Forums / Games / Halo: The Master Chief Collection (Xbox)

Collision Detection in Halo: CEA

OP JustAlex1997

As many of you are likely aware, the environments and objects seen within the remastered visuals of Halo: Combat Evolved Anniversary don't always match up with the original models' collision detection. This leads to grenades bouncing off of what looks like nothing, wasted bullets when shooting around corners, and various other issues. The bizarre thing is that the collision detection with the classic visuals isn't always perfect, and there are rare areas (such on inside of the Truth and Reconciliation) where the environment has been altered for the remastered visuals to better fit the collision detection. Is there any reason why there'd be such an inconsistent job done in regards to collision detection?
Did I understand correctly that you were seeing some collision issue with the game's geometry in classic graphics? As far as I'm aware, the original game's geometry wasn't altered in any way. Did you experience the same thing on the 360 version of the game? This might be one of those minor lingering issues with MCC if you didn't.
tuhin94 wrote:
Did I understand correctly that you were seeing some collision issue with the game's geometry in classic graphics? As far as I'm aware, the original game's geometry wasn't altered in any way. Did you experience the same thing on the 360 version of the game? This might be one of those minor lingering issues with MCC if you didn't.
The geometry seen in Halo: Combat Evolved Anniversary's remastered visuals don't match its classic visuals (leading to rocks being taller, walls being shorter, etc..) The collision detection matches that of the classic visuals, so throwing a grenade over a boulder may cause it to bounce off of the air in the remastered visuals as it was taller in the classic visuals. On rare occasions, Bungie messed up with the collision detection in the original game, and Saber Interactive took some of those instances to alter the geometry to match it.

Examples of each:

On the mission Halo, at the very beginning, there's a sunken-in cliff in the remastered visuals that bulges out in the classic visuals. The collision detection treats it as if it's bulging out regardless of which version you're playing.

On the mission The Truth and Reconciliation, there's a flat wall in the classic visuals that has a hump in it in the remastered visuals. The collision detection treats it as if it has a hump regardless of which version you're playing.
I've never heard of collision detection being incorrect for the classic graphics and I'd think it'd be impossible just because of how the Blam engine works. If I'm not mistaken, the Halo level geometry is the level geometry and there is only one version of it. In modern games there are often multiple meshes (some render and some are just for calculations,) but Halo came out on the tail end of the 2nd gen of 3d games, and I tend to group it with Quake and Unreal, at least in terms of their engines. You may be mistaken because of minor differences between what's shown to you and what the game is calculating. Your weapon is not in the game world, it's a special model that is shown only on your hud. The weapon that you really have is the one your character model is holding, and it's muzzle may not be in exactly the same place as where you think it is. You mentioned corners, this is the most obvious spot this happens. There have been plenty of times where I'm trying to shoot a rocket around a corner. I can see the target, recital is red, and you pull the trigger only for the rocket to blow up on the wall next to you.

There was probably different levels of care paid to each mission just because designers get tired out, take shortcuts, or just plain miss things. For me, 15 minutes into any speedrun of The Library, my viewers always see me do this:

https://i.ibb.co/ZTwmMpz/oob.png

While it may look like it, I'm not out of bounds, I'm just tucked myself into a little corner where the new geometry goes so far over the original that you can walk through it. The Library is actually notorious for this as it's not the only place you can do this (it's just the only place that's useful in a speedrun.) There's actually an entire room right at the end of The Library that has a rocket launcher in it. There is a false wall over it so in anniversary, you wouldn't ever know it's there unless you happened to walk through the wall or know it's there from classic.
I've never heard of collision detection being incorrect for the classic graphics and I'd think it'd be impossible just because of how the Blam engine works. If I'm not mistaken, the Halo level geometry is the level geometry and there is only one version of it. In modern games there are often multiple meshes (some render and some are just for calculations,) but Halo came out on the tail end of the 2nd gen of 3d games, and I tend to group it with Quake and Unreal, at least in terms of their engines. You may be mistaken because of minor differences between what's shown to you and what the game is calculating. Your weapon is not in the game world, it's a special model that is shown only on your hud. The weapon that you really have is the one your character model is holding, and it's muzzle may not be in exactly the same place as where you think it is. You mentioned corners, this is the most obvious spot this happens. There have been plenty of times where I'm trying to shoot a rocket around a corner. I can see the target, recital is red, and you pull the trigger only for the rocket to blow up on the wall next to you.

There was probably different levels of care paid to each mission just because designers get tired out, take shortcuts, or just plain miss things. For me, 15 minutes into any speedrun of The Library, my viewers always see me do this:

While it may look like it, I'm not out of bounds, I'm just tucked myself into a little corner where the new geometry goes so far over the original that you can walk through it. The Library is actually notorious for this as it's not the only place you can do this (it's just the only place that's useful in a speedrun.) There's actually an entire room right at the end of The Library that has a rocket launcher in it. There is a false wall over it so in anniversary, you wouldn't ever know it's there unless you happened to walk through the wall or know it's there from classic.
You should probably read my response to tuhin94 as I point out specific examples of Saber Interactive's geometry not matching up with Bungie's. I'm not saying that they altered Bungie's geometry, but it is a fact that Bungie themselves made the occasional mistake.
Where is that wall in T&R? I read your post, and I assumed that you meant that Saber fixed some mesh issues, but it should be all or nothing. Unless I'm totally wrong, the game engine only has one mesh that it uses for everything so it's not possible for the classic graphics and classic physics to not line up correctly. If you throw a grenade at the wall, are you saying in classic graphics, it'll act like it hit something while it's clearly in the air? Or does it does bounce in a strange direction as though there was geometry that these isn't? That could actually be explained by an incorrect normal map. Normal maps are somewhat screwed up in the PC port anyway. Of course, I'd have to actually see where you're talking about.

I know where you're referring to in the Halo level, there's a bunch of places like that. Keyes is even worse with cliffsides.
Where is that wall in T&R? I read your post, and I assumed that you meant that Saber fixed some mesh issues, but it should be all or nothing. Unless I'm totally wrong, the game engine only has one mesh that it uses for everything so it's not possible for the classic graphics and classic physics to not line up correctly. If you throw a grenade at the wall, are you saying in classic graphics, it'll act like it hit something while it's clearly in the air? Or does it does bounce in a strange direction as though there was geometry that these isn't? That could actually be explained by an incorrect normal map. Normal maps are somewhat screwed up in the PC port anyway. Of course, I'd have to actually see where you're talking about.

I know where you're referring to in the Halo level, there's a bunch of places like that. Keyes is even worse with cliffsides.
You seem to be under the impression that I believe Saber Interactive altered the collision detection seen in the original Xbox version of Halo: Combat Evolved, but I'm not saying that at all. As far as I'm aware, the collision detection seen in Halo: Combat Evolved Anniversary is 100% identical to the original Xbox version of Halo: Combat Evolved. The problem is that the new models created by Saber/implemented into Halo: Combat Evolved Anniversary from other Halo games don't always match the proportions of the original models, so there'll be times where they made a boulder taller than Bungie did, so it creates an inaccurate perception of how much cover you really have as enemies can shoot through the parts of the boulder that are taller than the original Bungie model. On the flip side of things, there are times where Bungie themselves messed up, and Saber fixed some of their mistakes by making their new models to better match the collision detection. This shows an inconsistency in Saber's work.
First of all CE anniversary was not based on the xbox version, it was based on the PC release of Halo CE which was a piss poor port of the Xbox game. The next thing is that they did experiment with making the collision match with the new graphics. However it was eventually decided against leaving in only one place with updated collision in the level 343 guilty spark on the tree that you walk across. Otherwise collision matches the original graphics in all other places as far as I know. However MCC CE has been messed up even more. The spirit drop ships don't even fire from their turrets anymore, so it wouldn't surprise me if things got even more messed up as far as collision goes. I have mostly avoided CE ever since they messed up the drop ships. I made many complaints to the official forums about how messed up the CE campaign had gotten. I did it for like 5 months in a row and nothing was ever done about it.
First of all CE anniversary was not based on the xbox version, it was based on the PC release of Halo CE which was a piss poor port of the Xbox game. The next thing is that they did experiment with making the collision match with the new graphics. However it was eventually decided against leaving in only one place with updated collision in the level 343 guilty spark on the tree that you walk across. Otherwise collision matches the original graphics in all other places as far as I know. However MCC CE has been messed up even more. The spirit drop ships don't even fire from their turrets anymore, so it wouldn't surprise me if things got even more messed up as far as collision goes. I have mostly avoided CE ever since they messed up the drop ships. I made many complaints to the official forums about how messed up the CE campaign had gotten. I did it for like 5 months in a row and nothing was ever done about it.
I'm aware that Halo: Combat Evolved Anniversary was built off of the PC version of Halo: Combat Evolved, but I've seen nothing to suggest that the collision detection was altered by Gearbox when porting the game to PC. I'm also very much aware that Halo: The Master Chief Collection is a broken mess, but the issues I refer to are very much present in the Xbox 360 version of Halo: Combat Evolved Anniversary as well.

I'm not sure how much clearer I can say this, but I know that Saber Interactive didn't alter the collision detection of Halo: Combat Evolved when making Halo: Combat Evolved Anniversary. Why is it that multiple people think that I believe otherwise?
First of all CE anniversary was not based on the xbox version, it was based on the PC release of Halo CE which was a piss poor port of the Xbox game. The next thing is that they did experiment with making the collision match with the new graphics. However it was eventually decided against leaving in only one place with updated collision in the level 343 guilty spark on the tree that you walk across. Otherwise collision matches the original graphics in all other places as far as I know. However MCC CE has been messed up even more. The spirit drop ships don't even fire from their turrets anymore, so it wouldn't surprise me if things got even more messed up as far as collision goes. I have mostly avoided CE ever since they messed up the drop ships. I made many complaints to the official forums about how messed up the CE campaign had gotten. I did it for like 5 months in a row and nothing was ever done about it.
I'm aware that Halo: Combat Evolved Anniversary was built off of the PC version of Halo: Combat Evolved, but I've seen nothing to suggest that the collision detection was altered by Gearbox when porting the game to PC. I'm also very much aware that Halo: The Master Chief Collection is a broken mess, but the issues I refer to are very much present in the Xbox 360 version of Halo: Combat Evolved Anniversary as well.

I'm not sure how much clearer I can say this, but I know that Saber Interactive didn't alter the collision detection of Halo: Combat Evolved when making Halo: Combat Evolved Anniversary. Why is it that multiple people think that I believe otherwise?
They actually did alter it though. The tree in the level 343 is an obvious place. I don't know of any others. Hopefully 343 will update Halo CE and improve it, but I doubt it. Betting it gets worse once Reach is put in.
Is there any reason why there'd be such an inconsistent job done in regards to collision detection?
As far as the community is aware, no there is no reason. If I had to take a guess Saber got lazy and literally cut corners from the remastered visuals.
Yeah, I hate the turret in the wrong place bug. Completely screws. the regular speedrun strategy for the second level. However, that has nothing to do with collision detection, what likely happened there is a developer accidentally zero'd out what's called a "Transform" which gives a sub-object's relative position and angle. I'm guessing the point the turret now fires from is (0, 0, 0) relative to the origin of the ship.

Anyway, how did you come to the conclusion that the fallen tree's collision has been altered? While I still have my original game CD, I don't have an original XBox, so I can't do my own comparison. Then my second question is did the geometry of the tree change, or just the geometry of the collision? Because of the fact that geometry even way outside of the map is still solid, I assume that the exact same mesh is used for rendering and collision. Modern games have different meshes, but Halo's engine is relatively primitive, it doesn't even have LOD.

Where'd you hear about that tree? I couldn't find anything online. It's also no where near my regular path through that section of that level so I probably wouldn't notice anyway.
I'll never get two things:
1. Why did saber change the collision in the 360 release? Did they just want the remaster to feel unconvincing?
2. They could fix this in the MCC version, but they didn't. What I think is worse, they matched the colission of some models (like they should) but not with everything, therefore you can not ve sure which visuals give you the correct colission.
I'm still curious to see some comparisons. I'm a speedrunner, we're one of the groups of people who would be greatly effected by changes in collision detection on seemingly mundane features. Some of our tricks require us to jump off of very specific geometry or bounce a grenade in a very specific spot and all of these tricks work. I think someone in this thread mentioned the Covenant dropship. While they did screw up the turret location, the geometry seems unchanged to me. We do a jump on T&R that requires getting a grenade stuck in a crease at the tail of the phantom, and that still works. Rocks in AOTCR are also very important because which rock spawns is random and we have to check which ones we get when jumping down from the bridge, some rocks collision will kill you and some will let you get down, that all still works as far as I can tell. Of course, we're usually way off of the normal path so maybe only on more trodden paths they decide to fix stuff that doesn't affect me during casual play?