I want to be able to move a particle in a straight line within a 3D environment but I can't think how to work out the next location based on two points within a 3D space?
I have created a struct which represents a particle which has a location and a next location? Would this be suitable to work out the next location to move too? I know how to initially set the next location using the following method:
// Set particle's direction to a random direction
void setDirection(struct particle *p)
{
float xnm = (p->location.x * -1) - p->velocity;
float xnp = p->location.x + p->velocity;
float ynm = (p->location.y * -1) - p->velocity;
float ynp = p->location.y + p->velocity;
float znm = (p->location.z * -1) - p->velocity;
float znp = p->location.z + p->velocity;
struct point3f nextLocation = { randFloat(xnm, xnp), randFloat(ynm, ynp), randFloat(znm, znp) };
p->nextLocation = nextLocation;
}
The structs I have used are:
// Represents a 3D point
struct point3f
{
float x;
float y;
float z;
};
// Represents a particle
struct particle
{
enum TYPES type;
float radius;
float velocity;
struct point3f location;
struct point3f nextLocation;
struct point3f colour;
};
Am I going about this completely the wrong way?
here's all my code http://pastebin.com/m469f73c2
The other answer is a little mathish, it's actually pretty straight forward.
You need a "Velocity" which you are moving. It also has x, y and z coordinates.
In one time period, to move you just add the x velocity to your x position to get your new x position, repeat for y and z.
On top of that, you can have an "Acceleration" (also x,y,z) For instance, your z acceleration could be gravity, a constant.
Every time period your velocity should be recalcualted in the same way, Call velocity x "vx", so vx should become vx + ax, repeat for y and z (again).
It's been a while since math, but that's how I remember it, pretty straight forward unless you need to keep track of units, then it gets a little more interesting (but still not bad)