# Lights

**Incari** has two types of **Light Objects**: the **Spot Light** and the **Point Light**.

The **Point** **Light** is *omnidirectional*, meaning that light is emitted equally in all directions; while the **Spot Light** is *directional* and will only light the area that it is rotated towards. Additionally, unlike **Point Light**, **Spot Light** supports shadow mapping and has an extra set of **Attributes** for that purpose.

| Attribute        | Spot Light | Point Light |
| ---------------- | ---------- | ----------- |
| `Color`          | ✔          | ✔           |
| `Brightness`     | ✔          | ✔           |
| `Attenuation`    | ✔          | ✔           |
| `Radial Falloff` | ✔          | ✘           |

## Light

### Color

`Color` determines the color of the light being emitted.

Please note that the `Color` **Attribute's** *brightness* level will affect the brightness of the light itself. It is recommended that you always have the brightness level set to 1 and use the actual `Brightness` **Attribute** to alter the intensity of the light.

`Color's` *alpha* level has no effect.

### Brightness

`Brightness` governs the intensity of the light, with lower values giving less intense light emission and vice versa.

![](https://3009747178-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-MIspkFTPkuGkv4UgQGs-1330240639%2Fuploads%2Fgit-blob-fbc9b65fb6bd58e9280b9ff437e62769a63797a5%2Fbrightness.gif?alt=media)

### Attenuation

`Attenuation` relates to the spread, or reach, of the light. Lower levels only illuminate close **Objects**, whereas high levels allow the light to reach **Objects** that are further away.

![](https://3009747178-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-MIspkFTPkuGkv4UgQGs-1330240639%2Fuploads%2Fgit-blob-bf2f6502a1ca94b00cfb53b9eb061e46a1546e21%2Fattenuation.gif?alt=media)

### Radial Falloff

`Radial Falloff` is used to change the smoothness of the light falloff. Lower levels will give a smoother transition between light and dark areas, but will be darker overall. Higher levels give a more contrasting light-to-dark transition and will appear comparatively brighter.

This **Attribute** is only available on the **Spot Light Object**.

![](https://3009747178-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-MIspkFTPkuGkv4UgQGs-1330240639%2Fuploads%2Fgit-blob-29d43cc50d7e4c99222a3685fa1ad292f6fc77fc%2Fradialfalloff.gif?alt=media)

## Shadow Mapping

**Shadow Mapping** is a performant method of approximating shadows in real-time. Without getting too technical, **Shadow Mapping** takes the depth and normal passes of the **Scene** from the perspective of the **Spot Light**, calculates which areas are occluded, and projects the shadow map onto the **Scene**.

There is no 'one size fits all' setup for **Shadow Mapping**. It is invariably a matter of tweaking and adjusting to achieve the desired visual result for your **Scene**, as well as meeting the *performance* requirements of your **Project**.

### Enable

**Shadow Mapping** can be turned off/on using the `Enable` switch. Whether or not you use this effect often comes down to performance. If you are having performance issues, then you should consider removing the effect, or adjusting the other settings.

### Resolution

`Resolution` alters the size of the shadow map. Just like with normal *2D* textures, higher resolutions produce better quality, at the cost of increasing processing time and file size.

![](https://3009747178-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-MIspkFTPkuGkv4UgQGs-1330240639%2Fuploads%2Fgit-blob-8e56475f49df8521440a37991600ab81091331eb%2Fresolution.gif?alt=media)

### Kernel Size

`Kernel Size` relates to the size of each sampled area during the calculation. It is a fairly complex subject, but it basically affects the smoothness of the shadow map. Lower levels give crisp, but jagged, shadows; higher levels give smoother, but less defined results.

Increased `Kernel Size` may help improve results that suffer from *shadow acne* or reduce artifacts in cases where the shadow map `Resolution` is low.

![](https://3009747178-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-MIspkFTPkuGkv4UgQGs-1330240639%2Fuploads%2Fgit-blob-63bebe8ba019a63152e6baed99fc18750528df54%2Fkernel-size.gif?alt=media)

### Clip Near

As stated above, **Shadow Mapping** takes passes from the **Light's** perspective. Like the `Clip Near` **Attribute** of **Camera**, everything within the defined distance isn't rendered and is therefore excluded from those passes and the **Shadow Mapping** algorithm.

![](https://3009747178-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-MIspkFTPkuGkv4UgQGs-1330240639%2Fuploads%2Fgit-blob-6e987fed7885a575a2e16e05b7e9ae89cd940a2d%2Fclip-near.gif?alt=media)

### Offset

`Offset` offsets the depth of the shadow map and can massively improve its appearance by reducing *shadow acne*. It is recommended that you increase this value by very small increments (0.0001), until you get an acceptable reduction in artifacts.

Due to the effect `Offset` has on the **Shadow Mapping** algorithm, higher values can cause shadows to appear to become disconnected from the geometry that casts them.

![](https://3009747178-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-MIspkFTPkuGkv4UgQGs-1330240639%2Fuploads%2Fgit-blob-f0689762a823470433d502229b779ed7871a8ff0%2Foffset.gif?alt=media)