Author Topic: 3DS baked textures?  (Read 8599 times)

Offline raft

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Re: 3DS baked textures?
« Reply #15 on: May 10, 2007, 03:12:19 am »
for jumping, if i got you right, by elevation jumping you mean actually translating up your avatar instead of animating mesh upwards..

if that's the case i do use such jumping. after all you cant jump over objects otherway. here is how i do it:

i disable regular gravity calculations during jump. with some kind of position calculator i translate the avatar up using collision checks (there may be an obstacle on top of it) after it reached top position the mechanism reverses to down again using collision checks. this way it can jump over obstacles and even land on them. that position calculator helps calculating desired translations, in up part faster in the beginning, slows down and reaches 0 at top, then in down part getting faster and faster. that gives the gravity effect.

hope this helps
r a f t

Offline ToddMcF2002

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Re: 3DS baked textures?
« Reply #16 on: May 10, 2007, 12:45:11 pm »
I actually implemented it last night - similiar to what you are saying Raft.   However you've reminded me I have to handle head collision.   Here is all the collision code - it essentially checks for a jump offset during its gravity calculation and accounts for the height of the jump.  Depending on the current animation frame I increment or decrement the height offset.  So its the gravity calculation itself that causes the avatar to rise and fall because of the offset.

Also I added a smoothing factor to the Y axis transition where I don't allow anything greater than 7 in either direction.  I did this because if the avatar steps off a small rise the camera jolts to follow the drastic change on the Y plane.  Also, the avatar shouldnt transition on the Y axis instantaneously, that's not gravity!  Seems to work nicely.  I also terminate the jump animation if a plane is encountered.  As an aside - the reason for the "blocking" boolean is because if the user releases the forward motion during a jump the animation wants to switch to "stand".  I need to complete the jump.  As soon as the avatar lands I release the boolean and the animation switches.  Works nicely.

Code: [Select]
public void moveForward(Object3D terrain) {
SimpleVector vnew = _main.getZAxis();

SimpleVector vcoll = _main.checkForCollisionEllipsoid(vnew, _ellipsoid, 5);

boolean bNoHit = (vcoll.x == vnew.x && vcoll.z == vnew.z && vcoll.y == vnew.y);

vnew = vcoll;
vnew.y = 0;
_main.translate(checkGroundDynamics(vnew, terrain));


private SimpleVector checkGroundDynamics(SimpleVector vnew, Object3D terrain){
SimpleVector vret = null;

SimpleVector vdist = new SimpleVector(0, 1, 0);

float fdist = terrain.calcMinDistance(_main.getTransformedCenter(), vdist);

if (fdist != Object3D.COLLISION_NONE) {
fdist -= 10;
vdist.scalarMul(fdist - 4);

float jump_offset = getJumpOffset();

float fdiff = (_height_offset + jump_offset) + vdist.y;

// end any jump if a surface was discovered - typically jumping
// to a higher plane will cause this....
if(fdiff == 0 && _blocking_animation)
_blocking_animation = false;

// simulate gravity and smooth the jarring movement upward as well.
// this may cause some minor clipping on slopes but its too jarring without it
// making jumps hard to control.
if(fdiff > SMOOTH_FACTOR_Y)

if(fdiff < (SMOOTH_FACTOR_Y * -1f))
fdiff = SMOOTH_FACTOR_Y * -1f;

vnew.y = fdiff;

vret = new SimpleVector(vnew);

}catch(Exception e){
System.err.println("CreatureComposite::checkGroundDynamics() " + e.getMessage());
return vret;

private float getJumpOffset(){
SimpleVector vret = null;
if(( || &&       _blocking_animation){
float fdelta = 0f;
if(_ai.frame < _ai.duration/2f){
_ai.jump_offset -= _ai.jump_rate;
_ai.jump_offset += _ai.jump_rate;

}catch(Exception e){
System.err.println("CreatureComposite::checkJumpDynamics() " + e.getMessage());
return _ai.jump_offset;

« Last Edit: May 10, 2007, 12:52:31 pm by ToddMcF2002 »