1 files changed, 32 insertions, 1 deletions
diff --git a/source/blender/render/intern/source/shadeoutput.c b/source/blender/render/intern/source/shadeoutput.c
index 3d6462e09a0..8dea0930b9e 100644
--- a/source/blender/render/intern/source/shadeoutput.c
+++ b/source/blender/render/intern/source/shadeoutput.c
@@ -2141,9 +2141,19 @@ const float (*RE_object_instance_get_matrix(struct ObjectInstanceRen *obi, int m
 	return NULL;
 }
 
+float RE_object_instance_get_object_pass_index(struct ObjectInstanceRen *obi)
+{
+	return obi->ob->index;
+}
+
+float RE_object_instance_get_random_id(struct ObjectInstanceRen *obi)
+{
+	return obi->random_id;
+}
+
 const float (*RE_render_current_get_matrix(int matrix_id))[4]
 {
-	switch(matrix_id) {
+	switch (matrix_id) {
 		case RE_VIEW_MATRIX:
 			return (const float(*)[4])R.viewmat;
 		case RE_VIEWINV_MATRIX:
@@ -2151,3 +2161,24 @@ const float (*RE_render_current_get_matrix(int matrix_id))[4]
 	}
 	return NULL;
 }
+
+float RE_fresnel_dielectric(float incoming[3], float normal[3], float eta)
+{
+	/* compute fresnel reflectance without explicitly computing
+	 * the refracted direction */
+	float c = fabs(dot_v3v3(incoming, normal));
+	float g = eta * eta - 1.0 + c * c;
+	float result;
+
+	if (g > 0.0) {
+		g = sqrtf(g);
+		float A = (g - c) / (g + c);
+		float B = (c * (g + c) - 1.0) / (c * (g - c) + 1.0);
+		result = 0.5 * A * A * (1.0 + B * B);
+	}
+	else {
+		result = 1.0;  /* TIR (no refracted component) */
+	}
+
+	return result;
+}