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Sample spread of rays when using cosine distribution. A value of 1.0 gives a perfect Lambertian distribution. Lower values shrink or "tighten" the effect along curves while larger amounts spread out the effect.

Bias

The bias will affect the falloff of the curvature and will be linear, decreasing with the distance from the shaded point. Bias can be used to take further samples into account more or less while nearby points have more weight.

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