physics definition - personal observations

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Zardoz
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physics definition - personal observations

Post by Zardoz »

So beta 4 is on the verge of being released you say eh? Good, good.

I know it's late in the game to ask for feature requests but I just crawled home from work, I'm bored and nobody else feels like posting anything bloody. So here goes.

I loaded up shar wre blood 1.11 (I know, wrong version) Just to see if I could squeeze some physics out of this sucker that might help TF become more bloody. All apologies for those of you who know this stuff and are tired of hearing about it.

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First off, velocity factor when playing kick the head.

At walking speed a kicked head will travel 1- 2 seconds. It may simply slide across the ground or it may spin a little, but it won't travel for more than 2 seconds.
At running speeds a kicked head will always travel at least 2 seconds and may go for 4 (5?).

Distance traveled when playing kick the head also effects these scores. If player stands back at a fair distance and gets a good kick at running speed , player will achieve maximum head velocity, hight and bouncing.

Player may start a running kick at closer distances, but somehow build detects this and doesnt reward player with maximum head travel. The key is length of time holding velocity- not just speed.
Same goes for a walking kick.

kicked bucket acts similarly.


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Angle of attack when stabing or shooting.

The observations that follow were gathered while playing the first half of wrong side of the tracks over a period of several hours. All attempts to replicate of disprove observational data are appreciated.

The above experiment can be replicated by doing the following. Jump up on the ledge at the beginning of the level where the train cars with the tnt barrels blocks the path of player. Acktivate the 2 zombies in the court yard, stay on the ledge wich is fairly safe. With the pitchfork stab downwards - niotice if Zombies are knocked back more than if player was level with them. Now try the same thing while stabing upwards. Go the the second car (the one that rotates to reveal a door) and wake up the zombies within. Stab upwards
and see if they aren't knocked back more (and up into the air!) than if at same level with player (you'll be all right as long as they don't jump down).

I've noticed they fly upwards and back more if struck at extreme angles.
try the same experiment with the shotty for a more dramatic example.

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Gibbing

Some of the destroyed monster gibs maintain a hit scan after being killed that responds to physics. The headless torso zoombie gib can be stabed at least one more time after spawning and after it has dropped a kickable head- this usually results in the torso flying backwards a few feet. The torso will continue to spray blood a good five seconds after it comes to rest.
The universal flamin' dude who spawns after a live human has been set a blaze (it burns! it burns!) also response to physics in a similar manner.

gibs that spawn more gibs automatically without help from the player....

No I'm not drunk. I'll add to this later after some sleep.

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Jumping

I hope the q3map format get TF a little more control over physics.
When qblood was started all they could do for jumping is lower the gravity and that seems to be where tranfusion still is. Player's jump in blood lasts all of 1 second give or take. The ballistic arc seems very sharply curved downward. Transfusion players jump seems to last about 1.3 seconds give or take; Ballistic arc is rather shallow. Dispite the longer jump some jumps are harder to make in transfusion. The jump from the bench up and over to the left upper hallway as you enter the morningside mortuary for example.

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the joy of bounciness

It's 25% real and 75% illusion. Here's what I mean. If you hit scroll lock to holster weapon and start jumping around you'll notice a lot less of it. "There is a bending of the knees" when player re-contacts the ground, but if you watch closely while jumping with a weapon present you'll noticed it's mostly the v weapons view that has the most dramatic movement. When player first jumps, the v-weapon veiw drops dramatically, as player hits ground v- weap comes back up at a reduced speed.

Now, off to examine what happens when view bobbing is turned back on...

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Okay, time to start blathering again.

Yes I’m aware that all of the features below are known quantities and are planned for, I just need to vent about them.

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decals/ stain maps

Right now transfusion is using vanilla darkplaces stains for impact decals. Wouldn’t blood’s look better? they have a little more detail such as the cracks around the edges and they appear to be bigger.

Is it me or is darkplaces a little shy when it comes to allocating resources for stain maps? They start disappearing almost instantly once spawned. that might be understandable in multiplayer but can’t sp be a little more generous?

Also, does anyone else think stain decals are a viable option for replacing shell casing models? there are so few spawned that it looks like the players “rain of death” lasted about 3 shots.

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I consider this an open posting So I'll expand and make corrections (lots of 'em) on this diatribe as the days go on..
Last edited by Zardoz on Tue Aug 22, 2006 11:37 pm, edited 3 times in total.
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Willis

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Post by Willis »

Most of these are the little details that will be done in touch-up stages. Some of it is easy to do, some is harder, but we need to get the basics down first. I'm not saying they won't be done, they just won't be done before more important things.

Jumping will be tweaked shortly after the release of beta4 when we can see/feel how q3bsp is going to behave. It's not just the jumping that is a little off, but the entire movement honestly.

I've edited your title slightly, since Elric is no longer in the game code department.
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Post by scar3crow »

Is it me or is darkplaces a little shy when it comes to allocating resources for stain maps? They start disappearing almost instantly once spawned. that might be understandable in multiplayer but can’t sp be a little more generous?
I think Darkplaces is plenty generous with stainmaps, just from personal experience.

I myself like more subtle stainmaps with a decal system. Decals can fade away but powerful impacts can leave a stainmap... so long after corpses may be gone and decals have faded due to ram requirements, there is still evidence of a battle courtesy of stainmaps (since theyre good at scorch marks, brush marks, and blood saturation which you could argue occurs from gibbing).

Regarding physics... something is planned with Darkplaces in the future that LordHavoc is doing specifically for the standalone projects including Transfusion, Nexuiz and Darsana. He has a lot of changes planned just to ease their world - it is up to the individual teams if they will make the switch and if so what aspects they will utilize. I dont know if Im at liberty to discuss such in general, but I dont know the views of the Transfusion team of this either, Ive merely been around when LordHavoc was discussing this with other engine people and others in the Quake community such as FrikaC. Just saying, things are not stagnant.
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Zardoz
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Post by Zardoz »

scar3crow:
I myself like more subtle stainmaps with a decal system. Decals can fade away but powerful impacts can leave a stainmap... so long after corpses may be gone and decals have faded due to ram requirements, there is still evidence of a battle courtesy of stainmaps (since theyre good at scorch marks, brush marks, and blood saturation which you could argue occurs from gibbing).

Well... that shows you where I'm at. I thought decals and stain maps were the same thing. :oops:

Has anyone ever pulled apart blood to figure out the "how"of blood's physics? I mean there were times while playing blood in which you could get the distinct feeling that an entity being blown half way across a map had something to do with moving water. You could almost swear that, upon a strong enough blast such as that from a tnt barrel, blood was running the echo filter as said entity became airborne and was wisked away screaming, usually laterally to the players view.

If moving water is a sector effect, and any explosion with a high enough score triggers entity flight, then is it possible blood is adding and then subtracting sectors dynamically for highly responsive physics?

I know this is nothing but ignorant guess work on my part. But what else explains the echo filter running during heavy explosions?

Blood alpha has only one dynamic, fully rsponsive physical phenomenon that does not depend on gravity. It's that little vase that slides around when struck or shot. That little vase and its movement might contain all the seed code for later, more elaborate displays of an object contacting and transfering force/momentum to a second object.



Can the same be done with vertice based geometry?
Could Darkplaces add an invisable, 0 hit scan quake wind tunnel
that would appear latterally to the players view and intersect the explosion and entity, sendiing entity flying sideways and slightly upward?
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Zardoz
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Post by Zardoz »

There he goes....

There Zardoz goes again da da daaa....

scar3crow:
Regarding physics... something is planned with Darkplaces in the future that LordHavoc is doing specifically for the standalone projects including Transfusion, Nexuiz and Darsana. He has a lot of changes planned just to ease their world -
There was a time in the long forgotten past when talking about a new colision system could get the usually calm and affiable Lord Havoc into an angry and ugly mood.

Be that as it may, It would be wise to assume the worst whilst hoping for the best, eh?

Most 1st and second generation engines didn't take kindly to objects with balistic trajectories spinning. Blood 2's kick the head was an undramatic, slow motion affair. Same goes for transfusion's melon soccer. Now quake had a fairly bouncy pipe bomb, so as long as the object doesn't spin or require a large number of triangles to be redrawn, darkplaces can get head kicking back to its old bloody self again. Maybe if the 3d head was replaced by a colision box with enough ai to always have one face towards the player in flight.? Then you could have 2d animation running on one side of said box. Then again, maybe that has nothing to do with it and I'm up in my tree yet again.
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Post by predator »

Zardoz wrote: Could Darkplaces add an invisable, 0 hit scan quake wind tunnel
that would appear latterally to the players view and intersect the explosion and entity, sendiing entity flying sideways and slightly upward?
Effect like that can be achieved, even with q1bsp, and with q3bsp as well.
If you take a look at the airfist weapon in the Painkeep mod (Q), or Painkeep Arena mod (Q3), it's more or less what we need.
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