Map construction



It's been a while now since I've done any mapping using Hammer (or Worldcraft as it was back then), but I was wondering how the map geometry would be constructed in HL2 maps?

Would it be made from BSP or would something similar to the new Unreal editors be used (ie. static meshes created in another 3D modelling program)?
From the looks of the screenshots, it appears that the methods of creation are probably the same. Probably the hardest part in creating maps for HL2 after mapping for HL would be getting out of the habit of the style for HL to keep r_speeds down.
The file format for Hammer files is changed (not rmf anymore)
and alot of new features will be added.

Also the compiling tools are brandnew (offcourse)
yup, its now .vmf instead of.rmf and from what i hear we will be able to convert our old maps :dork:

also it has the ability for model preview like in the current hammer beta (3.5) but i think they will extend this in the new hl2 hammer.

there is more to the object propertys than before. ah i cant be bothered to list anymore, theres too much. if you want the screenshots then go here:

and if you want what seems to be rough guesses of what all the new features are then go here:

its the best one that you can find that details all the new features, with guesses of what they do
yup, its now .vmf instead of.rmf and from what i hear we will be able to convert our old maps

Where did you hear that?
This would be really good when modding, this way people can have maps layouts ready, as well as models and textures even before the SDK ships...
I read something about the SDK on, that valve planned on releasing the SDK even before the game, anyone that have heard of something that may confirm this?
Would be cool also, but I may have misread it :)
yea its supposedly out in august, and valve are thinking of doing a mod convention where they take a handfull of modders and invite them to there offices in america and show them the engine and let them get to grips with it for the day :cool:
AndersJ: Eric Johnston from Valve said in an I-view, i think it was on PHL, that the SDK will be released earlier then HL2 :) Cant wait, huh ? :D
The only thing I am worried about is that I go away for training in the summer! July 19th to August 14th I am on course, then on the 16th there is a huge field training exercise until the 26th I think. I want to be around as soon as the SDK is released :(
That would be awesome if you could convert your old HL maps. But it would suck for the people who planned on being able to do that, made a whole map and then couldnt convert it when HL2 comes out.
you cna map out whole leves in 3ds max now, but they wont have the interactivity that maps made with the engine will have. you'll also have to go back through it and put in all the physics info and stuff.
just wait for their official editor to be released so you won't have to add in all the physics stuff to your old maps.
There may be changing that would affect map construction. Since the physics engine folows the collision hulls of things exactly, you may be able to construct more realistic proportioned not requiring 2 and 1/2 foot wide doorways everywhere.
Well the topic was how is map geometry going to be constructed in Hammer for HL2.

BSP based geometry or seperately modelled in an outside 3d program such as XSI or MAX.
Well I think and hope that we get to make our objects seperate as well, models should play a big role I think.
I don't know but I like it that way, and I'm sure Valve will release their model-tool with hammer.
I believe I read something about it somewhere as well, and people often state that hammer is mor a mod-tool than a mappingprogram.
If that's the case it MUST have modelstuff in it.
But the map itself will prolly be designed as in original hammer, the screens suggests so anyway.
Isn't BSP based geometry quite memory hungry though?

With the new Unreal editors they use "static meshes" which are modelled in an outside 3D application. Each instance of an object which is visible on screen is only loaded into memory once, no matter how many of them are visible at one time. So if you had 50 barrels on screen then only 1 barrel is loaded into memory, quite a saving.
A few issues need correcting as poeple are getting confused and using terminology incorrectly. Hammer never has (and will probably continue to not) let people create/edit BSPs. The geometry format that Hammer uses is based on convex brushes. These brushes are compiled into a BSP tree. The BSP tree is only nessesary when the game starts drawing the map. The BSP tree contains all of the polygons used to draw the map (analagous to Unreals mesh) rather than a set of solid brushes. A BSP tree is not really more memory hungry than a mesh, as the same polygons are contained. The only extra storage needed is for the internal nodes (only leaf nodes contain polygons) which each represent a plane in 3D space (hence the name Binary Space Partition). There is a good into to BSP trees here:

There is a lot of info about BSP trees and how 3D engines work online, I suggest people read as much as possible, as 3D engines become more complicated mappers ought to be aware of what is it they are actually creating.
So a BSP tree is used no matter how the map is built, whether its with convex brushes or static meshes? That makes sense.

So if an object is created in a map using convex brushes and another exact same shape object is also created using the same shape convex brushes then will those polygons only be stored in memory once and reused for each occurance? Is that what happens with the static meshes also?

All very interesting stuff. :cool:
Yes. There is a tolerence (that you can define) for how close two polygons have to be before on eof them is removed. You can't really do that with a mesh, imagine a mesh as one continous surface.

Not all 3D engines use BSP trees but it is a very common approach to guid the algorithm that is drawing the world.