Changeset 2944 for GTP/trunk/App/Demos/Vis/FriendlyCulling/src/ShadowMapping.cpp

Timestamp:

09/15/08 00:07:01 (16 years ago)

Author:

mattausch

Message:

nopt not working yet

File:

• GTP/trunk/App/Demos/Vis/FriendlyCulling/src/ShadowMapping.cpp (modified) (8 diffs)

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

@@ -187 +187 @@
 
 
+// z0 is the point that lies on the parallel plane to the near plane through e (A)
+//and on the near plane of the C frustum (the plane z = bZmax) and on the line x = e.x
+Vector3 ShadowMap::GetLightSpaceZ0(const Matrix4x4 &lightSpace, 
+                                                                   const Vector3 &e, 
+                                                                   const float maxZ, 
+                                                                   const Vector3 &eyeDir) const 
+{
+        // to calculate the parallel plane to the near plane through e we 
+        // calculate the plane A with the three points
+        Plane3 planeA(e, eyeDir);
+
+        planeA.Transform(lightSpace);
+        
+        // get the parameters of A from the plane equation n dot d = 0
+        const float d = planeA.mD;
+        const Vector3 n = planeA.mNormal;
+        
+        // transform to light space
+        const Vector3 e_ls = lightSpace * e;
+
+        Vector3 z0;
+
+        z0.x = e_ls.x;
+        z0.y = (d - n.z * maxZ - n.x * e_ls.x) / n.y;
+        z0.z = maxZ;
+
+        return z0;
+        //return V3(e_ls.x(),(d-n.z()*b_lsZmax-n.x()*e_ls.x())/n.y(),b_lsZmax);
+}
+
+
+float ShadowMap::ComputeNOpt(const Matrix4x4 &lightSpace, 
+                                                         const AxisAlignedBox3 &extremalPoints,
+                                                         const VertexArray &body) const
+{
+        const Vector3 nearPt = GetNearCameraPointE(body);
+        const Vector3 eyeDir = mCamera->GetDirection();
+
+        Matrix4x4 eyeView;
+        mCamera->GetModelViewMatrix(eyeView);
+
+        const Matrix4x4 invLightSpace = Invert(lightSpace);
+
+        const Vector3 z0_ls = GetLightSpaceZ0(lightSpace, nearPt, extremalPoints.Max().z, eyeDir);
+        const Vector3 z1_ls = Vector3(z0_ls.x, z0_ls.y, extremalPoints.Min().z);
+        
+        // transform back to world space
+        const Vector3 z0_ws = invLightSpace * z0_ls;
+        const Vector3 z1_ws = invLightSpace * z1_ls;
+
+        // transform to eye space
+        const Vector3 z0_es = eyeView * z0_ws;
+        const Vector3 z1_es = eyeView * z1_ws;
+
+        const float z0 = z0_es.z;
+        const float z1 = z1_es.z;
+
+        cout << "z0 ls: " << z0_ls << " z1 ls: " << z1_ls << endl;
+        cout << "z0: " << z0_es << " z1: " << z1_es << endl;
+
+        const float d = fabs(extremalPoints.Max()[2] - extremalPoints.Min()[2]); 
+
+        const float n = d / (sqrt(z1 / z0) - 1.0f);
+
+        return n;
+}
+
+
 float ShadowMap::ComputeN(const AxisAlignedBox3 &extremalPoints) const 
 {
-        const float n = mCamera->GetNear();
+        const float nearPlane = mCamera->GetNear();
         
         const float d = fabs(extremalPoints.Max()[2] - extremalPoints.Min()[2]); 
@@ -196 +264 @@
         const float sinGamma = sin(fabs(acos(dotProd)));
 
-        return (n + sqrt(n * (n + d * sinGamma))) /  sinGamma;
+        // test for values close to zero
+        if (sinGamma < 1e-6f) return 1e6f;
+        
+        return (nearPlane + sqrt(nearPlane * (nearPlane + d * sinGamma))) /  sinGamma;
 }
 
@@ -205 +276 @@
                                                                                  )
 {
-        //return IdentityMatrix();
-
         AxisAlignedBox3 bounds_ls = GetExtremalPoints(lightSpace, body);
 
@@ -213 +282 @@
         //-- first find the free parameter values n, and P (the projection center), and the projection depth
 
-        const float n = ComputeN(bounds_ls);
-
-        //cout << "n: " << n << endl;
+        //const float n = ComputeN(bounds_ls);
+        const float n = ComputeNOpt(lightSpace, extremalPoints, body);
+
+        cout << "n: " << n << endl;
+
+        if (n >= 1e6f) // light direction nearly parallel to view => switch to uniform
+                return IdentityMatrix();
 
         const Vector3 nearPt = GetNearCameraPointE(body);
@@ -358 +431 @@
 
         VertexArray frustumPoints;
-        //Vector3 lightDir = Vector3(0, 0, -1);
         IncludeLightVolume(*polyhedron, frustumPoints, mLight->GetDirection(), mSceneBox);
 
@@ -392 +464 @@
         //look(from position, into the direction of the projected direction, with unchanged up-vector)
         //const Matrix4x4 frame = MyLookAt2(Vector3::ZERO(), projViewDir, Vector3::UNIT_Y());
-        const Matrix4x4 frame = MyLookAt(Vector3::ZERO(), projViewDir, Vector3::UNIT_Y());
+        const Matrix4x4 frame = LookAt(Vector3::ZERO(), projViewDir, Vector3::UNIT_Y());
 
         lightProj *= frame;
@@ -600 +672 @@
 
         Vector3 upVec = CalcUpVec(mCamera->GetDirection(), dir);
-        Matrix4x4 lightView = MyLookAt(mShadowCam->GetPosition(), dir, upVec);
+        Matrix4x4 lightView = LookAt(mShadowCam->GetPosition(), dir, upVec);
 
         mShadowCam->mViewOrientation = lightView;
@@ -606 +678 @@
         glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
-        glPolygonOffset(1.0f, 2000.0f);
+        glPolygonOffset(5.0f, 100.0f);
         glEnable(GL_POLYGON_OFFSET_FILL);