Light is a well-studied and predictable phenomenon; because of this, software products are able to emulate the properties of a photograph. Despite the physically complex nature of light as wave/particle, for the purposes of software rendering we treat light as though it were a myriad tiny particles bouncing around. Some are absorbed, others are reflected directly (as in a mirror) or distributively (as though off rubber). Such particles (photons), however, often travel long distances, all the while bouncing off several services, making their simulation particularly difficult and requiring extensive computing.
Enscape has a unique method of calculating bounced light and reflections in realtime with no precalculation required, independant from the scene size. For a slower computer, however, it is possible to disable this feature to increase performance. You’ll see that the complex subtleties of lighting are lost.
Open the settings window and check the box Global Illumination. If you enable it, it will also affect the exported Standalone version.
The simplest way to reduce the grain is to increase the rendering enhancement cycles in the settings. This may take some time, and won’t have any effect on Enscape while you are moving. However, you have other options:
Enscape calculates the lighting conditions for rooms and representative spots in your project. While this may cause round spots, you can avoid them by decreasing the total volume of your project. Note that this does not mean you have to reduce the project’s complexity, just its volume. For example, if you have multiple buildings in one project, try hiding all but the one you intend to see or display.