hi
My chasecam is following my ship nicely. But there is two problems:
1. The distance between cam and ship is relative to the speed of the ship, it shouldnt be (it should be "normal" space-chase-cam)
2. The cam moves a bit jittery.
it is originally thought as a 360 degree rotating camera, with zoom but you can pass your ship's getRotation() angles to it each frame to recenter camera behind ship.
Sorry, I misunderstood the problem 1 and thought that constant distance was the goal.
this camera follows smoothly and will roll with the target
it can be altered to not roll (uncomment the "setUpVector()" line near the end)
it follows target rotation changes instantly, but distance changes take time and the time can be set with internal variable "moveSpeed" (between 0.0 and 1.0 float)
//I3rdPersonCam.h 3rd Person chase camera for Irrlicht 3D 1.1
// version 0.2
#include <irrlicht.h>
using namespace irr;
using namespace irr::core;
using namespace irr::scene;
// 1. create I3rdPersonCam object;
// 2. attach a CameraSceneNode with attachCamera()
// 3. Set a target with setTarget()
// 4. call modOrientation(pan, tilt, zoom) or setOrientation(pan, tilt, zoom) to set relative position camera
// 5. call updatePosition() to apply new Position data
// 6. repeat 4 and 5 as needed
// you might be better off reading the code for information.
class I3rdPersonCam{
public:
float camPan;
float camTilt;
float camZoom;
float maxZoom;
float moveSpeed;
ICameraSceneNode* cam;
ISceneNode* camTarget;
vector3df offset;
I3rdPersonCam(){
camPan=0;
camTilt=45;
camZoom=14;
maxZoom=250;
moveSpeed=0.06; //should be less than or equal to 1
}
void setTarget(ISceneNode *newTarget){
camTarget=newTarget;
}
void setOffset(vector3df newOffset){
offset=newOffset;
}
void attachCamera(ICameraSceneNode *camtoattach){
cam=camtoattach;
}
void modOrientation(float pan1,float tilt1,float zoom1){
camPan=camPan+pan1;
camTilt=camTilt+tilt1;
camZoom=camZoom+zoom1;
if(camPan>360)camPan=camPan-360;
if(camPan<-360)camPan=camPan+360;
if(camTilt>89)camTilt=89;
if(camTilt<-89)camTilt=-89;
if(camZoom>maxZoom)camZoom=maxZoom;
if(camZoom<0)camZoom=0;
}
void setOrientation(float pan1,float tilt1,float zoom1){
camPan=pan1;
camTilt=tilt1;
camZoom=zoom1;
}
void updatePosition()
{
vector3df CPosVector;
vector3df NewCamLocation;
vector3df Target1;
vector3df CPos;
CPos=cam->getPosition();
matrix4 m1;
vector3df campos;
vector3df Upvect1=vector3df(0,1,0);
m1.setRotationDegrees(camTarget->getRotation());
m1.transformVect(Upvect1);
cam->setUpVector(Upvect1);
//CamPan==0 places camera behind Model--- CamPan range 0-360
//camTilt inputs should be between -89 and +89
CPosVector.X=cos((camPan+180)*PI/180)*sin((camTilt+90)*PI/180);
CPosVector.Y=cos((camTilt+90)*PI/180);
CPosVector.Z=sin((camPan+180)*PI/180)*sin((camTilt+90)*PI/180);
matrix4 m2;
m2.setRotationDegrees(camTarget->getRotation());
m2.transformVect(CPosVector);
Target1=camTarget->getPosition()+offset;
NewCamLocation.X=Target1.X+CPosVector.X*camZoom;
NewCamLocation.Y=Target1.Y+CPosVector.Y*camZoom;
NewCamLocation.Z=Target1.Z+CPosVector.Z*camZoom;
vector3df diff1;
diff1=NewCamLocation-CPos;
NewCamLocation.X=CPos.X+diff1.X*moveSpeed;
NewCamLocation.Y=CPos.Y+diff1.Y*moveSpeed;
NewCamLocation.Z=CPos.Z+diff1.Z*moveSpeed;
cam->setPosition(NewCamLocation);
//cam->setUpVector(vector3df(0,1,0));
cam->setTarget(vector3df(Target1));
cam->updateAbsolutePosition();
}
};
This camera follows a walking object very well and tries to stay a set distance and flies to that set distance at a speed based on how far from the distance it is so farther away = faster flight
thanks for the code.
i use cam.setOrientation(0,-10,30);
the cam is smoother so thats nice, BUT:
this cam has the same problem i described with my camera: if the velocity of the craft increases, so does the distance between cam and craft. The cam should "catch up" with its desired position" behind the craft. If i double the speed of the craft, the distance between cam and ship should NOT be double (as speed changes, this distance should temporalily change, but as stated the cam should catch up with its desired position).
This is a classic chasecam, but no code eve found or written manages to do this without pendelum movement.
In my test with this camera the camera does catch up with a walking model, as a ship is faster, you may need to adjust the move speed to a higher value maybe 0.5f so that the camera travels faster.
the move speed is not reay a speed at all but a fraction of the distance measured between camera location and desired location which is traveled each frame
if camera is 1000 units behind and needs to be 100 units behind then a moveSpeed of 0.5f will bring the camera 450 units closer to target position
but if the camera is closer to the target position it moves slower
you must reference the moveSpeed variable directly like this:
I3rdPersonCam My3rdCam1;
My3rdCam1.moveSpeed= 0.5f
if you haven't done this that may be why the camera lags so far back because the default is moveSpeed=0.06f which is very slow
moveSpeed=1.0f is the limit which makes the camera not chase but keeps it at the exact distance
note: this camera never reaches the exact target distance, but aproaches the target distance at a percentage of the distance between which is measured each frame
what you describe is what i want, but it doesnt work that way. i use
I3rdPersonCam(){
camPan=0;
camTilt=45;
camZoom=14;
maxZoom=250;
moveSpeed=0.02; //should be less than or equal to 1
}
and increasing the speed does only lower the scale of the difference in distance in different, the cam still change distance (it does NOT catch up with a fast plane). See a compiled version of it here:
since this camera never really reaches the target distance (only approaches that distance) you may still get some lag at high speeds since acceleration must occur before high speed although if you constantly adjust the move speed with a ratio of (airspeed:maximum airspeed) you may alter this effect
this camera works really good with a stoppable object since it has time to catch up, but for constantly moving objects you may need to have a higher moveSpeed=0.5f
or adjust move speed based on airspeed
Im not following you. Did you see my demo?
I dont need to change speed for this cam to not work at constant distance. If i raise speed and keep it constant at high speed the distance is larger then if i hold a constant low speed.
i try things like
cam.moveSpeed=myCraft.vel/20+0.02;
but this doesnt work very well. It still makes the cam stay at different distance depending on speed, and changes the amount of "chase effect" at higher speeds. It seems if i let the moveSpeed increase enough to keep up with planes going at higher speed, it will be fast enough to remove the "chase effect", thus being a simple static behind camera.
So my question remains:
Is there no way to do a chasecam? I know they have it in a lot of games...
Im beginning to really loose my interest in 3d game making... Theres just to much hassle to do the most basic thing. And a lot of experienced 3d programmers cant do it either so it seems theres a lot of studying to do to even get enywhere... I might stick to my good old 2d games. Where i spend time coming up with ideas and implementating them instead of spending time asking people on the forums why stuff doesnt work the way they are supposed to.
