0025201: Visualization - Implementing soft shadows and ambient occlusion in OCCT ray-tracing core

src/Graphic3d/Graphic3d_BSDF.cxx

@@ -0,0 +1,159 @@
+// Created on: 2015-01-19
+// Created by: Denis BOGOLEPOV
+// Copyright (c) 2014 OPEN CASCADE SAS
+//
+// This file is part of Open CASCADE Technology software library.
+//
+// This library is free software; you can redistribute it and/or modify it under
+// the terms of the GNU Lesser General Public License version 2.1 as published
+// by the Free Software Foundation, with special exception defined in the file
+// OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
+// distribution for complete text of the license and disclaimer of any warranty.
+//
+// Alternatively, this file may be used under the terms of Open CASCADE
+// commercial license or contractual agreement.
+
+#include <Graphic3d_BSDF.hxx>
+
+#include <algorithm>
+
+// =======================================================================
+// function : Serialize
+// purpose  :
+// =======================================================================
+Graphic3d_Vec4 Graphic3d_Fresnel::Serialize() const
+{
+  Graphic3d_Vec4 aData = Graphic3d_Vec4 (myFresnelData, 0.f);
+
+  if (myFresnelType != Graphic3d_FM_SCHLICK)
+  {
+    aData.x() = -static_cast<Standard_ShortReal> (myFresnelType);
+  }
+
+  return aData;
+}
+
+// =======================================================================
+// function : fresnelNormal
+// purpose  :
+// =======================================================================
+inline Standard_ShortReal fresnelNormal (Standard_ShortReal theN,
+                                         Standard_ShortReal theK)
+{
+  return ((theN - 1.f) * (theN - 1.f) + theK * theK) /
+         ((theN + 1.f) * (theN + 1.f) + theK * theK);
+}
+
+// =======================================================================
+// function : CreateConductor
+// purpose  :
+// =======================================================================
+Graphic3d_Fresnel Graphic3d_Fresnel::CreateConductor (const Graphic3d_Vec3& theRefractionIndex,
+                                                      const Graphic3d_Vec3& theAbsorptionIndex)
+{
+  return Graphic3d_Fresnel (Graphic3d_FM_SCHLICK,
+    Graphic3d_Vec3 (fresnelNormal (theRefractionIndex.x(), theAbsorptionIndex.x()),
+                    fresnelNormal (theRefractionIndex.y(), theAbsorptionIndex.y()),
+                    fresnelNormal (theRefractionIndex.z(), theAbsorptionIndex.z())));
+}
+
+// =======================================================================
+// function : Normalize
+// purpose  :
+// =======================================================================
+void Graphic3d_BSDF::Normalize()
+{
+  Standard_ShortReal aMax = std::max (Kd.x() + Ks.x() + Kr.x() + Kt.x(),
+                            std::max (Kd.y() + Ks.y() + Kr.y() + Kt.y(),
+                                      Kd.z() + Ks.z() + Kr.z() + Kt.z()));
+
+  if (aMax > 1.f)
+  {
+    Kd /= aMax;
+    Ks /= aMax;
+    Kr /= aMax;
+    Ks /= aMax;
+  }
+}
+
+// =======================================================================
+// function : CreateDiffuse
+// purpose  :
+// =======================================================================
+Graphic3d_BSDF Graphic3d_BSDF::CreateDiffuse (const Graphic3d_Vec3& theWeight)
+{
+  Graphic3d_BSDF aBSDF;
+
+  aBSDF.Kd = theWeight;
+
+  return aBSDF;
+}
+
+// =======================================================================
+// function : CreateMetallic
+// purpose  :
+// =======================================================================
+Graphic3d_BSDF Graphic3d_BSDF::CreateMetallic (const Graphic3d_Vec3&    theWeight,
+                                               const Graphic3d_Fresnel& theFresnel,
+                                               const Standard_ShortReal theRoughness)
+{
+  Graphic3d_BSDF aBSDF;
+
+  aBSDF.Roughness = theRoughness;
+
+  // Selecting between specular and glossy
+  // BRDF depending on the given roughness
+  if (aBSDF.Roughness > 0.f)
+  {
+    aBSDF.Ks = theWeight;
+  }
+  else
+  {
+    aBSDF.Kr = theWeight;
+  }
+
+  aBSDF.Fresnel = theFresnel;
+
+  return aBSDF;
+}
+
+// =======================================================================
+// function : CreateTransparent
+// purpose  :
+// =======================================================================
+Graphic3d_BSDF Graphic3d_BSDF::CreateTransparent (const Graphic3d_Vec3&    theWeight,
+                                                  const Graphic3d_Vec3&    theAbsorptionColor,
+                                                  const Standard_ShortReal theAbsorptionCoeff)
+{
+  Graphic3d_BSDF aBSDF;
+
+  aBSDF.Kt = theWeight;
+
+  aBSDF.AbsorptionColor = theAbsorptionColor;
+  aBSDF.AbsorptionCoeff = theAbsorptionCoeff;
+
+  aBSDF.Fresnel = Graphic3d_Fresnel::CreateConstant (0.f);
+
+  return aBSDF;
+}
+
+// =======================================================================
+// function : CreateGlass
+// purpose  :
+// =======================================================================
+Graphic3d_BSDF Graphic3d_BSDF::CreateGlass (const Graphic3d_Vec3&    theWeight,
+                                            const Graphic3d_Vec3&    theAbsorptionColor,
+                                            const Standard_ShortReal theAbsorptionCoeff,
+                                            const Standard_ShortReal theRefractionIndex)
+{
+  Graphic3d_BSDF aBSDF;
+
+  aBSDF.Kt = theWeight;
+
+  aBSDF.AbsorptionColor = theAbsorptionColor;
+  aBSDF.AbsorptionCoeff = theAbsorptionCoeff;
+
+  aBSDF.Fresnel = Graphic3d_Fresnel::CreateDielectric (theRefractionIndex);
+
+  return aBSDF;
+}