Image Based Lighting

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Image based lighting (IBL) lights PBR materials with an HDR image of the surroundings. A Skybox can then draw that same image behind the scene.

Environment Map

Loads an equirectangular .hdr image and bakes it into an EnvironmentMap.

val environmentMap =
    EnvironmentMap(device, resourcesVfs["hdri/sky.hdr"].readHdrImage())

Environment

Passes the environment map to a PBREnvironment. The intensity scales the image based lighting.

val environment = PBREnvironment(device, environmentMap = environmentMap)
environmentMap.intensity = 1.5f

Skybox

Creates a Skybox with the same color and depth formats as the ModelBatch. A higher lod blurs the sky.

val skybox = Skybox(device, environmentMap, hdrFormat, depthFormat)
skybox.lod = 2f
skybox.intensity = 0.8f

Rendering

Render the skybox in the same render pass, after the scene.

onUpdate { dt ->
    val renderPass = ... // main render pass
    models.forEach { modelBatch.render(it, camera, environment) }
    modelBatch.flush(renderPass, camera, dt)
    skybox.render(renderPass, camera)
    renderPass.end()
}

onRelease {
    skybox.release()
    environmentMap.release()
}

HDR

The environment is brighter than 1.0, so it pairs best with HDR and Tonemapping.

val hdrFormat = TextureFormat.RGBA16_FLOAT
val modelBatch =
    ModelBatch(device).apply {
        addPipelineProvider(PBRMaterialPipelineProvider())
        colorFormat = hdrFormat
    }
val skybox = Skybox(device, environmentMap, hdrFormat)
val tonemapper = Tonemapper(device, graphics.preferredFormat)

PREVIOUSHDR and Tonemapping

NEXTBloom