Invisible Platform Clipping

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Scuba Steve
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Joined: Sat Mar 27, 2004 8:56 pm

Invisible Platform Clipping

Post by Scuba Steve »

Was something changed regarding the behaviour of invisible bridge objects? This didn't use to be the case, but now if there happen to be invisible objects above me and I walk up stairs into them I can get stuck in their clipping bounds.. unlike previously where I was not allowed to walk higher if I was in their radius.

Does that make any sense?
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Graf Zahl
Lead GZDoom+Raze Developer
Lead GZDoom+Raze Developer
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Post by Graf Zahl »

Yes, something was changed. Previously when looking for a bridge thing to stand on the engine just selected the first one it found, regardless of height. But it should select the highest one the player can stand on. Maybe something is wrong with that code. Do you have a test map?
Scuba Steve
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Joined: Sat Mar 27, 2004 8:56 pm

Post by Scuba Steve »

http://action.mancubus.net/files/stairtest.wad

You'll have to fly up to the middle segment to test it. Try walking up right side of the steps and it works fine, but if you walk up on the left, you'll get stuck in the top objects bounding box.
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Graf Zahl
Lead GZDoom+Raze Developer
Lead GZDoom+Raze Developer
Posts: 49235
Joined: Sat Jul 19, 2003 10:19 am
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Post by Graf Zahl »

Ugh...

Another messy result of the shitty movement clipping that is close to unfixable. Doom's movement code contains 2 serious design flaws that again work perfectly well together to create an uncontrollable situation. (Flaw one is to separate horizontal from vertical movement, flaw 2 is to make the basic movement check 2-dimensional.)

The bug is caused by the stepping on things check being done in the vertical movement code so when it is detected that the move is illegal it should reset the already performed horizontal movement as well. But thanks to the bad design that is not as easy as it sounds.

BTW, with the old incorrect code this didn't work properly as well because the player didn't even step on the bridge things and therefore couldn't get stuck.

The only recommendation I can give is not to stack bridges so tightly that you can get stuck just by walking on them. Always allow enough vertical space at each position that the player has enough room to stand free.
Scuba Steve
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Joined: Sat Mar 27, 2004 8:56 pm

Post by Scuba Steve »

The way it used to work, you couldn't get stuck... but you wouldn't "climb" the steps... you'd have to press jump to reach each new step.
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Graf Zahl
Lead GZDoom+Raze Developer
Lead GZDoom+Raze Developer
Posts: 49235
Joined: Sat Jul 19, 2003 10:19 am
Location: Germany

Post by Graf Zahl »

You couldn't step up due to a bug I fixed. If you had ordered the bridges differently you would have gotten stuck the same.
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