C# ShadingState.addSample方法代码示例

 public void getSamples(ShadingState state)
 {
     Vector3 d = Point3.sub(lightPoint, state.getPoint(), new Vector3());
     if (Vector3.dot(d, state.getNormal()) > 0 && Vector3.dot(d, state.getGeoNormal()) > 0)
     {
         LightSample dest = new LightSample();
         // prepare shadow ray
         dest.setShadowRay(new Ray(state.getPoint(), lightPoint));
         float scale = 1.0f / (float)(4 * Math.PI * lightPoint.distanceToSquared(state.getPoint()));
         dest.setRadiance(power, power);
         dest.getDiffuseRadiance().mul(scale);
         dest.getSpecularRadiance().mul(scale);
         dest.traceShadow(state);
         state.addSample(dest);
     }
 }

 public void getSamples(ShadingState state)
 {
     if (storedPhotons == 0)
         return;
     NearestPhotons np = new NearestPhotons(state.getPoint(), gatherNum, gatherRadius * gatherRadius);
     locatePhotons(np);
     if (np.found < 8)
         return;
     Point3 ppos = new Point3();
     Vector3 pdir = new Vector3();
     Vector3 pvec = new Vector3();
     float invArea = 1.0f / ((float)Math.PI * np.dist2[0]);
     float maxNDist = np.dist2[0] * 0.05f;
     float f2r2 = 1.0f / (filterValue * filterValue * np.dist2[0]);
     float fInv = 1.0f / (1.0f - 2.0f / (3.0f * filterValue));
     for (int i = 1; i <= np.found; i++)
     {
         Photon phot = np.index[i];
         Vector3.decode(phot.dir, pdir);
         float cos = -Vector3.dot(pdir, state.getNormal());
         if (cos > 0.001)
         {
             ppos.set(phot.x, phot.y, phot.z);
             Point3.sub(ppos, state.getPoint(), pvec);
             float pcos = Vector3.dot(pvec, state.getNormal());
             if ((pcos < maxNDist) && (pcos > -maxNDist))
             {
                 LightSample sample = new LightSample();
                 sample.setShadowRay(new Ray(state.getPoint(), pdir.negate()));
                 sample.setRadiance(new Color().setRGBE(np.index[i].power).mul(invArea / cos), Color.BLACK);
                 sample.getDiffuseRadiance().mul((1.0f - (float)Math.Sqrt(np.dist2[i] * f2r2)) * fInv);
                 state.addSample(sample);
             }
         }
     }
 }

        public void getSamples(ShadingState state)
        {
            if (samples == null)
            {
                int n = state.getDiffuseDepth() > 0 ? 1 : numSamples;
                for (int i = 0; i < n; i++)
                {
                    // random offset on unit square, we use the infinite version of
                    // getRandom because the light sampling is adaptive
                    double randX = state.getRandom(i, 0, n);
                    double randY = state.getRandom(i, 1, n);
                    int x = 0;
                    while (randX >= colHistogram[x] && x < colHistogram.Length - 1)
                        x++;
                    float[] rowHistogram = imageHistogram[x];
                    int y = 0;
                    while (randY >= rowHistogram[y] && y < rowHistogram.Length - 1)
                        y++;
                    // sample from (x, y)
                    float u = (float)((x == 0) ? (randX / colHistogram[0]) : ((randX - colHistogram[x - 1]) / (colHistogram[x] - colHistogram[x - 1])));
                    float v = (float)((y == 0) ? (randY / rowHistogram[0]) : ((randY - rowHistogram[y - 1]) / (rowHistogram[y] - rowHistogram[y - 1])));

                    float px = ((x == 0) ? colHistogram[0] : (colHistogram[x] - colHistogram[x - 1]));
                    float py = ((y == 0) ? rowHistogram[0] : (rowHistogram[y] - rowHistogram[y - 1]));

                    float su = (x + u) / colHistogram.Length;
                    float sv = (y + v) / rowHistogram.Length;
                    float invP = (float)Math.Sin(sv * Math.PI) * jacobian / (n * px * py);
                    Vector3 dir = getDirection(su, sv);
                    basis.transform(dir);
                    if (Vector3.dot(dir, state.getGeoNormal()) > 0)
                    {
                        LightSample dest = new LightSample();
                        dest.setShadowRay(new Ray(state.getPoint(), dir));
                        dest.getShadowRay().setMax(float.MaxValue);
                        Color radiance = texture.getPixel(su, sv);
                        dest.setRadiance(radiance, radiance);
                        dest.getDiffuseRadiance().mul(invP);
                        dest.getSpecularRadiance().mul(invP);
                        dest.traceShadow(state);
                        state.addSample(dest);
                    }
                }
            }
            else
            {
                for (int i = 0; i < numSamples; i++)
                {
                    if (Vector3.dot(samples[i], state.getGeoNormal()) > 0 && Vector3.dot(samples[i], state.getNormal()) > 0)
                    {
                        LightSample dest = new LightSample();
                        dest.setShadowRay(new Ray(state.getPoint(), samples[i]));
                        dest.getShadowRay().setMax(float.MaxValue);
                        dest.setRadiance(colors[i], colors[i]);
                        dest.traceShadow(state);
                        state.addSample(dest);
                    }
                }
            }
        }

 public void getSamples(ShadingState state)
 {
     if (Vector3.dot(dir, state.getGeoNormal()) < 0 && Vector3.dot(dir, state.getNormal()) < 0)
     {
         // project point onto source plane
         float x = state.getPoint().x - src.x;
         float y = state.getPoint().y - src.y;
         float z = state.getPoint().z - src.z;
         float t = ((x * dir.x) + (y * dir.y) + (z * dir.z));
         if (t >= 0.0)
         {
             x -= (t * dir.x);
             y -= (t * dir.y);
             z -= (t * dir.z);
             if (((x * x) + (y * y) + (z * z)) <= r2)
             {
                 Point3 p = new Point3();
                 p.x = src.x + x;
                 p.y = src.y + y;
                 p.z = src.z + z;
                 LightSample dest = new LightSample();
                 dest.setShadowRay(new Ray(state.getPoint(), p));
                 dest.setRadiance(radiance, radiance);
                 dest.traceShadow(state);
                 state.addSample(dest);
             }
         }
     }
 }

//.........这里部分代码省略.........
                Vector3 h = new Vector3();
                h.x = p2.x - dot * p0.x;
                h.y = p2.y - dot * p0.y;
                h.z = p2.z - dot * p0.z;
                float hlen = h.Length();
                if (hlen > 1e-6f)
                    h.div(hlen);
                else
                    return;
                Vector3 n0 = Vector3.cross(p0, p1, new Vector3());
                float len0 = n0.Length();
                if (len0 > 1e-6f)
                    n0.div(len0);
                else
                    return;
                Vector3 n1 = Vector3.cross(p1, p2, new Vector3());
                float len1 = n1.Length();
                if (len1 > 1e-6f)
                    n1.div(len1);
                else
                    return;
                Vector3 n2 = Vector3.cross(p2, p0, new Vector3());
                float len2 = n2.Length();
                if (len2 > 1e-6f)
                    n2.div(len2);
                else
                    return;

                float cosAlpha = MathUtils.clamp(-Vector3.dot(n2, n0), -1.0f, 1.0f);
                float cosBeta = MathUtils.clamp(-Vector3.dot(n0, n1), -1.0f, 1.0f);
                float cosGamma = MathUtils.clamp(-Vector3.dot(n1, n2), -1.0f, 1.0f);

                float alpha = (float)Math.Acos(cosAlpha);
                float beta = (float)Math.Acos(cosBeta);
                float gamma = (float)Math.Acos(cosGamma);

                float area = alpha + beta + gamma - (float)Math.PI;

                float cosC = MathUtils.clamp(Vector3.dot(p0, p1), -1.0f, 1.0f);
                float salpha = (float)Math.Sin(alpha);
                float product = salpha * cosC;

                // use lower sampling depth for diffuse bounces
                int samples = state.getDiffuseDepth() > 0 ? 1 : meshlight.numSamples;
                Color c = Color.mul(area / samples, meshlight.radiance);
                for (int i = 0; i < samples; i++)
                {
                    // random offset on unit square
                    double randX = state.getRandom(i, 0, samples);
                    double randY = state.getRandom(i, 1, samples);

                    float phi = (float)randX * area - alpha + (float)Math.PI;
                    float sinPhi = (float)Math.Sin(phi);
                    float cosPhi = (float)Math.Cos(phi);

                    float u = cosPhi + cosAlpha;
                    float v = sinPhi - product;

                    float q = (-v + cosAlpha * (cosPhi * -v + sinPhi * u)) / (salpha * (sinPhi * -v - cosPhi * u));
                    float q1 = 1.0f - q * q;
                    if (q1 < 0.0f)
                        q1 = 0.0f;

                    float sqrtq1 = (float)Math.Sqrt(q1);
                    float ncx = q * p0.x + sqrtq1 * h.x;
                    float ncy = q * p0.y + sqrtq1 * h.y;
                    float ncz = q * p0.z + sqrtq1 * h.z;
                    dot = p1.dot(ncx, ncy, ncz);
                    float z = 1.0f - (float)randY * (1.0f - dot);
                    float z1 = 1.0f - z * z;
                    if (z1 < 0.0f)
                        z1 = 0.0f;
                    Vector3 nd = new Vector3();
                    nd.x = ncx - dot * p1.x;
                    nd.y = ncy - dot * p1.y;
                    nd.z = ncz - dot * p1.z;
                    nd.normalize();
                    float sqrtz1 = (float)Math.Sqrt(z1);
                    Vector3 result = new Vector3();
                    result.x = z * p1.x + sqrtz1 * nd.x;
                    result.y = z * p1.y + sqrtz1 * nd.y;
                    result.z = z * p1.z + sqrtz1 * nd.z;

                    // make sure the sample is in the right hemisphere - facing in
                    // the right direction
                    if (Vector3.dot(result, n) > 0 && Vector3.dot(result, state.getGeoNormal()) > 0 && Vector3.dot(result, ng) < 0)
                    {
                        // compute intersection with triangle (if any)
                        Ray shadowRay = new Ray(state.getPoint(), result);
                        if (!intersectTriangleKensler(shadowRay))
                            continue;
                        LightSample dest = new LightSample();
                        dest.setShadowRay(shadowRay);
                        // prepare sample
                        dest.setRadiance(c, c);
                        dest.traceShadow(state);
                        state.addSample(dest);
                    }
                }
            }

        public void getSamples(ShadingState state)
        {
            if (getNumSamples() <= 0)
                return;
            Vector3 wc = Point3.sub(center, state.getPoint(), new Vector3());
            float l2 = wc.LengthSquared();
            if (l2 <= r2)
                return; // inside the sphere?
            // top of the sphere as viewed from the current shading point
            float topX = wc.x + state.getNormal().x * radius;
            float topY = wc.y + state.getNormal().y * radius;
            float topZ = wc.z + state.getNormal().z * radius;
            if (state.getNormal().dot(topX, topY, topZ) <= 0)
                return; // top of the sphere is below the horizon
            float cosThetaMax = (float)Math.Sqrt(Math.Max(0, 1 - r2 / Vector3.dot(wc, wc)));
            OrthoNormalBasis basis = OrthoNormalBasis.makeFromW(wc);
            int samples = state.getDiffuseDepth() > 0 ? 1 : getNumSamples();
            float scale = (float)(2 * Math.PI * (1 - cosThetaMax));
            Color c = Color.mul(scale / samples, radiance);
            for (int i = 0; i < samples; i++)
            {
                // random offset on unit square
                double randX = state.getRandom(i, 0, samples);
                double randY = state.getRandom(i, 1, samples);

                // cone sampling
                double cosTheta = (1 - randX) * cosThetaMax + randX;
                double sinTheta = Math.Sqrt(1 - cosTheta * cosTheta);
                double phi = randY * 2 * Math.PI;
                Vector3 dir = new Vector3((float)(Math.Cos(phi) * sinTheta), (float)(Math.Sin(phi) * sinTheta), (float)cosTheta);
                basis.transform(dir);

                // check that the direction of the sample is the same as the
                // normal
                float cosNx = Vector3.dot(dir, state.getNormal());
                if (cosNx <= 0)
                    continue;

                float ocx = state.getPoint().x - center.x;
                float ocy = state.getPoint().y - center.y;
                float ocz = state.getPoint().z - center.z;
                float qa = Vector3.dot(dir, dir);
                float qb = 2 * ((dir.x * ocx) + (dir.y * ocy) + (dir.z * ocz));
                float qc = ((ocx * ocx) + (ocy * ocy) + (ocz * ocz)) - r2;
                double[] t = Solvers.solveQuadric(qa, qb, qc);
                if (t == null)
                    continue;
                LightSample dest = new LightSample();
                // compute shadow ray to the sampled point
                dest.setShadowRay(new Ray(state.getPoint(), dir));
                // FIXME: arbitrary bias, should handle as in other places
                dest.getShadowRay().setMax((float)t[0] - 1e-3f);
                // prepare sample
                dest.setRadiance(c, c);
                dest.traceShadow(state);
                state.addSample(dest);
            }
        }