Edit

Sky reflections

  • Article

In Azure Remote Rendering, a sky texture is used to light objects realistically. For augmented reality applications, this texture should resemble your real-world surroundings, to make objects appear convincing. This article describes how to change the sky texture. The sky only affects the rendering of PBR materials. Color materials and point clouds aren't affected.

Note

The sky texture is also referred to as an environment map. These terms are used interchangeably.

Object lighting

Azure Remote Rendering employs physically based rendering (PBR) for realistic lighting computations. Although you can add light sources to your scene, using a good sky texture has the greatest impact.

The images below show results of lighting different surfaces only with a sky texture:

Roughness 0 0.25 0.5 0.75 1
Non-Metal Dielectric, Roughness=0 Dielectric, Roughness=0.25 Dielectric, Roughness=0.5 Dielectric, Roughness=0.75 Dielectric, Roughness=1
Metal Metal, Roughness=0 Metal, Roughness=0.25 Metal, Roughness=0.5 Metal, Roughness=0.75 Metal, Roughness=1

For more information on the lighting model, see the materials chapter.

Important

Azure Remote Rendering uses the sky texture only for lighting models. It does not render the sky as a background, since Augmented Reality applications already have a proper background - the real world.

Changing the sky texture

To change the environment map, all you need to do is load a texture and change the session's SkyReflectionSettings:

async void ChangeEnvironmentMap(RenderingSession session)
{
    try
    {
        Texture skyTex = await session.Connection.LoadTextureFromSasAsync(new LoadTextureFromSasOptions("builtin://VeniceSunset", TextureType.CubeMap));
        session.Connection.SkyReflectionSettings.SkyReflectionTexture = skyTex;
    }
    catch (RRException exception)
    {
        System.Console.WriteLine($"Setting sky reflection failed: {exception.Message}");
    }
}

void ChangeEnvironmentMap(ApiHandle<RenderingSession> session)
{
    LoadTextureFromSasOptions params;
    params.TextureType = TextureType::CubeMap;
    params.TextureUri = "builtin://VeniceSunset";
    session->Connection()->LoadTextureFromSasAsync(params, [&](Status status, ApiHandle<Texture> res) {
        if (status == Status::OK)
        {
            ApiHandle<SkyReflectionSettings> settings = session->Connection()->GetSkyReflectionSettings();
            settings->SetSkyReflectionTexture(res);
        }
        else
        {
            printf("Texture loading failed!\n");
        }
    });
}

The LoadTextureFromSasAsync variant is used above because a built-in texture is loaded. When loading from linked blob storages instead, use the LoadTextureAsync variant.

Sky texture types

You can use both cubemaps and 2D textures as environment maps.

All textures have to be in a supported texture format. You don't need to provide mipmaps for sky textures.

Cube environment maps

For reference, here's an unwrapped cubemap:

An unwrapped cubemap

Use RenderingSession.Connection.LoadTextureAsync/ LoadTextureFromSasAsync with TextureType.CubeMap to load cubemap textures.

Sphere environment maps

When using a 2D texture as an environment map, the image has to be in spherical coordinate space.

A sky image in spherical coordinates

Use RenderingSession.Connection.LoadTextureAsync with TextureType.Texture2D to load spherical environment maps.

Built-in environment maps

Azure Remote Rendering provides a few built-in environment maps that are always available. All built-in environment maps are cubemaps.

Identifier Description Illustration
builtin://Autoshop Variety of stripe lights, bright indoor base lighting Autoshop skybox used to light an object
builtin://BoilerRoom Bright indoor light setting, multiple window lights BoilerRoom skybox used to light an object
builtin://ColorfulStudio Varyingly colored lights in medium light indoor setting ColorfulStudio skybox used to light an object
builtin://Hangar Moderately bright ambient hall light SmallHangar skybox used to light an object
builtin://IndustrialPipeAndValve Dim indoor setting with light-dark contrast IndustrialPipeAndValve skybox used to light an object
builtin://Lebombo Daytime ambient room light, bright window area light Lebombo skybox used to light an object
builtin://SataraNight Dark night sky and ground with many surrounding lights SataraNight skybox used to light an object
builtin://SunnyVondelpark Bright sunlight and shadow contrast SunnyVondelpark skybox used to light an object
builtin://Syferfontein Clear sky light with moderate ground lighting Syferfontein skybox used to light an object
builtin://TearsOfSteelBridge Moderately varying sun and shade TearsOfSteelBridge skybox used to light an object
builtin://VeniceSunset Evening sunset light approaching dusk VeniceSunset skybox used to light an object
builtin://WhippleCreekRegionalPark Bright, lush-green, and white light tones, dimmed ground WhippleCreekRegionalPark skybox used to light an object
builtin://WinterRiver Daytime with bright ambient ground light WinterRiver skybox used to light an object
builtin://DefaultSky Same as TearsOfSteelBridge DefaultSky skybox used to light an object

API documentation

Next steps