The Water Material is used to set a surface to look like water. The look applies primarily to the surface only for when the camera is above water level.

That is, it is not a full volumetric effect, such as Volumetric Fog, for above and below the surface (however, see Rasterization).  However, there is an under water look that can be rendered.

You can use the Water Material for both rendering pipelines - Ray Tracing and Rasterization.

1.1: Ray Tracing

For Lumion 2025.0, the Water Material has been fully converted to the Ray Trace rendering pipeline. See Section: 8.1: Changes from Prior versions.

This provides enhanced realism and improved integration with reflections, refractions and global illumination. 

It is also important top understand what you see for different Modes and Preview states.

See further below in Section: 6. Using the Ray Trace Effect setting.

There are some current limitations on the implementation.  See Section 7.2: Known issues.

1.2: Rasterization

Where you are choosing to use the Rasterization rendering pipeline, then the same Material and properties are available.

The differences will be in how this rendering type affects the look of the output.

See Section 7. Water Materials for the Rasterization rendering pipeline.

1.3: Other Changes:

There are some changes for some Properties for those used to using prior versions.  See Section: 7.1.1: Material Property Changes.

2.1: Render surfaces such as swimming pools:

2.2: Render other surfaces such as lakes. rivers and even large water areas where the Ocean is not needed:

• Knowledge Base: How do you use the Material Editor in Lumion 2023 and newer?

3.1: New Material for Water

Click on the New tab for a New Material:

3.2: Imported as Water Material or Existing Water Material:

In some cases the Material Type will be auto-created as Water for you when importing:

• Knowledge Base:  How do Auto-Converted Materials work in Lumion?

Select the surface then the Settings tab.

Or, double-clock to open the Settings tab.

Edit the Water Material settings/properties as below in section 4.

No options are available for loading your own Maps to any of the settings (as in the Glass or Standard Materials).  All control over the look is via the sliders and internally generated water system only.

4.1: Color

Color Palette only (no slider, there is no texture for mixing to a color)

4.2: Wave Height

New Water Material Default value: 24%.

4.3: Wave Scale

New Water Material Default value: 78%.

Requirements of the Height and Scale would differ from a swimming pool to a river to a lake and to an area/surface used for an alternative to the Ocean.

4.4: Caustics Scale

New Water Material Default value: 14%.

See section 7.2.2: Caustics Property.

Caustics are the result of light passing through a body with transparent volume, in this case water, at the surface and resulting in possible refraction of the light.  If there are waves, then the light is refracted at different angles.  When animated, you see the motion of light on the side or bottom surfaces  For example a swimming pool, the ripples in the water bend and focus the light, forming shimmering, dynamic patterns.

In Build Mode:

4.5: Reflectivity

New Water Material Default value: 39%.

The amount that the Water surface is reflective - from 0 to a normal level of 39% to 100%.  Above 100% to 200% the Reflections are over rendered to give up to a mirror like surface, similar to the Glass Material:

• Knowledge Base:  The New Glass Material for Lumion 2024 and the Glass setting for Ray Tracing

HQ Preview (High Quality) is required.  See Section 6.2.2: Important Render Rules for Water - Performance Management in topic 6. Using the Ray Trace Effect setting.

A close up view of the window looking into the lounge:- notice the reflections and refractions of the water:

Rendered:

4.6: Lightup Water Color

New Water Material Default value: 29%.

Lightens the look of the water for the same Color.

At minimum percentage of 0%:

Rendered

At maximum percentage of 100%:

Rendered:

4.7: Roughness

New Water Material Default value: 0%.

Roughness, as in a Standard Material for PBR materials, will absorb more light/prevent less reflections the more the surface is rough.

The result as in the example of 100% Roughness below, is to make the surface less transparent and more cloudy.

At the minimum of roughness - very smooth then:

4.8: Foam

New Water Material Default value: 0%.

See section 7.2.3: Foam Property.:

The Library provides for 20 pre-made materials you can use for quicker setup of any water material surfaces.

6.1: The Fully Ray Traced Glass and Water setting

To render Water as Ray Traced water, set the Fully Ray Traced Glass and Water button to On.

This rendering setting, as with the Glass Material will control and Ray Trace render all surfaces with a Water Material.

One quick setting, in one place.

When the setting is On:

All surfaces in the Ray Trace rendering pipeline will have reflections of the Water surface and the water surface will receive those surfaces reflections.

6.2: Important change for Lumion 2024 Projects:

Enabling the Ray Tracing for the Water Material will also require enabling Fully Ray Traced Glass.

Doing so may have some impact on the rendered look of the glass if Fully Ray Traced Glass was not required.  For example you wanted to use the Standard Glass for Planar windows.

6.2.1: For Lumion 2024 users and Projects

In Lumion 2024 you could use the Standard Ray Traced Glass for planar based surfaces such as window panes.  The Standard Ray Traced Glass setting occurred when the Fully Ray Traced Glass setting was Off.

Fully Ray Traced Glass (On) was only needed for full complex curve based glass, and not for planar glass.  And we also recommended using Standard Glass for planar windows, although some users did also use the Fully Ray Traced Glass option, and found the results were OK.

Impact.  All Glass surfaces including planar windows will be rendered for all properties of the advanced Fully Ray traced system.  The rendering process does have an impact on rendering times as it is much more complex and sometimes the look might be different, depending on the lighting.

For planar window based glass:  you only need to use Fully Ray Traced Glass and Water setting when the camera view takes in a Scene where the water is to be reflected in the windows. 

If that is not the case then you can set the Fully Ray Traced Glass and Water to Off.  The water will still receive reflections under Ray Tracing, the same as for Glass (Standard)

• Knowledge Base:  The New Glass Material for Lumion 2024 and the Glass setting for Ray Tracing

6.2.2: Important Render Rules for Water - Performance Management

When enabled, Fully Ray Traced Glass and Water will only be rendered in HQ Preview and for final output. In real-time Preview, non-Ray Traced versions are used.

This is a required measure for performance reasons. 

Impact:  you do not see the reflections of the water surface on other reflective surfaces such as a Glass Material for windows.

Using Build Mode to set the look of the Water:

Uses the Rasterization renderer.  You may need to check the look of the water in a Photo or Clip using HQ Preview.

Using Build With Effects Mode to set the look of the Water:

Build With Effects Mode uses a default fixed setting of 1 Ray Trace Sample, when the Ray Tracing effect is On.

If the Effect is On or Off, the render is the same as for HQ Preview Off - no reflections of a water surface.

Photo, Movie or Panorama Modes - Previews:

If you have Setting On for Auto Update Preview:

Or you activate an HQ Preview by clicking on the Preview screen then Water will be rendered as Fully Ray Traced.

Use the HQ Preview option to do finalization of the look.

Usually in Movie Mode when you use the scrub-bar or Playback button the Preview is not in HQ Preview.

When the setting is Off:

The look will be from the Rasterization renderer.

When you chose to use the Rasterization rendering pipeline (Ray Tracing Effect is Off) the same Water Material and its properties are used.

Add an Effect Stack for Rasterization from the Styles or set up your own set of Effects.

Add a Planar Reflection to  the water surface for highest quality reflections.  

• Knowledge Base:  How do Planar Reflections work?

8.1: Changes from Prior versions:

All versions prior to Lumion 2025.0 use the Rasterization rendering pipeline.

Lumion 2023 and 2024 also used a fallback to the Rasterization rendering pipeline even though the Ray Trace Effect was On/enabled.  This was done to allow for future implementation as in Lumion 2025 of fully integrating the Water Material into the Ray Trace rendering pipeline.

Lumion 2023 and 2024 merged the results of the rendering but certain elements such as reflections for a water surface on a Glass Material were absent.

As noted earlier (Section 1.1: Ray Tracing), these limitations no longer exist as the Water Material is now fully Converted to the Ray Trace rendering pipeline. 

To enable this feature, select the Fully Ray Traced Glass and Water setting in the Ray Trace Effect

(similar to how full Ray Traced Glass was enabled in Lumion 2024)

See further on using this setting in Section: 6. Using the Ray Trace Effect setting.

8.1.1: Key benefits:

You will now see the Water Material surface in Ray Traced reflections.

Reflections on the surface of the water are now fully from Ray Tracing.

Fully Ray Traced water.  Notice the accurate reflections and refractions and visibility in other reflective surfaces.

8.1.2: Material Property Changes

Two properties are no longer used:  Water Density and Border Displacement, example Lumion 2024.4.3.

The order of the properties has changed slightly.

8.1.3: Results and Setting Up the Scene with the new Water Material

Apply the Water Material and set the required level of Reflectivity.

It is now easy to get reflections on the water surface. No need for adding a special surface to get reflections:

It is now easy to see reflections of Nature Objects (from 2024.X):

• Knowledge Base:  Changes for Projects to use the Water Material in Lumion 2023?

8.2: Known issues

8.2.1: Water is currently implemented for:

Fully Ray Traced water currently applies only to the water material. Water planes, the ocean, and the waterfall material are not yet raytraced but are planned for a future release.

8.2.2: Caustics Property:

The Caustics property in the water material is not yet functional with Ray Traced water.  (version 2025.0)

8.2.3: Foam Property:

The Foam property in the water material is not yet functional with Ray Traced water.  (version 2025.0)

8.2.4: Underwater Effect:
The underwater effect may or may not work as expected when Fully Ray Traced water is enabled.

Example: you may see something like this:

With Ray Tracing:

For Fully Ray Traced Glass and Water:

Here it is working OK (Example Project: Villa Cabrera):

8.2.5:  Orthographic view:

For the Rasterization rendering pipeline the water is not visible in the Orthographic view.

For Ray Tracing it is working OK.

8.2.6:  Some decreased accuracy:

For the Rasterization rendering pipeline, there can be decreased accuracy—particularly between two surfaces due to camera distance.  This  can cause Z-bias issues in water materials, potentially resulting in black rendering artifacts.

This is similar to when you have a model very far from world center.