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// Copyright 2009 Intel Corporation
// SPDX-License-Identifier: Apache-2.0
#pragma once
#include "rkcommon/math/math.ih"
OSPRAY_BEGIN_ISPC_NAMESPACE
inline float roughnessToAlpha(float roughness)
{
// Roughness is squared for perceptual reasons
return max(sqr(roughness), 0.001f);
}
// [Burley, 2012, "Physically Based Shading at Disney", Course Notes, v3]
inline vec2f roughnessToAlpha(float roughness, float anisotropy)
{
float aspect = sqrt(1.f - 0.9f * anisotropy);
return make_vec2f(max(sqr(roughness) / aspect, 0.001f),
max(sqr(roughness) * aspect, 0.001f));
}
OSPRAY_END_ISPC_NAMESPACE
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