C++ GfMatrix4d类代码示例

GlfSimpleLight
HdStLight::_ApproximateAreaLight(SdfPath const &id, 
                                 HdSceneDelegate *sceneDelegate)
{
    // Get the color of the light
    GfVec3f hdc = sceneDelegate->GetLightParamValue(id, HdStLightTokens->color)
            .Get<GfVec3f>();

    // Extract intensity
    float intensity = 
        sceneDelegate->GetLightParamValue(id, HdLightTokens->intensity)
            .Get<float>();

    // Extract the exposure of the light
    float exposure = 
        sceneDelegate->GetLightParamValue(id, HdLightTokens->exposure)
            .Get<float>();
    intensity *= powf(2.0f, GfClamp(exposure, -50.0f, 50.0f));

    // Calculate the final color of the light
    GfVec4f c(hdc[0]*intensity, hdc[1]*intensity, hdc[2]*intensity, 1.0f); 

    // Get the transform of the light
    GfMatrix4d transform = _params[HdTokens->transform].Get<GfMatrix4d>();
    GfVec3d hdp = transform.ExtractTranslation();
    GfVec4f p = GfVec4f(hdp[0], hdp[1], hdp[2], 1.0f);

    // Create the Glf Simple Light object that will be used by the rest
    // of the pipeline. No support for shadows for this translated light.
    GlfSimpleLight l;
    l.SetPosition(p);
    l.SetDiffuse(c);
    l.SetHasShadow(false);
    return l;
}

GfMatrix4d
GfFrustum::ComputeViewMatrix() const
{
    GfMatrix4d m;
    m.SetLookAt(_position, _rotation);
    return m;
}

vector<GfVec3d>
GfFrustum::ComputeCornersAtDistance(double d) const
{
    const GfVec2d &winMin = _window.GetMin();
    const GfVec2d &winMax = _window.GetMax();

    vector<GfVec3d> corners;
    corners.reserve(4);

    if (_projectionType == Perspective) {
        // Similar to ComputeCorners
        corners.push_back(GfVec3d(d * winMin[0], d * winMin[1], -d));
        corners.push_back(GfVec3d(d * winMax[0], d * winMin[1], -d));
        corners.push_back(GfVec3d(d * winMin[0], d * winMax[1], -d));
        corners.push_back(GfVec3d(d * winMax[0], d * winMax[1], -d));
    }
    else {
        corners.push_back(GfVec3d(winMin[0], winMin[1], -d));
        corners.push_back(GfVec3d(winMax[0], winMin[1], -d));
        corners.push_back(GfVec3d(winMin[0], winMax[1], -d));
        corners.push_back(GfVec3d(winMax[0], winMax[1], -d));
    }

    // Each corner is then transformed into world space by the inverse
    // of the view matrix.
    const GfMatrix4d m = ComputeViewInverse();
    for (int i = 0; i < 4; i++)
        corners[i] = m.Transform(corners[i]);

    return corners;
}

GfMatrix4d
Hdx_UnitTestGLDrawing::GetViewMatrix() const
{
    GfMatrix4d viewMatrix;
    viewMatrix.SetIdentity();
    // rotate from z-up to y-up
    viewMatrix *= GfMatrix4d().SetRotate(GfRotation(GfVec3d(1.0,0.0,0.0), -90.0));
    viewMatrix *= GfMatrix4d().SetRotate(GfRotation(GfVec3d(0, 1, 0), _rotate[1]));
    viewMatrix *= GfMatrix4d().SetRotate(GfRotation(GfVec3d(1, 0, 0), _rotate[0]));
    viewMatrix *= GfMatrix4d().SetTranslate(GfVec3d(_translate[0], _translate[1], _translate[2]));

    return viewMatrix;
}

/* virtual */
void
HdSt_TestLightingShader::SetCamera(GfMatrix4d const &worldToViewMatrix,
                                 GfMatrix4d const &projectionMatrix)
{
    for (int i = 0; i < 2; ++i) {
        _lights[i].eyeDir
            = worldToViewMatrix.TransformDir(_lights[i].dir).GetNormalized();
    }
}

void
GfFrustum::SetPositionAndRotationFromMatrix(
    const GfMatrix4d &camToWorldXf)
{
    // First conform matrix to be...
    GfMatrix4d conformedXf = camToWorldXf;
    // ... right handed
    if (!conformedXf.IsRightHanded()) {
        static GfMatrix4d flip(GfVec4d(-1.0, 1.0, 1.0, 1.0));
        conformedXf = flip * conformedXf;
    }

    // ... and orthonormal
    conformedXf.Orthonormalize();

    SetRotation(conformedXf.ExtractRotation());
    SetPosition(conformedXf.ExtractTranslation());
}

// Assumes rotationOrder is XYZ.
static void
_RotMatToRotXYZ(
    const GfMatrix4d &rotMat,
    GfVec3f *rotXYZ)
{
    GfRotation rot = rotMat.ExtractRotation();
    GfVec3d angles = rot.Decompose(GfVec3d::ZAxis(),
                                   GfVec3d::YAxis(),
                                   GfVec3d::XAxis());
    *rotXYZ = GfVec3f(angles[2], angles[1], angles[0]);
}

GfPlane &
GfPlane::Transform(const GfMatrix4d &matrix) 
{
    // Compute the point on the plane along the normal from the origin.
    GfVec3d pointOnPlane = _distance * _normal;

    // Transform the plane normal by the adjoint of the matrix to get
    // the new normal.  The adjoint (inverse transpose) is used to
    // multiply normals so they are not scaled incorrectly.
    GfMatrix4d adjoint = matrix.GetInverse().GetTranspose();
    _normal = adjoint.TransformDir(_normal).GetNormalized();

    // Transform the point on the plane by the matrix.
    pointOnPlane = matrix.Transform(pointOnPlane);

    // The new distance is the projected distance of the vector to the
    // transformed point onto the (unit) transformed normal. This is
    // just a dot product.
    _distance = GfDot(pointOnPlane, _normal);

    return *this;
}

// Assumes rotationOrder is XYZ.
static void
_RotMatToRotTriplet(
    const GfMatrix4d &rotMat,
    GfVec3d *rotTriplet)
{
    GfRotation rot = rotMat.ExtractRotation();
    GfVec3d angles = rot.Decompose(GfVec3d::ZAxis(),
                                   GfVec3d::YAxis(),
                                   GfVec3d::XAxis());
    (*rotTriplet)[0] = angles[2];
    (*rotTriplet)[1] = angles[1];
    (*rotTriplet)[2] = angles[0];
}

static void
_MatrixToVectorsWithPivotInvariant(
    const GfMatrix4d &m,
    const GfVec3d pivotPosition,
    const GfVec3d pivotOrientation,
    GfVec3d *translation, 
    GfVec3d *rotation, 
    GfVec3d *scale, 
    GfVec3d *scaleOrientation) 
{

    GfMatrix3d pivotOrientMat = _EulerXYZToMatrix3d(pivotOrientation);

    GfMatrix4d pp    = GfMatrix4d(1.0).SetTranslate( pivotPosition);
    GfMatrix4d ppInv = GfMatrix4d(1.0).SetTranslate(-pivotPosition);
    GfMatrix4d po    = GfMatrix4d(1.0).SetRotate(pivotOrientMat);
    GfMatrix4d poInv = GfMatrix4d(1.0).SetRotate(pivotOrientMat.GetInverse());

    GfMatrix4d factorMe = po * pp * m * ppInv;

    GfMatrix4d scaleOrientMat, factoredRotMat, perspMat;

    factorMe.Factor(&scaleOrientMat, scale, &factoredRotMat, 
                    translation, &perspMat);

    GfMatrix4d rotMat = factoredRotMat * poInv;

    if(not rotMat.Orthonormalize(/* issueWarning */ false))
        TF_WARN("Failed to orthonormalize rotMat.");

    _RotMatToRotTriplet(rotMat, rotation);

    if(not scaleOrientMat.Orthonormalize(/* issueWarning */ false))
        TF_WARN("Failed to orthonormalize scaleOrientMat.");

    _RotMatToRotTriplet(scaleOrientMat, scaleOrientation);
}

static
bool
_IsMatrixIdentity(const GfMatrix4d& matrix)
{
    const GfMatrix4d IDENTITY(1.0);
    const double TOLERANCE = 1e-6;

    if (GfIsClose(matrix.GetRow(0), IDENTITY.GetRow(0), TOLERANCE)      &&
            GfIsClose(matrix.GetRow(1), IDENTITY.GetRow(1), TOLERANCE)  &&
            GfIsClose(matrix.GetRow(2), IDENTITY.GetRow(2), TOLERANCE)  &&
            GfIsClose(matrix.GetRow(3), IDENTITY.GetRow(3), TOLERANCE)) {
        return true;
    }

    return false;
}

static void
_ConvertMatrixToComponents(const GfMatrix4d &matrix, 
                           GfVec3d *translation, 
                           GfVec3f *rotation,
                           GfVec3f *scale)
{
    GfMatrix4d rotMat(1.0);
    GfVec3d doubleScale(1.0);
    GfMatrix4d scaleOrientMatUnused, perspMatUnused;
    matrix.Factor(&scaleOrientMatUnused, &doubleScale, &rotMat, 
                    translation, &perspMatUnused);

    *scale = GfVec3f(doubleScale[0], doubleScale[1], doubleScale[2]);

    if (!rotMat.Orthonormalize(/* issueWarning */ false))
        TF_WARN("Failed to orthonormalize rotation matrix.");

    _RotMatToRotXYZ(rotMat, rotation);
}

//.........这里部分代码省略.........
    //
    UsdAttribute positionsAttr = instancer.GetPositionsAttr();
    if (!positionsAttr.HasValue())
    {
        _LogAndSetError(instancerAttrMap, "Instancer has no positions");
        return;
    }

    //
    // Compute instance transform matrices.
    //

    const double timeCodesPerSecond = stage->GetTimeCodesPerSecond();

    // Gather frame-relative sample times and add them to the current time to
    // generate absolute sample times.
    //
    const std::vector<double> &motionSampleTimes =
        data.GetMotionSampleTimes(positionsAttr);
    const size_t sampleCount = motionSampleTimes.size();
    std::vector<UsdTimeCode> sampleTimes(sampleCount);
    for (size_t a = 0; a < sampleCount; ++a)
    {
        sampleTimes[a] = UsdTimeCode(currentTime + motionSampleTimes[a]);
    }

    // Get velocityScale from the opArgs.
    //
    float velocityScale = FnKat::FloatAttribute(
        inputAttrs.getChildByName("opArgs.velocityScale")).getValue(1.0f, false);

    // XXX Replace with UsdGeomPointInstancer::ComputeInstanceTransformsAtTime.
    //
    std::vector<std::vector<GfMatrix4d>> xformSamples(sampleCount);
    const size_t numXformSamples =
        _ComputeInstanceTransformsAtTime(xformSamples, instancer, sampleTimes,
            UsdTimeCode(currentTime), timeCodesPerSecond, numInstances,
            positionsAttr, velocityScale);
    if (numXformSamples == 0) {
        _LogAndSetError(instancerAttrMap, "Could not compute "
                                          "sample/topology-invarying instance "
                                          "transform matrix");
        return;
    }

    //
    // Compute prototype bounds.
    //

    bool aggregateBoundsValid = false;
    std::vector<double> aggregateBounds;

    // XXX Replace with UsdGeomPointInstancer::ComputeExtentAtTime.
    //
    VtVec3fArray aggregateExtent;
    if (_ComputeExtentAtTime(
            aggregateExtent, data.GetUsdInArgs(), xformSamples,
            motionSampleTimes, protoIndices, protoPaths, primCache,
            pruneMaskValues)) {
        aggregateBoundsValid = true;
        aggregateBounds.resize(6);
        aggregateBounds[0] = aggregateExtent[0][0]; // min x
        aggregateBounds[1] = aggregateExtent[1][0]; // max x
        aggregateBounds[2] = aggregateExtent[0][1]; // min y
        aggregateBounds[3] = aggregateExtent[1][1]; // max y
        aggregateBounds[4] = aggregateExtent[0][2]; // min z

void
GlfSimpleLightingContext::SetStateFromOpenGL()
{
    // import classic GL light's parameters into shaded lights
    SetUseLighting(glIsEnabled(GL_LIGHTING));

    GfMatrix4d worldToViewMatrix;
    glGetDoublev(GL_MODELVIEW_MATRIX, worldToViewMatrix.GetArray());
    GfMatrix4d viewToWorldMatrix = worldToViewMatrix.GetInverse();

    GLint nLights = 0;
    glGetIntegerv(GL_MAX_LIGHTS, &nLights);

    GlfSimpleLightVector lights;
    lights.reserve(nLights);

    GlfSimpleLight light;
    for(int i = 0; i < nLights; ++i)
    {
        int lightName = GL_LIGHT0 + i;
        if (glIsEnabled(lightName)) {
            GLfloat position[4], color[4];

            glGetLightfv(lightName, GL_POSITION, position);
            light.SetPosition(GfVec4f(position)*viewToWorldMatrix);
            
            glGetLightfv(lightName, GL_AMBIENT, color);
            light.SetAmbient(GfVec4f(color));
            
            glGetLightfv(lightName, GL_DIFFUSE, color);
            light.SetDiffuse(GfVec4f(color));
            
            glGetLightfv(lightName, GL_SPECULAR, color);
            light.SetSpecular(GfVec4f(color));

            lights.push_back(light);
        }
    }

    SetLights(lights);

    GlfSimpleMaterial material;

    GLfloat color[4], shininess;
    glGetMaterialfv(GL_FRONT, GL_AMBIENT, color);
    material.SetAmbient(GfVec4f(color));
    glGetMaterialfv(GL_FRONT, GL_DIFFUSE, color);
    material.SetDiffuse(GfVec4f(color));
    glGetMaterialfv(GL_FRONT, GL_SPECULAR, color);
    material.SetSpecular(GfVec4f(color));
    glGetMaterialfv(GL_FRONT, GL_EMISSION, color);
    material.SetEmission(GfVec4f(color));
    glGetMaterialfv(GL_FRONT, GL_SHININESS, &shininess);
    // clamp to 0.0001, since pow(0,0) is undefined in GLSL.
    shininess = std::max(0.0001f, shininess);
    material.SetShininess(shininess);

    SetMaterial(material);

    GfVec4f sceneAmbient;
    glGetFloatv(GL_LIGHT_MODEL_AMBIENT, &sceneAmbient[0]);
    SetSceneAmbient(sceneAmbient);
}

GfFrustum &
GfFrustum::Transform(const GfMatrix4d &matrix)
{
    // We'll need the old parameters as we build up the new ones, so, work
    // on a newly instantiated frustum. We'll replace the contents of
    // this frustum with it once we are done. Note that _dirty is true
    // by default, so, there is no need to initialize it here.
    GfFrustum frustum;

    // Copy the projection type
    frustum._projectionType = _projectionType;

    // Transform the position of the frustum
    frustum._position = matrix.Transform(_position);

    // Transform the rotation as follows:
    //   1. build view and direction vectors
    //   2. transform them with the given matrix
    //   3. normalize the vectors and cross them to build an orthonormal frame
    //   4. construct a rotation matrix
    //   5. extract the new rotation from the matrix
    
    // Generate view direction and up vector
    GfVec3d viewDir = ComputeViewDirection();
    GfVec3d upVec   = ComputeUpVector();

    // Transform by matrix
    GfVec3d viewDirPrime = matrix.TransformDir(viewDir);
    GfVec3d upVecPrime = matrix.TransformDir(upVec);

    // Normalize. Save the vec size since it will be used to scale near/far.
    double scale = viewDirPrime.Normalize();
    upVecPrime.Normalize();

    // Cross them to get the third axis. Voila. We have an orthonormal frame.
    GfVec3d viewRightPrime = GfCross(viewDirPrime, upVecPrime);
    viewRightPrime.Normalize();

    // Construct a rotation matrix using the axes.
    //
    //  [ right     0 ]
    //  [ up        1 ]
    //  [ -viewDir  0 ]
    //  [ 0  0   0  1 ]
    GfMatrix4d rotMatrix;
    rotMatrix.SetIdentity();
    // first row
    rotMatrix[0][0] = viewRightPrime[0];
    rotMatrix[0][1] = viewRightPrime[1];
    rotMatrix[0][2] = viewRightPrime[2];

    // second row
    rotMatrix[1][0] = upVecPrime[0];
    rotMatrix[1][1] = upVecPrime[1];
    rotMatrix[1][2] = upVecPrime[2];

    // third row
    rotMatrix[2][0] = -viewDirPrime[0];
    rotMatrix[2][1] = -viewDirPrime[1];
    rotMatrix[2][2] = -viewDirPrime[2];

    // Extract rotation
    frustum._rotation = rotMatrix.ExtractRotation();

    // Since we applied the matrix to the direction vector, we can use
    // its length to find out the scaling that needs to applied to the
    // near and far plane. 
    frustum._nearFar = _nearFar * scale;

    // Use the same length to scale the view distance
    frustum._viewDistance = _viewDistance * scale;

    // Transform the reference plane as follows:
    //
    //   - construct two 3D points that are on the reference plane 
    //     (left/bottom and right/top corner of the reference window) 
    //   - transform the points with the given matrix
    //   - move the window back to one unit from the viewpoint and
    //     extract the 2D coordinates that would form the new reference
    //     window
    //
    //     A note on how we do the last "move" of the reference window:
    //     Using similar triangles and the fact that the reference window
    //     is one unit away from the viewpoint, one can show that it's 
    //     sufficient to divide the x and y components of the transformed
    //     corners by the length of the transformed direction vector.
    //
    //     A 2D diagram helps:
    //
    //                            |
    //                            |
    //               |            |
    //       * ------+------------+
    //      vp       |y1          |
    //                            |
    //       \--d1--/             |y2
    //
    //       \-------d2----------/
    //
    //     So, y1/y2 = d1/d2 ==> y1 = y2 * d1/d2 
//.........这里部分代码省略.........