Deferred rendering pipeline

Korender supports deferred rendering pipeline as an experimental feature.

Deferred rendering is a technique where geometry and material data are rendered first into multiple textures called the G-buffer. Lighting is then calculated in a separate pass using this stored data, allowing efficient handling of many dynamic lights. This approach enhances performance in complex scenes and enables various screen-space effects.

To switch to deferred rendering, add DeferredShading to the Frame context:

Frame {
    DeferredShading()
}

Shading material modifiers

Additional material modifiers applied during the shading pass:

Frame {
    val cubeMap = ...
    DeferredShading {
        Shading {
            env = cubeSky(cubeMap)
        }
    }
}

Shading(block: ShadingMaterialScope.() -> Unit) — the block configures shading material with var env: SkyMaterial? for environment mapping.

Screen-space reflections

Frame {
    DeferredShading {
        Ssr(downsample = 2, envTexture = cubeMap)
    }
}

Ssr(downsample, maxReflectionDistance, linearSteps, binarySteps, lastStepRatio, envTexture) — traces reflected rays in screen space.

Parameter	Type	Default	Description
downsample	Int	2	Downsample factor for SSR framebuffer (1, 2, or 4)
maxReflectionDistance	Float	10f	Maximum distance a reflected ray is traced
linearSteps	Int	64	Number of forward raytracing steps
binarySteps	Int	5	Number of binary search steps after forward tracing
lastStepRatio	Float	4f	Factor to multiply forward step at max distance
envTexture	CubeTextureDeclaration?	null	Environment map fallback for off-screen reflections

Bloom

Frame {
    DeferredShading {
        Bloom(amount = 3.0f)
    }
}

Bloom(threshold, amount, radius, downsample) — standard bloom.

Parameter	Type	Default	Description
threshold	Float	0.9f	Luminance threshold for glowing pixels
amount	Float	3.0f	Bloom intensity
radius	Float	16f	Bloom radius
downsample	Int	2	Downsample factor

BloomWide(threshold, amount, downsample, mips, offset, highResolutionRatio) — Kawase blur bloom variant for wider glow.

Screen-space ambient occlusion

Frame {
    DeferredShading {
        Ssao(blurRadius = 10f)
    }
}

Ssao(downsample, sampleCount, radius, bias, intensity, blurRadius) — standard SSAO.

Hbao(downsample, sampleCount, radius, bias, intensity, blurRadius) — horizon-based ambient occlusion (HBAO).

Decals

Frame {
    DeferredShading {
        Decal(
            material = decal {
                colorTexture = texture("textures/decal.png")
                metallicFactor = 0.2f
            },
            position = pos,
            look = look,
            up = up,
            size = 1.6f
        )
    }
}

Decal(material: DecalMaterial, position: Vec3, look: Vec3, up: Vec3, size: Float) — projects a decal onto scene geometry.