Radial Gravity
Battle-Bug
Join Date: 2010-02-11 Member: 70523Members
Join Date: 2010-02-11 Member: 70523Members
<div class="IPBDescription">Why is gravity always uniformly down?</div><!--coloro:#00BFFF--><span style="color:#00BFFF"><!--/coloro--><b>Introduction:</b><!--colorc--></span><!--/colorc-->
Gravity is one of the fundamentals of physics in video games. Most games out there restrict gravity to being planar. That means that it always pulls you straight down in the same direction no matter where you are. However, an exciting alternative would be radial gravity. Imagine you have a space outpost built around a high density asteroid or imagine you have a spinning space station and the centrifugal forces bring you to the outside of the structure. This would make for some seriously different looking levels and gameplay.
<!--coloro:#00BFFF--><span style="color:#00BFFF"><!--/coloro--><b>Suggestion:</b><!--colorc--></span><!--/colorc-->
Create an option for centrifugal gravity. There would be a point or axis that the gravity points to or away from (cylindrical or spherical shaped gravity). It could be at a gradient (weakest or strongest at the middle) or it could be constant. The gradient would allow for some cool zero gravity battles at the center of a centrifugal space station (note: this is not a zero gravity thread). Constant would still make for some interesting gameplay.
<!--coloro:#00BFFF--><span style="color:#00BFFF"><!--/coloro--><b>Result:</b><!--colorc--></span><!--/colorc-->
- New level geometry
- New strategy opportunities
If any of you map makers want to take a crack at this to simulate what it would look like, it would really enhance this thread :)
<!--coloro:#00BFFF--><span style="color:#00BFFF"><!--/coloro--><b>Disadvantages:</b><!--colorc--></span><!--/colorc-->
It would be difficult to have commander view with a round level. This might be best for non-commander game modes.
This has the possibility of giving aliens a slight advantage in that the curvature may allow them to hide up a curved hallway where marines with long range weapons can't see them. However, there aren't many long hallways in NS anyways, so it shouldn't be a problem.
Planar (Normal) Gravity:
<img src="http://img528.imageshack.us/img528/4458/planargravity.jpg" border="0" class="linked-image" />
Centrifugal gravity space station with gravity around an axis:
<img src="http://img718.imageshack.us/img718/4907/centrifugalgravity.jpg" border="0" class="linked-image" />
<img src="http://www.lakesidepress.com/fictitious-reviews/spacestation5.jpg" border="0" class="linked-image" />
Imagine hallways with a slight curve to them:
<img src="http://3.bp.blogspot.com/_1T9YXyM1Bfw/SGPgJnefb1I/AAAAAAAAANA/WRfhXoNFuQc/s400/2001SpaceOdyssey025.jpg" border="0" class="linked-image" />
Imagine a marine near the center of the space station. The room is very curved:
<img src="http://img690.imageshack.us/img690/1197/2001spaceodyssey20.jpg" border="0" class="linked-image" />
Another view of the same room:
<img src="http://www.coudal.com/i/kubrickonset.jpg" border="0" class="linked-image" />
High density asteroid with radial gravity to a point:
<img src="http://img168.imageshack.us/img168/6044/radialgravity.jpg" border="0" class="linked-image" />
Most of these pictures are from 2001: A Space Odyssey
<!--coloro:#FFFF00--><span style="color:#FFFF00"><!--/coloro--><b>Note: Please keep all posts objective and constructive. It is ok not to like this suggestion, but it is not ok to be outright rude. If you don't like this suggestion, then please explain what it is exactly you don't like. It is very much appreciated if you provide alternatives to make this idea acceptable.</b><!--colorc--></span><!--/colorc-->
Gravity is one of the fundamentals of physics in video games. Most games out there restrict gravity to being planar. That means that it always pulls you straight down in the same direction no matter where you are. However, an exciting alternative would be radial gravity. Imagine you have a space outpost built around a high density asteroid or imagine you have a spinning space station and the centrifugal forces bring you to the outside of the structure. This would make for some seriously different looking levels and gameplay.
<!--coloro:#00BFFF--><span style="color:#00BFFF"><!--/coloro--><b>Suggestion:</b><!--colorc--></span><!--/colorc-->
Create an option for centrifugal gravity. There would be a point or axis that the gravity points to or away from (cylindrical or spherical shaped gravity). It could be at a gradient (weakest or strongest at the middle) or it could be constant. The gradient would allow for some cool zero gravity battles at the center of a centrifugal space station (note: this is not a zero gravity thread). Constant would still make for some interesting gameplay.
<!--coloro:#00BFFF--><span style="color:#00BFFF"><!--/coloro--><b>Result:</b><!--colorc--></span><!--/colorc-->
- New level geometry
- New strategy opportunities
If any of you map makers want to take a crack at this to simulate what it would look like, it would really enhance this thread :)
<!--coloro:#00BFFF--><span style="color:#00BFFF"><!--/coloro--><b>Disadvantages:</b><!--colorc--></span><!--/colorc-->
It would be difficult to have commander view with a round level. This might be best for non-commander game modes.
This has the possibility of giving aliens a slight advantage in that the curvature may allow them to hide up a curved hallway where marines with long range weapons can't see them. However, there aren't many long hallways in NS anyways, so it shouldn't be a problem.
Planar (Normal) Gravity:
<img src="http://img528.imageshack.us/img528/4458/planargravity.jpg" border="0" class="linked-image" />
Centrifugal gravity space station with gravity around an axis:
<img src="http://img718.imageshack.us/img718/4907/centrifugalgravity.jpg" border="0" class="linked-image" />
<img src="http://www.lakesidepress.com/fictitious-reviews/spacestation5.jpg" border="0" class="linked-image" />
Imagine hallways with a slight curve to them:
<img src="http://3.bp.blogspot.com/_1T9YXyM1Bfw/SGPgJnefb1I/AAAAAAAAANA/WRfhXoNFuQc/s400/2001SpaceOdyssey025.jpg" border="0" class="linked-image" />
Imagine a marine near the center of the space station. The room is very curved:
<img src="http://img690.imageshack.us/img690/1197/2001spaceodyssey20.jpg" border="0" class="linked-image" />
Another view of the same room:
<img src="http://www.coudal.com/i/kubrickonset.jpg" border="0" class="linked-image" />
High density asteroid with radial gravity to a point:
<img src="http://img168.imageshack.us/img168/6044/radialgravity.jpg" border="0" class="linked-image" />
Most of these pictures are from 2001: A Space Odyssey
<!--coloro:#FFFF00--><span style="color:#FFFF00"><!--/coloro--><b>Note: Please keep all posts objective and constructive. It is ok not to like this suggestion, but it is not ok to be outright rude. If you don't like this suggestion, then please explain what it is exactly you don't like. It is very much appreciated if you provide alternatives to make this idea acceptable.</b><!--colorc--></span><!--/colorc-->
Comments
It isn't bad as a gimmick for a slow paced exploration game, but for a fast paced arcade shooter it just gets in the way.
Not to mention mapping on curves is really hard, it would invalidate all the existing art assets because they're all built around a grid design and curves always incur high polycounts, not to mention it's hard to align things to curves whereas a grid can be used to make seamless maps quite easily.
I completely agree. The map connects back with itself on one end. So when you have two ways to the enemy base, instead of going left or right, you might go clockwise or counter-clockwise.
If it is implemented on smaller maps, it would really bring out the skill of jetpackers, lerks, and other fliers because the direction of gravity would be constantly changing. Lets face it, it doesn't take a whole lot of skill to fly around anyways. A <b>slightly </b>higher degree of difficulty might reward those with skill.
As far as fun goes, this would add a new element to the game and provide more variety. It would be less of the same thing over and over because there will be many new possibilities. It would also change the way you think about a level, changing strategy.
Imagine, if you will, a flat map. Now curve it around into a circle. When you think about the location of the hive, you don't see it as in front of you, 300m off. You think of it as above you, 100m. It changes your whole perspective.
Would it be easy to create gravity fields? So we make a box and the gravity in the box points a certain direction. If so, we could create "slices of the pie" and piece them together. With enough slices, it could seem fluid.
How do you design the level around it? How do you curve tiles designed for grid arrangement? A circle is made of trapeziums whereas all the current art assets are squares.
How do you work on a circular grid? or a spherical grid?
No it is not easy, not remotely.
It turns the entire game into an endless repeating plane, rather than the square arrangement which has edges, an edge gives you security at one or more sides, if the level just loops around you don't get edge rooms, every room connects in all directions, unless you just don't use the repeating system in which case why bother implementing it?
But let me guess an answer from my limited experience: Yes, it'd be easy given enough time.
So it returns to puzl's question, really. If someone's implementing it, it needs sufficient motivation in the "fun" department.
The commander view would probably make it difficult to do, but not impossible. I can imagine the commander seeing a flattened-out view of the map (sort of like when you see a flat world map). It could optionally let the commander scroll infinitely in the (counter-)clockwise direction.
The commander view would probably make it difficult to do, but not impossible. I can imagine the commander seeing a flattened-out view of the map (sort of like when you see a flat world map). It could optionally let the commander scroll infinitely in the (counter-)clockwise direction.<!--QuoteEnd--></div><!--QuoteEEnd-->
A flat world map isn't accurate though, it's heavily distorted, if you tried that with something the size of a game level it would warp everything, you're basically suggesting taking the entire world and flattening it out but keeping the 3d aspect during runtime, it'd be horribly complicated to code and would lag unbelievably, especially when you take into account all the shaders and things which are designed to run in a normal 3d representation of the world.
To flatten something like that you'd basically have to bend the entire game space so that it flattens out, I can't even begin to fathom the number of problems with that, or how you would adapt it to all the possible map configurations.
It was cool when <i>Prey</i> did it, but that was a game built around that concept. NS isn't, which will make it much harder to incorporate effectively late in production.
To have surface gravity comparable to that of earth, an asteroid of that size would need extraordinarily high <a href="http://www.google.com/search?q=9.8m%2Fs^2%2F%28G*4%2F3*pi*%28150m%29%29" target="_blank">density</a> - about 10^5 the density of a typical asteroid and nearly that of a white dwarf (electron degenerate matter).
To have surface gravity comparable to that of earth, an asteroid of that size would need extraordinarily high <a href="http://www.google.com/search?q=9.8m%2Fs^2%2F%28G*4%2F3*pi*%28150m%29%29" target="_blank">density</a> - about 10^5 the density of a typical asteroid and nearly that of a white dwarf (electron degenerate matter).<!--QuoteEnd--></div><!--QuoteEEnd-->
I figured someone would say something like this. From what I can tell, most forum goers aren't in favor of that much realism :)
I mentioned that comm view would be difficult for a reason. I don't see it as reasonable to code the comm view. It would work, however, if the comm could rotate the whole map around instead of just a bird's eye view. Though, I believe we should just leave this idea for non-comm game modes.
But yeah the engine would need a serious overhaul to support this. And NS style doesn't seem to fit the wild and weird kind of game play like of Prey... its more blocky and orderly.
I don't think that there'd be enough gravity to notice an arc in bullets (I don't believe they are even coded to respond to gravity). There also wouldn't be a long enough distance. I'm prefer not to describe the physics.
I would like to see some custom gravity setups available in NS2...
nuff said.
I support you with the laws of physics but this makes the game too complicated for devs and easier solutions are found.
nuff said.
I support you with the laws of physics but this makes the game too complicated for devs and easier solutions are found.<!--QuoteEnd--></div><!--QuoteEEnd-->
... That just lowers it / turns it off.
Does not allow for the centrifugal effect of a spinning space station for example.
Maps can't be too curved or it'd just be like fighting a continuous uphill, or downhill battle. If you make the maps big enough, and the curve gentle enough, it really isn't that much different from a map which doesn't allow you a long line of sight.
The only interesting thing that can come out of it, is where in a donut shaped space station, with the centrifugal force working outwards away from the centre, is that if one player can look up, and see another player on the other side of the ring. That might result in interesting strategies.
you can search for it if you feel lucky.
The problem is that you don't want to see the enemy base 100m above you. Long range attacks ruin that.
The purpose of radial gravity and curved maps is to skew your mind. You are thinking 3D instead of 2D. Try to imagine navigating a map when you know that your objective is above you and there is not a direct path.
But let me guess an answer from my limited experience: Yes, it'd be easy given enough time.
So it returns to puzl's question, really. If someone's implementing it, it needs sufficient motivation in the "fun" department.<!--QuoteEnd--></div><!--QuoteEEnd-->
Oh gawds transforming into cylindrical/spherical coordinates.
The biggest issue I forsee are 2 things.
1) Need a new coordinate system to perform this correctly. Hacking it with disjointed gravity boxes will simply make the mapper's life hellish and cause serious issues as you move between the regions. Basically, we'd need to redsign the physics and such to work in r-theta-z coordinates for a torus instead of the x-y-z coordinates we use now. Spherical is yet another set of coordinates. As mentioned, it's not impossible and has an elegant solution, but it's a foundational fix and thus changes EVERYTHING. And that takes time. Plus, if you want to simulate rotational gravity, you need to also have less gravity towards the axis. That's more of an extra unnecessary perk, but something to keep in mind. People will ask "Hey, we have rotational/radial gravity, so why doesn't it let up the closer we go to the center?"
2) Scale. This only works for large scale. And that scale is in one dimension. Too small of a radius would create too sharp of a curvature and thus changing gravity direction too quickly, disorienting players. See Celestial Impact and the problems when you bore a hole through the asteroid. The next issue is that we've scaled in one dimension, so we need a similar scaling in the other dimension or else it becomes linear push map in 2 directions. This means HUGE maps. And we've also broken the paradigm of roughly equidistance between the 4 major tech points, unless we can ensure that the two team start on opposite ends of the torus. Even then, opposite tech points are still extra far, limiting strategic deployment. Unless we carve central corridors. But then see the proportional gravity issue above. Similar issues with a sphere.
So, here's the solutions.
1) don't do it. It just makes life easier. yay approximations of a pseudo flat world.
2) Only in minute amounts. i.e. slight curvature to the map. And just handwave that the rest is outside the map. This helps mitigate the issues of making a giant torus/sphere (scale, not equidistance), but at the same time we lose all the neat features of a torus/sphere.
Also, as people have already mentioned, comm view become a nightmare. Sure you could say limit them to only looking down from the ceiling as the run around the inner edge of the torus or the outer edge of a sphere, BUT then we can't use those central corridors to connect two opposite side through the center.
I should also note that I think Shattered Horizons mitigates this by making everything ZeroG, and it's all relative to the player's orientation what they consider up or down. Thus, it's less disorienting. However, for radial gravity, you have to obey whatever the maps says is up and down and changing that too quickly hurts. Someone correct me if I'm wrong there because I haven't actually played Shattered Horizons.
Additionally, the strength of "gravity" should depend on your velocity relative to the nearby ground. If players can move anywhere near as fast as in NS1 (and the radius is small enough that a playable map can span the circumference) this would be a very significant effect.
How about we not do that and just place the point or axis of gravity and specify the strength of that gravity? That way, we can just make a map and place the gravity center where we want. So, it'd be no different than placing a light source, only it's gravity. Those making round maps will just have to eyeball the shape. Spark might get a few tools to help in the process of round maps (if wanted). However, I don't believe it is necessary to create a whole new coordinate system. We make tons of objects that are non-planar in spark and modeling programs.
<!--quoteo(post=1755499:date=Feb 26 2010, 02:44 PM:name=a_civilian)--><div class='quotetop'>QUOTE (a_civilian @ Feb 26 2010, 02:44 PM) <a href="index.php?act=findpost&pid=1755499"><{POST_SNAPBACK}></a></div><div class='quotemain'><!--quotec-->Additionally, the strength of "gravity" should depend on your velocity relative to the nearby ground. If players can move anywhere near as fast as in NS1 (and the radius is small enough that a playable map can span the circumference) this would be a very significant effect.<!--QuoteEnd--></div><!--QuoteEEnd-->
This is going a bit too far towards realism. That's also a bunch of code. We're talking a stationary map with differently shaped gravity. No reason to make it much more complex than that.
Because calculating gravity that is radial in nature in a xyz coordinate system sucks? Or, rather, is extremely inefficient?
As an added bonus, orientation calculations become much more painful. Especially as objects interact with each other.
no I actually like this idea :) but it could make commanding quite hard as it needs a top view of things
As an added bonus, orientation calculations become much more painful. Especially as objects interact with each other.<!--QuoteEnd--></div><!--QuoteEEnd-->
Not to mention mapping on an XYZ grid for a radial map.
Really, really, horrible, the entire grid snap goes out the window and you have micro-cracks everywhere because props don't fit exactly and aaargh horrible.
Mapping on a radial coordinate set would actually be easier I think even if it is a complete mind-screw.
gravity traps and stuff wouldn't bee too hard, its just a really strong trigger push and them sticking to the ceiling (sculk wall crawl)
i like the thought of falling up and ambushing the ppl on the ceiling
all this is possible between hl1 and ns1
So perhaps "low gravity" maps? Would be.... unique.
Localized changes in gravity, a la a zero-G room or an invertedG "test" room might also be OK, but you'd have to be very careful about how you deal with it. The best I've played is the Dead Space implementation and the Dystopia Cyberworld does a good job, but I've heard good things about Prey and Shattered Horizon.