public static Matrix4By4 Transpose(Matrix4By4 matrix)
{
Vector firstRow = new Vector(matrix.m.v1.x, matrix.m.v2.x, matrix.m.v3.x);
Vector secondRow = new Vector(matrix.m.v1.y, matrix.m.v2.y, matrix.m.v3.y);
Vector thirdRow = new Vector(matrix.m.v1.z, matrix.m.v2.z, matrix.m.v3.z);
return(new Matrix4By4(new Matrix(firstRow, secondRow, thirdRow), new Vector(0, 0, 0)));
}
public static Matrix4By4 ZRotation(double rotationAngleThroughZAxis)
{
Matrix4By4 rm =
new Matrix4By4(new Matrix(
new Vector(Math.Cos(Algebra.convertToRad(rotationAngleThroughZAxis)), Math.Sin(Algebra.convertToRad(rotationAngleThroughZAxis)), 0),
new Vector((-1) * Math.Sin(Algebra.convertToRad(rotationAngleThroughZAxis)), Math.Cos(Algebra.convertToRad(rotationAngleThroughZAxis)), 0),
new Vector(0, 0, 1)),
new Vector());
return(rm);
}
public void AddRotationThroughAllAxisToTransformationMatrix(double rotationAngleThroughXAxis, double rotationAngleThroughYAxis, double rotaionAngleThroughZAxis)
{
transformMatrix = Matrix4By4.ZRotation(rotaionAngleThroughZAxis) * Matrix4By4.YRotation(rotationAngleThroughYAxis) * Matrix4By4.XRotation(rotationAngleThroughXAxis) * transformMatrix;
inverseTransformMatrix *= Matrix4By4.XRotation(-rotationAngleThroughXAxis) * Matrix4By4.YRotation(-rotationAngleThroughYAxis) * Matrix4By4.ZRotation(-rotaionAngleThroughZAxis);
}
public void AddScaleToTransformationMatrix(Vector scale)
{
transformMatrix = new Matrix4By4(new Matrix(new Vector(scale.x, 0, 0), new Vector(0, scale.y, 0), new Vector(0, 0, scale.z)), new Vector());
inverseTransformMatrix *= new Matrix4By4(new Matrix(new Vector((1 / scale.x), 0, 0), new Vector(0, (1 / scale.y), 0), new Vector(0, 0, (1 / scale.z))), new Vector());
}
/*
* // to find the reflected ray after reflection
* public virtual Vector ReflectedRay(Vector direction, Vector normal) {
* Vector reflectionRay = direction - 2 * (normal * direction) * normal;
* return reflectionRay;
* }*/
public void AddTranslationToTranformationMatrix(Vector translate)
{
transformMatrix = new Matrix4By4(new Matrix(), translate) * transformMatrix;
inverseTransformMatrix *= new Matrix4By4(new Matrix(), (-1) * translate);
}
SColor TraceRay(Ray ray, Scene scene, int rayDepth)
{
int maximumNumberOfReflections = 10;
if (rayDepth >= maximumNumberOfReflections)
{
return(new SColor(0, 0, 0, 0));
}
SColor shapeColor = new SColor();
SColor reflectionColor = new SColor();
SColor averageReflectionColor = new SColor();
Shape closestShape = scene.shapes[0]; // rendering multiple objects so searching for the closest shape to render
double closestT = double.MaxValue; // shape which has closest T need to be rendered at first
foreach (Shape shape in scene.shapes)
{
//transforming the ray origin along with the given tranformation matrices
// origin is transformed like the point tranformation whereas ray direction is transformed like the vector transformation
Vector newOrigin = FindNewPoint(shape.inverseTransformMatrix, ray.origin);
Vector newDirection = (shape.inverseTransformMatrix * ray.direction).Normalize();
double t = shape.DoesIntersect(newOrigin, newDirection); // passing transformed origin and transformed direction
if ((t < closestT) && (t >= 0.0001))
{
closestT = t;
closestShape = shape;
}
}
Vector closeOrigin = FindNewPoint(closestShape.inverseTransformMatrix, ray.origin);
Vector closeDirection = (closestShape.inverseTransformMatrix * ray.direction).Normalize();
if (closestShape.DoesIntersect(closeOrigin, closeDirection) >= 0) // checking whether the ray hits the sphere or not
{
Vector point = closeOrigin + (closeDirection * closestT); // point of intersection
SColor color = closestShape.material.ColorAtPoint(point);
double ambient = closestShape.material.ambient;
double specularCoefficient = closestShape.material.specularCoefficient;
SColor lightContribution = new SColor();
//transforming the point of intersection according to the transformation matrices
point = FindNewPoint(closestShape.transformMatrix, point);
Vector normal = closestShape.NormalAtPoint(point);
// also transforming the normal of the shapes according to the transformation matrix
normal = Matrix4By4.Transpose(closestShape.inverseTransformMatrix) * normal;
// for multiple lighting
foreach (Light light in scene.lights)
{
// for also checking shadows
Vector shadowRayDirection = (light.location - point).Normalize(); // calculating the direction of the ray of the shadow
// at first assigning inShadow variable boolean value false so that we can check whether any shape is in shadow or not
bool inShadow = false;
foreach (Shape shape in scene.shapes)
{
//checking whether each shape is in shadow or not
// also checking whether the distance from the point of intersection and the direction of the ray is greater than the ray intersection distance
//transforming the ray origin along with the given tranformation matrices
Vector transformedShadowRayDirection = (shape.inverseTransformMatrix * shadowRayDirection).Normalize();
if (shape.DoesIntersect(point + (normal * 0.5), transformedShadowRayDirection) >= 0 && Math.Abs((light.location - point).Magnitude()) > shape.DoesIntersect(position, closeDirection))
{
inShadow = true;
break; // giving break point if it's in in shadow
}
}
if (inShadow)
{
continue; // if it's in shadow than continuing that is casting a shadow
}
Vector lightToPoint = point - light.location; // position vector from light to point of intersection
Vector lightDriection = lightToPoint.Normalize(); // and then normalizing it to get the direction of that vector
double cosineAngle = -(lightDriection * normal); // finding the scalar value which gives the light intensity
if (cosineAngle < 0)
{
cosineAngle = 0;
}
// for specular highlight
Vector cameraToIntersectionPoint = (position - point).Normalize();
Vector reflectedRayDirection = (closestShape.material.ReflectedRay(ray.origin, ray.direction, closestShape).direction).Normalize();
//averageReflectionColor = reflectionColor * (1 / rayDepth);
//color = averageReflectionColor + color;
double specularFactor = Math.Pow((cameraToIntersectionPoint * reflectedRayDirection), closestShape.material.smoothness);
if (specularFactor < 0)
{
specularFactor = 0;
}
if (cosineAngle >= 0 || specularFactor >= 0)
{
lightContribution = lightContribution + (light.lightColor * color * (cosineAngle * closestShape.material.diffuseCoefficient + specularFactor * closestShape.material.specularCoefficient) * light.Intensity);
}
}
/*
* if (rayDepth < maximumNumberOfReflections)
* {
* Ray reflectedRay = closestShape.material.ReflectedRay(closeOrigin, closeDirection, closestShape);
* reflectionColor = TraceRay(reflectedRay, scene, rayDepth + 1); // recursive method
* }
*/
shapeColor = lightContribution + (color * ambient);
}
return(shapeColor + closestShape.material.reflectionCoefficient * reflectionColor);
}
//creating the method for multiplying matrix 4by4 and point of intersection
Vector FindNewPoint(Matrix4By4 matrix, Vector point)
{
Vector vector1 = matrix * point;
return(vector1 + matrix.v1);
}