Changeset 2915

Timestamp:

09/08/08 10:14:49 (16 years ago)

Author:

mattausch

Message:

 

Location:

GTP/trunk/App/Demos/Vis/FriendlyCulling/src

Files:

• Matrix4x4.cpp (modified) (1 diff)
• Matrix4x4.h (modified) (1 diff)
• ShadowMapping.cpp (modified) (10 diffs)
• ShadowMapping.h (modified) (1 diff)

GTP/trunk/App/Demos/Vis/FriendlyCulling/src/Matrix4x4.cpp

@@ -676 +676 @@
 
         m.x[0][0] = -2.0f / (box.Max()[0] - box.Min()[0]);
+        m.x[0][1] = .0f;
+        m.x[0][2] = .0f;
+        m.x[0][3] = .0f;
+
         m.x[1][0] = .0f;
+        m.x[1][1] = -2.0f / (box.Max()[1] - box.Min()[1]);
+        m.x[1][2] = .0f;
+        m.x[1][3] = .0f;
+
         m.x[2][0] = .0f;
+        m.x[2][1] = .0f;
+        m.x[2][2] = -2.0f / (box.Max()[2] - box.Min()[2]);
+        m.x[2][3] = .0f;
+
         m.x[3][0] = (box.Max()[0] + box.Min()[0]) / (box.Max()[0] - box.Min()[0]);
-
+        m.x[3][1] = (box.Max()[1] + box.Min()[1]) / (box.Max()[1] - box.Min()[1]);
+        m.x[3][2] = (box.Max()[2] + box.Min()[2]) / (box.Max()[2] - box.Min()[2]);
+        m.x[3][3] = 1.0f;
+
+        return m;
+}
+
+
+//output is initialized with the same result as glFrustum
+Matrix4x4 GetFrustum(float left, float right, float bottom, float top, float near, float far)
+{
+        Matrix4x4 m;
+
+        const float xDif = 1.0f / (right - left);
+        const float yDif = 1.0f / (top - bottom);
+        const float zDif = 1.0f / (near - far);
+
+        m.x[0][0] = 2.0f * near * xDif;
         m.x[0][1] = .0f;
-        m.x[1][1] = -2.0f / (box.Max()[1] - box.Min()[1]);
-        m.x[2][1] = .0f;
-        m.x[3][1] = (box.Max()[1] + box.Min()[1]) / (box.Max()[1] - box.Min()[1]);
-
         m.x[0][2] = .0f;
+        m.x[0][3] = .0f;
+
+        m.x[1][0] = .0f;
+        m.x[1][1] = 2.0f * near * yDif;
         m.x[1][2] = .0f;
-        m.x[2][2] = -2.0f / (box.Max()[2] - box.Min()[2]);
-        m.x[3][2] = (box.Max()[2] + box.Min()[2]) / (box.Max()[2] - box.Min()[2]);
-
-        m.x[0][3] = .0f;
         m.x[1][3] = .0f;
-        m.x[2][3] = .0f;
-        m.x[3][3] = 1.0f;
-
-        return m;
-}
-
-
-}
+
+        m.x[2][0] = (right + left) * xDif;
+        m.x[2][1] = (top + bottom)* yDif;
+        m.x[2][2] = (far + near) * zDif;
+        m.x[2][3] = -1.0f;
+
+        m.x[3][0] = .0f;
+        m.x[3][1] = .0f;
+        m.x[3][2] = 2.0f * near * far * zDif;
+        m.x[3][3] = .0f;
+}
+
+
+
+}

GTP/trunk/App/Demos/Vis/FriendlyCulling/src/Matrix4x4.h

@@ -111 +111 @@
         friend Matrix4x4 GetFittingProjectionMatrix(const AxisAlignedBox3 &box);
 
+        //output is initialized with the same result as glFrustum
+        friend Matrix4x4 GetFrustum(float left, float right, float bottom, float top, float near, float far);
+
         // Overloaded output operator.
         friend std::ostream& operator<< (std::ostream &s, const Matrix4x4 &M);

GTP/trunk/App/Demos/Vis/FriendlyCulling/src/ShadowMapping.cpp

@@ -144 +144 @@
         VertexArray::const_iterator it, it_end = vertices.end();
 
-        //cout << "=================" << endl;
-
         for (it = vertices.begin(); it != it_end; ++ it)
         {
@@ -155 +153 @@
                 v -= Magnitude(mSceneBox.Diagonal()) * lightDir;
 
-                //cout << "pt: " << v << endl;
                 SimpleRay ray(v, lightDir);
 
@@ -163 +160 @@
                 {
                         Vector3 newpt = ray.Extrap(tNear);
-                        Vector3 newpt2 = ray.Extrap(tFar);
-
-                        frustumPoints.push_back(newpt);
-
-                        //if (newpt.z < 220) cout << "ipt: " << newpt << " " << *it << endl;
+                        frustumPoints.push_back(newpt);                 
                 }
         }
@@ -173 +166 @@
 
 
-bool ShadowMap::CalcLightProjection(Matrix4x4 &lightProj)
-{
-        DEL_PTR(polyhedron);
+bool ShadowMap::CalcLightProjectionLispSM(Matrix4x4 &lightProj)
+{
+        Matrix4x4 lispMtx = IdentityMatrix();
+
+        const float dotProd = DotProd(mCamera->GetDirection(), mShadowCam->GetDirection());
+        const float sinGamma = sqrt(1.0f - dotProd * dotProd);
 
 
@@ -181 +177 @@
         //-- First step: calc frustum clipped by scene box
 
+        DEL_PTR(polyhedron);
         polyhedron = CalcClippedFrustum(mSceneBox);
 
@@ -200 +197 @@
         Matrix4x4 lightView;
         mShadowCam->GetModelViewMatrix(lightView);
-
-        //Matrix4x4 inverseCamView;
-        //mCamera->GetModelViewMatrix(inverseCamView);
-        //Invert(inverseCamView);
-
-        //Matrix4x4 m = inverseCamView * lightView;
 
         VertexArray::const_iterator it, it_end = frustumPoints.end();
@@ -212 +203 @@
         {
                 Vector3 pt = *it;
-
-                //pt = inverseCamView * pt;
                 pt = lightView * pt;
-                //v = m * v;
 
                 extremalPoints.Include(pt);
-                //cout << "pt: " << pt << endl;
+        }
+
+
+        ///////////////
+        //-- We apply the lispsm algorithm in order to calculate an optimal light projection matrix
+
+        // use lispsm formulas
+        const float fac = 1.0f / sinGamma;
+        
+        const float z_n = fac * mCamera->GetNear();
+
+        // light space y size
+        const float d = fabs(extremalPoints.Max()[1] - extremalPoints.Min()[1]); 
+
+        const float z_f = z_n + d * sinGamma;
+
+        // this is the famous n parameter
+        const float n = (z_n + sqrt(z_f * z_n)) /sinGamma;
+        const float f = n + d;
+
+        const Vector3 nearPt = mShadowCam->GetNear() * mShadowCam->GetDirection() + mShadowCam->GetPosition();
+
+        //get the coordinates of the near camera point in light space
+        const Vector3 lsNear = lightView * nearPt;
+
+        //c start has the x and y coordinate of e, the z coord of B.min()
+        const Vector3 startPt = Vector3(lsNear.x, lsNear.y, extremalPoints.Max().z);
+
+        // the new projection center
+        Vector3 projCenter = startPt - Vector3(0, 0, 1) * n;
+
+        //construct a translation that moves to the projection center
+        const Matrix4x4 projectionCenter = TranslationMatrix(-projCenter);
+
+        lightProj = IdentityMatrix();
+
+        //one possibility for a simple perspective transformation matrix
+        //with the two parameters n(near) and f(far) in y direction
+        
+        // a = (f+n)/(f-n); b = -2*f*n/(f-n);
+        // [ 1 0 0 0]
+        // [ 0 a 0 b]
+        // [ 0 0 1 0]
+        // [ 0 1 0 0]
+
+        lightProj.x[1][1] = (f + n) / (f - n);           
+        lightProj.x[1][3] = 1.0f;
+
+        lightProj.x[3][1] = -2.0f * f * n / (f - n);            
+        lightProj.x[3][3] = 0.0f;                               
+
+        cout << "here4\n" << lightProj << endl;
+
+        // transform into OpenGL right handed system
+        Matrix4x4 scale = ScaleMatrix(1.0f, 1.0f, -1.0f);
+
+        lightProj = projectionCenter * scale * lightProj;
+
+        Vector3 pmax = extremalPoints.Max();
+        Vector3 pmin = extremalPoints.Min();
+
+        cout << "min: " << lightProj * pmin << endl;
+        cout << "max: " << lightProj * pmax << endl;
+        
+
+        return true;
+}
+
+
+bool ShadowMap::CalcLightProjection(Matrix4x4 &lightProj)
+{
+        DEL_PTR(polyhedron);
+
+
+        ///////////////////
+        //-- First step: calc frustum clipped by scene box
+
+        polyhedron = CalcClippedFrustum(mSceneBox);
+
+        if (!polyhedron) return false; // something is wrong
+
+        // include the part of the light volume that "sees" the frustum
+        // we only require frustum vertices
+
+        VertexArray frustumPoints;
+        IncludeLightVolume(*polyhedron, frustumPoints, mShadowCam->GetDirection(), mSceneBox);
+
+
+        ///////////////
+        //-- transform points from world view to light view and calculate extremal points
+
+        AxisAlignedBox3 extremalPoints;
+        extremalPoints.Initialize();
+
+        Matrix4x4 lightView;
+        mShadowCam->GetModelViewMatrix(lightView);
+
+        VertexArray::const_iterator it, it_end = frustumPoints.end();
+                
+        for (it = frustumPoints.begin(); it != it_end; ++ it)
+        {
+                Vector3 pt = *it;
+                pt = lightView * pt;
+
+                extremalPoints.Include(pt);
         }
 
         // focus projection matrix on the extremal points
         lightProj = GetFittingProjectionMatrix(extremalPoints);
-
-        /*Vector3 pmax = extremalPoints.Max();
-        Vector3 pmin = extremalPoints.Min();
-
-        cout << "min: " << lightProj * pmin << endl;
-        cout << "max: " << lightProj * pmax << endl;
-        
-        for (it = frustumPoints.begin(); it != it_end; ++ it)
-        {
-                Vector3 pt = *it;
-                
-                pt = lightView * pt;
-                pt = lightProj * pt;
-
-                cout << "pt: " << pt << endl;
-        }*/
 
         return true;
@@ -283 +359 @@
 
         Polyhedron *p = new Polyhedron(polygons);
-        //return p;
-        
         Polyhedron *clippedPolyhedron = box.CalcIntersection(*p);
         
@@ -348 +422 @@
         mShadowCam->GetModelViewMatrix(lightView);
 
-        CalcLightProjection(lightProj);
+        //CalcLightProjection(lightProj);
+        CalcLightProjectionLispSM(lightProj);
 
         glMatrixMode(GL_PROJECTION);
@@ -354 +429 @@
         glLoadMatrixf((float *)lightProj.x);
 
-        //cout << "new:\n" << lightProj << endl;
+        cout << "new:\n" << lightProj << endl;
 
         glMatrixMode(GL_MODELVIEW);

GTP/trunk/App/Demos/Vis/FriendlyCulling/src/ShadowMapping.h

@@ -63 +63 @@
         */
         Polyhedron *CalcClippedFrustum(const AxisAlignedBox3 &box) const;
-
-
+        
+        bool CalcLightProjectionLispSM(Matrix4x4 &lightProj);
         bool CalcLightProjection(Matrix4x4 &lightProj);