light, to build it again in your own game.

Field	Value
Kind	Cone
Radius	`220`
Intensity	`2.0`
Color	`1.0`, `0.82`, `0.6`
Direction	`0.26`, `0.966`
Angle	`0.6`