C++ (Cpp) vector3::Cross Examples

Programming Language: C++ (Cpp)

Class/Type: vector3

Method/Function: Cross

Examples at hotexamples.com: 2

The Vector3 cross function is a mathematical operation used to compute the cross product of two vectors. It returns a new vector that is perpendicular to the two input vectors and has a magnitude equal to the product of their magnitudes times the sine of the angle between them.

Example 1: Suppose we have two vectors a = (1, 2, 3) and b = (4, 5, 6). To compute their cross product, we can write:

#include 
#include 
#include 

using namespace std;

struct Vector3 {
    double x, y, z;
};

Vector3 cross(Vector3 a, Vector3 b) {
    Vector3 result;
    result.x = a.y * b.z - a.z * b.y;
    result.y = a.z * b.x - a.x * b.z;
    result.z = a.x * b.y - a.y * b.x;
    return result;
}

int main() {
    Vector3 a = {1, 2, 3};
    Vector3 b = {4, 5, 6};
    Vector3 c = cross(a, b);
    cout << "(" << c.x << ", " << c.y << ", " << c.z << ")" << endl;
    return 0;
}

This program will output the result of the cross product: (-3, 6, -3).

Example 2: Another example is to compute the normal vector of a plane defined by three points. Suppose we have the points p1 = (-1, 2, 3), p2 = (4, 5, 6), and p3 = (7, 8, -1). To compute the normal vector of the plane passing through these points, we can write:

#include 
#include 
#include 

using namespace std;

struct Vector3 {
    double x, y, z;
};

Vector3 cross(Vector3 a, Vector3 b) {
    Vector3 result;
    result.x = a.y * b.z - a.z * b.y;
    result.y = a.z * b.x - a.x * b.z;
    result.z = a.x * b.y - a.y * b.x;
    return result;
}

int main() {
    Vector3 p1 = {-1, 2, 3};
    Vector3 p2 = {4, 5, 6};
    Vector3 p3 = {7, 8, -1};
    Vector3 a = {p2.x - p1.x, p2.y - p1.y, p2.z - p1.z};
    Vector3 b = {p3.x - p1.x, p3.y - p1.y, p3.z - p1.z};
    Vector3 n = cross(a, b);
    cout << "The normal vector of the plane is: (" << n.x << ", " << n.y << ", " << n.z << ")" << endl;
    return 0;
}

This program will output the normal vector of the plane passing through the three points: (-29, -15, -13). The Vector3 cross function is commonly used in 3D computer graphics and physics simulations. It is part of the glm library, which is a header-only C++ math library for graphics applications.

C++ (Cpp) vector3::Cross - 2 examples found. These are the top rated real world C++ (Cpp) examples of vector3::Cross extracted from open source projects. You can rate examples to help us improve the quality of examples.

Frequently Used Methods

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z(30)

y(30)

x(30)

normalize(10)

getX(3)

normalized(3)

getZ(3)

getY(3)

length(3)

Length(3)

Cross(2)

cross(2)

print(2)

Dot(2)

Set(2)

dot(2)

norm(1)

IsApprox(1)

xy(1)

projected(1)

angle(1)

normal(1)

getAs4Values(1)

mult(1)

mod(1)

magnitude_within_32_bits(1)

length_squared(1)

length_sq(1)

get_z(1)

get_y(1)

get_x(1)

get_orthogonal(1)

distSq(1)

manhattan_length(1)

Example #1

Show file

File: re_math.cpp Project: JuzzWuzz/defter

//-------------------------------------------------------------------------
// CREATE LOOK AT creates a look-at matrix for use as a view matrix
matrix4
create_look_at(vector3 &camera, vector3 &target, vector3 &up){
	// Builds a look-at style view matrix.
	// This is essentially the same matrix used by gluLookAt().

	matrix4 out;

	vector3 zAxis = camera - target;
	zAxis.Normalize();

	vector3 xAxis = up.Cross(zAxis);
	xAxis.Normalize();

	vector3 yAxis = zAxis.Cross(xAxis);
	yAxis.Normalize();

	out[0] = xAxis.x;
	out[4] = xAxis.y;
	out[8] = xAxis.z;
	out[12] = -xAxis.Dot(camera);

	out[1] = yAxis.x;
	out[5] = yAxis.y;
	out[9] = yAxis.z;
	out[13] = -yAxis.Dot(camera);

	out[2] = zAxis.x;
	out[6] = zAxis.y;
	out[10] = zAxis.z;
	out[14] = -zAxis.Dot(camera);

	out[3] = 0.0f;
	out[7] = 0.0f;
	out[11] = 0.0f;
	out[15] = 1.0f;

	return out;
}

Example #2

Show file

File: vector.cpp Project: lsempe/uipg

vector3 vector3::Cross(const vector3& v1, const vector3& v2)
{
	return v1.Cross(v2);
}