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Cycles: fix nan's generated by glossy BSDF in some cases.

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This commit is contained in:
Brecht Van Lommel 2012-04-06 16:08:14 +00:00
parent f349aeacf1
commit f7a0499f16
1 changed files with 25 additions and 20 deletions
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45
intern/cycles/kernel/svm/bsdf_microfacet.h
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@ -43,6 +43,11 @@ typedef struct BsdfMicrofacetGGXClosure {
float m_eta;
} BsdfMicrofacetGGXClosure;
__device_inline float safe_sqrtf(float f)
{
return sqrtf(max(f, 0.0f));
}
__device void bsdf_microfacet_ggx_setup(ShaderData *sd, ShaderClosure *sc, float ag, float eta, bool refractive)
{
float m_ag = clamp(ag, 1e-4f, 1.0f);
@ -88,8 +93,8 @@ __device float3 bsdf_microfacet_ggx_eval_reflect(const ShaderData *sd, const Sha
float cosThetaM4 = cosThetaM2 * cosThetaM2;
float D = alpha2 / (M_PI_F * cosThetaM4 * (alpha2 + tanThetaM2) * (alpha2 + tanThetaM2));
// eq. 34: now calculate G1(i,m) and G1(o,m)
float G1o = 2 / (1 + sqrtf(1 + alpha2 * (1 - cosNO * cosNO) / (cosNO * cosNO)));
float G1i = 2 / (1 + sqrtf(1 + alpha2 * (1 - cosNI * cosNI) / (cosNI * cosNI)));
float G1o = 2 / (1 + safe_sqrtf(1 + alpha2 * (1 - cosNO * cosNO) / (cosNO * cosNO)));
float G1i = 2 / (1 + safe_sqrtf(1 + alpha2 * (1 - cosNI * cosNI) / (cosNI * cosNI)));
float G = G1o * G1i;
float out = (G * D) * 0.25f / cosNO;
// eq. 24
@ -129,8 +134,8 @@ __device float3 bsdf_microfacet_ggx_eval_transmit(const ShaderData *sd, const Sh
float cosThetaM4 = cosThetaM2 * cosThetaM2;
float D = alpha2 / (M_PI_F * cosThetaM4 * (alpha2 + tanThetaM2) * (alpha2 + tanThetaM2));
// eq. 34: now calculate G1(i,m) and G1(o,m)
float G1o = 2 / (1 + sqrtf(1 + alpha2 * (1 - cosNO * cosNO) / (cosNO * cosNO)));
float G1i = 2 / (1 + sqrtf(1 + alpha2 * (1 - cosNI * cosNI) / (cosNI * cosNI)));
float G1o = 2 / (1 + safe_sqrtf(1 + alpha2 * (1 - cosNO * cosNO) / (cosNO * cosNO)));
float G1i = 2 / (1 + safe_sqrtf(1 + alpha2 * (1 - cosNI * cosNI) / (cosNI * cosNI)));
float G = G1o * G1i;
// probability
float invHt2 = 1 / dot(ht, ht);
@ -161,8 +166,8 @@ __device int bsdf_microfacet_ggx_sample(const ShaderData *sd, const ShaderClosur
//tttt and sin(atan(x)) == x/sqrt(1+x^2)
float alpha2 = m_ag * m_ag;
float tanThetaM2 = alpha2 * randu / (1 - randu);
float cosThetaM = 1 / sqrtf(1 + tanThetaM2);
float sinThetaM = cosThetaM * sqrtf(tanThetaM2);
float cosThetaM = 1 / safe_sqrtf(1 + tanThetaM2);
float sinThetaM = cosThetaM * safe_sqrtf(tanThetaM2);
float phiM = 2 * M_PI_F * randv;
float3 m = (cosf(phiM) * sinThetaM) * X +
(sinf(phiM) * sinThetaM) * Y +
@ -187,8 +192,8 @@ __device int bsdf_microfacet_ggx_sample(const ShaderData *sd, const ShaderClosur
// eval BRDF*cosNI
float cosNI = dot(m_N, *omega_in);
// eq. 34: now calculate G1(i,m) and G1(o,m)
float G1o = 2 / (1 + sqrtf(1 + alpha2 * (1 - cosNO * cosNO) / (cosNO * cosNO)));
float G1i = 2 / (1 + sqrtf(1 + alpha2 * (1 - cosNI * cosNI) / (cosNI * cosNI)));
float G1o = 2 / (1 + safe_sqrtf(1 + alpha2 * (1 - cosNO * cosNO) / (cosNO * cosNO)));
float G1i = 2 / (1 + safe_sqrtf(1 + alpha2 * (1 - cosNI * cosNI) / (cosNI * cosNI)));
float G = G1o * G1i;
// eq. 20: (F*G*D)/(4*in*on)
float out = (G * D) * 0.25f / cosNO;
@ -234,8 +239,8 @@ __device int bsdf_microfacet_ggx_sample(const ShaderData *sd, const ShaderClosur
// eval BRDF*cosNI
float cosNI = dot(m_N, *omega_in);
// eq. 34: now calculate G1(i,m) and G1(o,m)
float G1o = 2 / (1 + sqrtf(1 + alpha2 * (1 - cosNO * cosNO) / (cosNO * cosNO)));
float G1i = 2 / (1 + sqrtf(1 + alpha2 * (1 - cosNI * cosNI) / (cosNI * cosNI)));
float G1o = 2 / (1 + safe_sqrtf(1 + alpha2 * (1 - cosNO * cosNO) / (cosNO * cosNO)));
float G1i = 2 / (1 + safe_sqrtf(1 + alpha2 * (1 - cosNI * cosNI) / (cosNI * cosNI)));
float G = G1o * G1i;
// eq. 21
float cosHI = dot(m, *omega_in);
@ -313,8 +318,8 @@ __device float3 bsdf_microfacet_beckmann_eval_reflect(const ShaderData *sd, cons
float cosThetaM4 = cosThetaM2 * cosThetaM2;
float D = expf(-tanThetaM2 / alpha2) / (M_PI_F * alpha2 * cosThetaM4);
// eq. 26, 27: now calculate G1(i,m) and G1(o,m)
float ao = 1 / (m_ab * sqrtf((1 - cosNO * cosNO) / (cosNO * cosNO)));
float ai = 1 / (m_ab * sqrtf((1 - cosNI * cosNI) / (cosNI * cosNI)));
float ao = 1 / (m_ab * safe_sqrtf((1 - cosNO * cosNO) / (cosNO * cosNO)));
float ai = 1 / (m_ab * safe_sqrtf((1 - cosNI * cosNI) / (cosNI * cosNI)));
float G1o = ao < 1.6f ? (3.535f * ao + 2.181f * ao * ao) / (1 + 2.276f * ao + 2.577f * ao * ao) : 1.0f;
float G1i = ai < 1.6f ? (3.535f * ai + 2.181f * ai * ai) / (1 + 2.276f * ai + 2.577f * ai * ai) : 1.0f;
float G = G1o * G1i;
@ -356,8 +361,8 @@ __device float3 bsdf_microfacet_beckmann_eval_transmit(const ShaderData *sd, con
float cosThetaM4 = cosThetaM2 * cosThetaM2;
float D = expf(-tanThetaM2 / alpha2) / (M_PI_F * alpha2 * cosThetaM4);
// eq. 26, 27: now calculate G1(i,m) and G1(o,m)
float ao = 1 / (m_ab * sqrtf((1 - cosNO * cosNO) / (cosNO * cosNO)));
float ai = 1 / (m_ab * sqrtf((1 - cosNI * cosNI) / (cosNI * cosNI)));
float ao = 1 / (m_ab * safe_sqrtf((1 - cosNO * cosNO) / (cosNO * cosNO)));
float ai = 1 / (m_ab * safe_sqrtf((1 - cosNI * cosNI) / (cosNI * cosNI)));
float G1o = ao < 1.6f ? (3.535f * ao + 2.181f * ao * ao) / (1 + 2.276f * ao + 2.577f * ao * ao) : 1.0f;
float G1i = ai < 1.6f ? (3.535f * ai + 2.181f * ai * ai) / (1 + 2.276f * ai + 2.577f * ai * ai) : 1.0f;
float G = G1o * G1i;
@ -389,8 +394,8 @@ __device int bsdf_microfacet_beckmann_sample(const ShaderData *sd, const ShaderC
// we take advantage of cos(atan(x)) == 1/sqrt(1+x^2)
//tttt and sin(atan(x)) == x/sqrt(1+x^2)
float alpha2 = m_ab * m_ab;
float tanThetaM = sqrtf(-alpha2 * logf(1 - randu));
float cosThetaM = 1 / sqrtf(1 + tanThetaM * tanThetaM);
float tanThetaM = safe_sqrtf(-alpha2 * logf(1 - randu));
float cosThetaM = 1 / safe_sqrtf(1 + tanThetaM * tanThetaM);
float sinThetaM = cosThetaM * tanThetaM;
float phiM = 2 * M_PI_F * randv;
float3 m = (cosf(phiM) * sinThetaM) * X +
@ -418,8 +423,8 @@ __device int bsdf_microfacet_beckmann_sample(const ShaderData *sd, const ShaderC
// Eval BRDF*cosNI
float cosNI = dot(m_N, *omega_in);
// eq. 26, 27: now calculate G1(i,m) and G1(o,m)
float ao = 1 / (m_ab * sqrtf((1 - cosNO * cosNO) / (cosNO * cosNO)));
float ai = 1 / (m_ab * sqrtf((1 - cosNI * cosNI) / (cosNI * cosNI)));
float ao = 1 / (m_ab * safe_sqrtf((1 - cosNO * cosNO) / (cosNO * cosNO)));
float ai = 1 / (m_ab * safe_sqrtf((1 - cosNI * cosNI) / (cosNI * cosNI)));
float G1o = ao < 1.6f ? (3.535f * ao + 2.181f * ao * ao) / (1 + 2.276f * ao + 2.577f * ao * ao) : 1.0f;
float G1i = ai < 1.6f ? (3.535f * ai + 2.181f * ai * ai) / (1 + 2.276f * ai + 2.577f * ai * ai) : 1.0f;
float G = G1o * G1i;
@ -469,8 +474,8 @@ __device int bsdf_microfacet_beckmann_sample(const ShaderData *sd, const ShaderC
// eval BRDF*cosNI
float cosNI = dot(m_N, *omega_in);
// eq. 26, 27: now calculate G1(i,m) and G1(o,m)
float ao = 1 / (m_ab * sqrtf((1 - cosNO * cosNO) / (cosNO * cosNO)));
float ai = 1 / (m_ab * sqrtf((1 - cosNI * cosNI) / (cosNI * cosNI)));
float ao = 1 / (m_ab * safe_sqrtf((1 - cosNO * cosNO) / (cosNO * cosNO)));
float ai = 1 / (m_ab * safe_sqrtf((1 - cosNI * cosNI) / (cosNI * cosNI)));
float G1o = ao < 1.6f ? (3.535f * ao + 2.181f * ao * ao) / (1 + 2.276f * ao + 2.577f * ao * ao) : 1.0f;
float G1i = ai < 1.6f ? (3.535f * ai + 2.181f * ai * ai) / (1 + 2.276f * ai + 2.577f * ai * ai) : 1.0f;
float G = G1o * G1i;