---
title: "First Steps"
url: "https://help.maxon.net/c4d/en-us/Content/html/32222.html"
section_path: "Render Menu > Render Setting > Global Illumination > First Steps"
description: "What should you do if you want to light a scene using Global Illumination? Which workflow leads me quickly to the best results?"
---

# First Steps

What should you do if you want to light a scene using Global Illumination? Which workflow leads me quickly to the best results?

1. Activate Global Illumination in the Render Settings ("Effects … " button).
2. Set [Preset](https://help.maxon.net/c4d/en-us/Content/html/VPGISETUP-GI_GROUP_GENERAL.html.md) to an appropriate setting. Any subsequent test renderings must be done at a reasonable rate of speed. Otherwise the test render phase could turn into an arduous process. Follow these steps to make sure this does not happen:
   - Render at lower [resolutions](https://help.maxon.net/c4d/en-us/Content/html/DRENDERSETTINGS-RDATA_GROUP_OUTPUT.html.md) (e.g., 320 x 240 is often sufficient to check the brightness of a scene or part of a scene) or:
   - Use the [Interactive Render Region](https://help.maxon.net/c4d/en-us/Content/html/OSNIPER.html.md) (IRR) at a lower resolution.
3. First, concentrate on the brightness, light dispersion and similar elements.\
   Determine if you need additional light sources. The [Gamma](https://help.maxon.net/c4d/en-us/Content/html/VPGISETUP-GI_GROUP_GENERAL.html.md) value (**General** tab) can be increased, if necessary (keep in mind also the Color Mapping parameter [here](https://help.maxon.net/c4d/en-us/Content/html/VPCOLORMAPPING-ID_VIDEOPOSTPROPERTIES.html.md) and [here](https://help.maxon.net/c4d/en-us/Content/html/32220.html.md)).
4. Once you are satisfied with the lighting of your scene you can turn your attention to the GI quality. First, check to see if you can implement [Portals](https://help.maxon.net/c4d/en-us/Content/html/32221.html.md) or Polygon/Area Lights. This can improve the render quality and shorten the render time enormously.
5. Now begin increasing the GI quality by defining a higher quality Preset - or by adjusting individual settings.

# Error Correction

## GI shadows not rendered precisely enough?

For Portals and Polygon Lights activate the [Force Per-Pixel](https://help.maxon.net/c4d/en-us/Content/html/VPGISETUP-GI_GROUP_GENERAL.html.md) option.

## Spotty renderings?

In most cases, raising the [Samples](https://help.maxon.net/c4d/en-us/Content/html/VPGISETUP-GI_GROUP_GENERAL.html.md) value (**General** tab) will help.

## Rendering takes too long?

Are the [Samples](https://help.maxon.net/c4d/en-us/Content/html/VPGISETUP-GI_GROUP_GENERAL.html.md), [Records Density](https://help.maxon.net/c4d/en-us/Content/html/VPGISETUP-GI_GROUP_IRRADIANCE.html.md) or values too high? Is one or more of the following activated (these options improve image quality but slow rendering): [Distance map](https://help.maxon.net/c4d/en-us/Content/html/VPGISETUP-GI_GROUP_IRRADIANCE.html.md) for Polygon Lights/Portals activated? [Refractive Caustics](https://help.maxon.net/c4d/en-us/Content/html/VPGISETUP-GI_GROUP_OPTIONS.html.md) activated (**Options** tab)?

Have you activated [Primary Method](https://help.maxon.net/c4d/en-us/Content/html/VPGISETUP-GI_GROUP_GENERAL.html.md) and [Secondary Method](https://help.maxon.net/c4d/en-us/Content/html/VPGISETUP-GI_GROUP_GENERAL.html.md) QMC modes? 2 times QMC produces the best quality but is by far the slowest GI mode.

Are the values for [Samples](https://help.maxon.net/c4d/en-us/Content/html/VPGISETUP-GI_GROUP_GENERAL.html.md) or [Record Density](https://help.maxon.net/c4d/en-us/Content/html/VPGISETUP-GI_GROUP_IC2.html.md) too high? Is [Force Per-Pixel](https://help.maxon.net/c4d/en-us/Content/html/VPGISETUP-GI_GROUP_GENERAL.html.md) enabled for polygon lights/portals? Check your [Refractive Caustics](https://help.maxon.net/c4d/en-us/Content/html/VPGISETUP-GI_GROUP_OPTIONS.html.md) settings.

Maybe you've enabled the saving and loading of overly large radiosity maps (**Cache** tab).

Unfortunately there are innumerable more reasons for slow rendering.