Move an object in the direction of a bezier curve?
- by Sent1nel
I have an object with which I would like to make follow a bezier curve and am a little lost right now as to how to make it do that based on time rather than the points that make up the curve.
.::Current System::.
Each object in my scene graph is made from position, rotation and scale vectors. These vectors are used to form their corresponding matrices: scale, rotation and translation. Which are then multiplied in that order to form the local transform matrix.
A world transform (Usually the identity matrix) is then multiplied against the local matrix transform.
class CObject
{
public:
// Local transform functions
Matrix4f GetLocalTransform() const;
void SetPosition(const Vector3f& pos);
void SetRotation(const Vector3f& rot);
void SetScale(const Vector3f& scale);
// Local transform
Matrix4f m_local;
Vector3f m_localPostion;
Vector3f m_localRotation; // rotation in degrees (xrot, yrot, zrot)
Vector3f m_localScale;
}
Matrix4f CObject::GetLocalTransform()
{
Matrix4f out(Matrix4f::IDENTITY);
Matrix4f scale(), rotation(), translation();
scale.SetScale(m_localScale);
rotation.SetRotationDegrees(m_localRotation);
translation.SetTranslation(m_localTranslation);
out = scale * rotation * translation;
}
The big question I have are
1) How do I orientate my object to face the tangent of the Bezier curve?
2) How do I move that object along the curve without just setting objects position to that of a point on the bezier cuve?
Heres an overview of the function thus far
void CNodeControllerPieceWise::AnimateNode(CObject* pSpatial, double deltaTime)
{
// Get object latest pos.
Vector3f posDelta = pSpatial->GetWorldTransform().GetTranslation();
// Get postion on curve
Vector3f pos = curve.GetPosition(m_t);
// Get tangent of curve
Vector3f tangent = curve.GetFirstDerivative(m_t);
}
Edit: sorry its not very clear. I've been working on this for ages and its making my brain turn to mush.
I want the object to be attached to the curve and face the direction of the curve.
As for movement, I want to object to follow the curve based on the time this way it creates smooth movement throughout the curve.
