Collision Platform Problems

[Leeesaw]

Ok so I want the player to jump through the platforms and then land on top of the platform. I made my collision so that its only the top of the platforms, but when i turn "repeat while colliding" to YES... as soon as my player touches the platform (in the middle of jumping through) it auto puts the player on top of the platform.

Please Help.

[DST]

Here ya go.

collision>top side>platform>repeat yes

Code: Select all

if(yvelocity>0){
PhysicalResponse(MOVE_EVENT_ACTOR_ONLY, USE_CALCULATED_MASS, 1.000000, 1.000000, 000000, 1.000000);
canjump=1;
               }

therefore, it only happens if he's falling (or 'falsefalling' for the repeat collision+gravity that occurs when he's walking).

Assuming you are familiar with canjump? here's the draw actor from the test i performed before giving you advice...

Code: Select all

char *key=GetKeyState();
if(key[KEY_LEFT]==1){
    xvelocity=-5;}
else if(key[KEY_RIGHT]==1){
    xvelocity=5;}
if(key[KEY_RSHIFT]==1){
if(canjump==1){
yvelocity=-22;
canjump=0;
              }
                     }
yvelocity++;

[Leeesaw]

I am essentially using the same code in my game, but I did try out your code in a new scene and it has the same problem. My guess is: that if your player is halfway through a block when the velocity == 0 (essentially when gravity kicks in) then the player is placed on top of the block.

I attached a quick demo of the problem. The player shouldn't be able to reach the platforms...

[DilloDude]

I encountered this problem before. What I ended up doing was this:

Code: Select all

    double yv = yvelocity;
    if (yv > -1) // if we're not moving down, we shouldn't collide.
    {
        double ychange;
        PhysicalResponse(MOVE_EVENT_ACTOR_ONLY, USE_SPECIFIED_MASS, 1, 1, 1, 1); //apply the physics
 
        ychange  = abs(yprevious - y); //how much has our y position changed?
        if (ychange > yv) // if we've moved further than our initial yvelocity, we shouldn't have collided
        {
            yvelocity = yv; //reset our yvelocity
            y = yprevious + yvelocity; //reset our y position
        }
        else //otherwise, the collision was correct
        {
            oG = 1; //we adjust our onGround variable, and do any other actions we would do on the collision
        }
    }

[Leeesaw]

Sigh... still not working. I tried your code in various ways and its still having all sorts of issues.

Though I think its probably more to do with my own messy code... Ill play around a bit more.

[Leeesaw]

Here is what is going on now...

[DST]

I'd suggest changing the rate of jump for your character, or changing the levels of the platforms. The timing of your game is probably the most important factor.

in any game, no matter how professional, there are limits to the scripting. Almost all of the time, the gameplay itself is adjusted to meet the requirements of the engine.

Remember how older games make you invincible for a second when hit? Just imagine what would happen if they didn't, and you got stuck between an enemy and an enemy statue, bouncing back and forth, getting hurt until death? the invincibility was a method to overcome limitations of the engine.

Btw, i always wanted to tell the world SHINOBI on the NES sucked big because you could get bounced between two enemies until death. I hope the company that made that version of Shinobi feel bad. It was a terrible version of a great game.

[Leeesaw]

Thanks for all the help everyone

SO what I ended up doing:

I made an actor at the feet of the player (an almost completely transparent box) and named it feetCollision.

I set it so the feetCollision is parented to the player. If the feetCollision is colliding with the platform then oG=1;

and then if the player is colliding with the top of platform:

Code: Select all

if(yvelocity>0)
{
    if (oG ==1)
      {
          PhysicalResponse(MOVE_EVENT_ACTOR_ONLY, USE_CALCULATED_MASS, 1.000000, 1.000000, 000000, 1.000000);
           canjump=1;
        }
 }


This still leaves 2 problems.

If my player is standing on one platform... and their head (or any part of their body) touches another platform this will cause the player to jump up to the higher level.
To solve this im going to make my platforms a bit differently than I have. Instead of one giant platform actor im going to make a couple individual types of platforms (2 blocks across, 3 blocks across,etc) and then clone them. I think this will make the placement of platforms much much easier anyways.

The other problem is if my player is falling really quickly the feetCollision doesnt trigger and the player will pass through the platforms. Im not sure if there is a great way to fix this... for now im going to leave it and simply make sure that the ground actor isnt dependant on feetCollision.


Ok so that is how I hacked it together. Games are all smoke and mirrors anyways. If anyone has a better solution let me know.

[DST]

1. Cap the max yvelocity of your player. For example, player>drawActor>

if(yvelocity<10){
yvelocity++;}

2. on the collision detection, use maxvelocity +1 as your minimum.

For instance, you can ask your collision box to respond if it is within11 pixels of where player should be; or you have a collision box 11 pixels tall, or whatever. Mathematically plan it so that player cannot fall through platform at high velocity.