Here's how:

1.  When using the Ray Tracing Effect:

If you add the Ray Tracing Effect in Photo, Movie or Panorama Modes, Lumion uses photo-realistic ray tracing which automatically includes rendering of reflections.

The Reflection Effect that includes options for SpeedRay Reflections and/or Planar Reflections is automatically disabled.

You do not need to set the sliders for the settings or assign surfaces for the Planar Reflections. 

However, you may want to produce renderings not using Ray Tracing but the Lumion general rasterization rendering pipeline for either production, or for performance reasons, or for preview, or review.  If so, you will need to follow the guides in Section 2 (below) General Rendering Pipeline.

2. General Rendering Pipeline(Rasterization):

There are three different reflection types:

• Projected Reflections: Not very accurate on any surface but renders very fast.
• SpeedRay Reflections (Lumion Pro only): Mostly accurate on any surface & renders fast.
• Planar Reflections: Very accurate on planar surfaces but renders slowly.

Projected Reflections are the default reflection type in Lumion. They are assigned to reflective surfaces that are not affected by Planar Reflections and SpeedRay Reflections.

The Projected Reflection method is only an approximation and will never provide as realistic reflections as Planar Reflections or SpeedRay Reflections but they are very fast to render.

Projected Reflections in Lumion rely on a single 360 degree panoramic reflection texture which is projected onto any reflective materials, including the Ocean, that are not using Planar Reflections or SpeedRay Reflections. The position that the 360 degree panoramic reflection texture is rendered at is defined by the Reflection Control object.

In Build Mode, the Reflection Control object is placed 100m above the Lumion Terrain in order to provide generic reflections of the sky and entire Scene.

However, when you render Photos in Photo or Movie modes, the Reflection Control object is automatically placed at the camera position.

When you render Clips or Movies, the Reflection Control object is placed at the position of the camera at the first frame of each Clip. The position of the Reflection Control object does not change while the Clip is being rendered.

To preview the reflections before starting the rendering procedure, you can press the U key to update the Projected Reflections so that they're rendered at the current camera position.

To disable these automated functions, you can place the Reflection Control object in your Scene in Build Mode, and move it around or animate it in Movie Mode with the Move or Advanced Move Effects.

TIPS:

• Move the Reflection Control high up in the sky (say 500m) to get reflections only of the clouds and the sky. This can work to avoid some pixelated looking reflections.
• If you have added a Reflection Control for a Movie, you will need to set the position for each Clip by assigning a Move or Advanced Move Effects to each Clip. However, it is not always required that you move the Reflection Control along with the camera. That is, sometimes it is enough to simply set a single position for each Clip.
• Interior views require the Reflection Control to be within the interior area. Generally position it high up away from other objects, so that you get brighter general reflections and not specific objects included in the reflection.

See also:

• Knowledge Base: How do SpeedRay Reflections work?
• Knowledge Base: How do Planar Reflections work?