Commit: 6f820664c436601917c34de75e0b3c757c460e5e
Author: Thomas Dinges
Date: Tue Feb 17 18:39:03 2015 +0100
Branches: master
https://developer.blender.org/rB6f820664c436601917c34de75e0b3c757c460e5e
Cleanup: Deduplicate area light sampling code.
===================================================================
M intern/cycles/kernel/kernel_light.h
===================================================================
diff --git a/intern/cycles/kernel/kernel_light.h
b/intern/cycles/kernel/kernel_light.h
index 41920e4..acad798 100644
--- a/intern/cycles/kernel/kernel_light.h
+++ b/intern/cycles/kernel/kernel_light.h
@@ -178,7 +178,7 @@ ccl_device float3 area_light_sample(float3 P,
float3 light_p,
float3 axisu, float3 axisv,
float randu, float randv,
- float *pdf)
+ float *pdf, bool return_coords)
{
/* In our name system we're using P for the center,
* which is o in the paper.
@@ -198,13 +198,10 @@ ccl_device float3 area_light_sample(float3 P,
z *= -1.0f;
z0 *= -1.0f;
}
- float z0sq = z0 * z0;
float x0 = dot(dir, x);
float y0 = dot(dir, y);
float x1 = x0 + axisu_len;
float y1 = y0 + axisv_len;
- float y0sq = y0 * y0;
- float y1sq = y1 * y1;
/* Create vectors to four vertices. */
float3 v00 = make_float3(x0, y0, z0);
float3 v01 = make_float3(x0, y1, z0);
@@ -227,83 +224,35 @@ ccl_device float3 area_light_sample(float3 P,
float k = M_2PI_F - g2 - g3;
/* Compute solid angle from internal angles. */
float S = g0 + g1 - k;
-
- /* Compute cu. */
- float au = randu * S + k;
- float fu = (cosf(au) * b0 - b1) / sinf(au);
- float cu = 1.0f / sqrtf(fu * fu + b0sq) * (fu > 0.0f ? 1.0f : -1.0f);
- cu = clamp(cu, -1.0f, 1.0f);
- /* Compute xu. */
- float xu = -(cu * z0) / sqrtf(1.0f - cu * cu);
- xu = clamp(xu, x0, x1);
- /* Compute yv. */
- float d = sqrtf(xu * xu + z0sq);
- float h0 = y0 / sqrtf(d * d + y0sq);
- float h1 = y1 / sqrtf(d * d + y1sq);
- float hv = h0 + randv * (h1 - h0), hv2 = hv * hv;
- float yv = (hv2 < 1.0f - 1e-6f) ? (hv * d) / sqrtf(1.0f - hv2) : y1;
-
if(S != 0.0f)
*pdf = 1.0f / S;
else
*pdf = 0.0f;
- /* Transform (xu, yv, z0) to world coords. */
- return P + xu * x + yv * y + z0 * z;
-}
-
-/* TODO(sergey): This is actually a duplicated code from above, but how to
avoid
- * this without having some nasty function with loads of parameters?
- */
-ccl_device float area_light_pdf(float3 P,
- float3 light_p,
- float3 axisu, float3 axisv)
-{
- /* In our name system we're using P for the center,
- * which is o in the paper.
- */
-
- float3 corner = light_p - axisu * 0.5f - axisv * 0.5f;
- float axisu_len, axisv_len;
- /* Compute local reference system R. */
- float3 x = normalize_len(axisu, &axisu_len);
- float3 y = normalize_len(axisv, &axisv_len);
- float3 z = cross(x, y);
- /* Compute rectangle coords in local reference system. */
- float3 dir = corner - P;
- float z0 = dot(dir, z);
- /* Flip 'z' to make it point against Q. */
- if(z0 > 0.0f) {
- z *= -1.0f;
- z0 *= -1.0f;
+ if(return_coords) {
+ /* Compute cu. */
+ float au = randu * S + k;
+ float fu = (cosf(au) * b0 - b1) / sinf(au);
+ float cu = 1.0f / sqrtf(fu * fu + b0sq) * (fu > 0.0f ? 1.0f :
-1.0f);
+ cu = clamp(cu, -1.0f, 1.0f);
+ /* Compute xu. */
+ float xu = -(cu * z0) / sqrtf(1.0f - cu * cu);
+ xu = clamp(xu, x0, x1);
+ /* Compute yv. */
+ float z0sq = z0 * z0;
+ float y0sq = y0 * y0;
+ float y1sq = y1 * y1;
+ float d = sqrtf(xu * xu + z0sq);
+ float h0 = y0 / sqrtf(d * d + y0sq);
+ float h1 = y1 / sqrtf(d * d + y1sq);
+ float hv = h0 + randv * (h1 - h0), hv2 = hv * hv;
+ float yv = (hv2 < 1.0f - 1e-6f) ? (hv * d) / sqrtf(1.0f - hv2)
: y1;
+
+ /* Transform (xu, yv, z0) to world coords. */
+ return P + xu * x + yv * y + z0 * z;
}
- float x0 = dot(dir, x);
- float y0 = dot(dir, y);
- float x1 = x0 + axisu_len;
- float y1 = y0 + axisv_len;
- /* Create vectors to four vertices. */
- float3 v00 = make_float3(x0, y0, z0);
- float3 v01 = make_float3(x0, y1, z0);
- float3 v10 = make_float3(x1, y0, z0);
- float3 v11 = make_float3(x1, y1, z0);
- /* Compute normals to edges. */
- float3 n0 = normalize(cross(v00, v10));
- float3 n1 = normalize(cross(v10, v11));
- float3 n2 = normalize(cross(v11, v01));
- float3 n3 = normalize(cross(v01, v00));
- /* Compute internal angles (gamma_i). */
- float g0 = safe_acosf(-dot(n0, n1));
- float g1 = safe_acosf(-dot(n1, n2));
- float g2 = safe_acosf(-dot(n2, n3));
- float g3 = safe_acosf(-dot(n3, n0));
- /* Compute predefined constants. */
- float k = M_2PI_F - g2 - g3;
- /* Compute solid angle from internal angles. */
- float S = g0 + g1 - k;
- if(S != 0.0f)
- return 1.0f / S;
else
- return 0.0f;
+ return make_float3(0.0f, 0.0f, 0.0f);
}
ccl_device float spot_light_attenuation(float4 data1, float4 data2,
LightSample *ls)
@@ -421,7 +370,7 @@ ccl_device void lamp_light_sample(KernelGlobals *kg, int
lamp,
ls->P = area_light_sample(P, ls->P,
axisu, axisv,
randu, randv,
- &ls->pdf);
+ &ls->pdf, true);
ls->Ng = D;
ls->D = normalize_len(ls->P - P, &ls->t);
@@ -553,7 +502,7 @@ ccl_device bool lamp_light_eval(KernelGlobals *kg, int
lamp, float3 P, float3 D,
ls->D = D;
ls->Ng = Ng;
- ls->pdf = area_light_pdf(P, ls->P, axisu, axisv);
+ area_light_sample(P, ls->P, axisu, axisv, 0, 0, &ls->pdf,
false);
ls->eval_fac = 0.25f*invarea;
}
else
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