Brainstorming: Hammer Plugins

[Shrinker]

I can only say from experience that on a brush ent I had, with "higher" than one unit vertex precision, I was presented with a precision of one unit. But hell, that doesn't matter for me anyway, as I can manage these things in my editor. If you guys can compile them to be represented accurately enough in the bsps, then that's fine :P

[Mr. Happy]

Wait, are you making Hammer plugins somehow in addition to microbrush, or is this all about microbrush?

vbsp doesnt snap to grid at all. Brushes are saved as a collection of planes, using a standard floating point precision, and using some outerworldly algoritm these planes are transformed into a collection of points. Only points < 0.01 (or some other arbitrary number, Valve calles it EPSYLON iirc) away from the nearest gridpoint are rounded (as in, moved towards the nearest whole number coordinate). Don't believe me? The sourcecode for vbsp is given, so you can look it up; you will be searching for clipwinding* functions.
Hammer may round some vectors, i dont know as i dont have its sourcecode (except a very old hammer), but i cant imagine Hammer rounding vectors at random, possibly corrupting every non-cubic brush in the map, for no reason whatsoever (points on grid are in no way rendered or handled faster than points off grid).

I'm curious what happens when you accidentally do something like this: Create a square in top view. Move top left point slightly off grid. Drag top right point to top left, it does not ask you to merge vertices. Reopening map the 'collapsed' face is still in there, the vertices can be dragged away, but compiling there are no errors. What does vbsp do?

[Shrinker]

Wait, are you making Hammer plugins somehow in addition to microbrush, or is this all about microbrush?

Well I had a look around what people would have liked to have for Hammer to get the inspiration for Microbrush!

[...] What does vbsp do?

It silently deletes your adult picture collection, one bit each time :P

[Mr. Happy]

So that's where it's going!

Honestly, what microbrush needs is texture and displacement tools


But still, about vbsp,
I am really curious what it does for faces that occur between edges that it rounds in

[zombie@computer]

So that's where it's going!

Honestly, what microbrush needs is texture and displacement tools


But still, about vbsp,
I am really curious what it does for faces that occur between edges that it rounds in

vbsp doesnt round between faces, only in faces. err, lemme explain how vbsp construct brushes.

1) read brush (bunch of planes: unbound, flat sheet of space)

Each brushside has a plane, ergo a normal cube has six.

2) consider the nth plane (e.g. Top)
3) Create a brushside of infinite size (some arbitrary size like 64k*64k): this basically is a list of four cornerpoints:
(-64k, 64k, a) (64k, 64k, b) (64k, -64k, c) (-64k, -64k, d) : where a-d are Z values that move the cornerpoint to somewhere ON said plane.
4) For each other plane in this brush
Using lotsa mumbojumbo (im terrible at vector maths so its mumbojumbo to me, it incorporates lotsa dotproducts and normals and such), calculate intersection points and substract from the brushside. (If we were considering our Top plane, all other planes except the Bottom plane will substract one side of this 'infinite' brushside). If our Top side was at z=10, and we were considering our Front brushside at (y = -10) our Top brushside could look like this:
(-64k, 64k, 10) (64k, 64k, 10) (64k, -10, 10) (-64k, -10, 10).
after considering the Left brushside (at x=-20):
(-20, 64k, 10) (64k, 64k, 10) (64k, -10, 10) (-20, -10, 10).
etc.

I'm sure you can imagine slanted faces intersecting this plane could increase the number of vectors/cornerpoints, making these maths so difficult. You may even be surprised at how inaccurate the calculations are. One would expect a perfectly square grid-aligned brush will generate perfectly rounded cornerpoints, this is not the case! Rounding errors up 0.01 will occur even then!

5) Our brushface is nearly done! It should have nearly our finalised shape. So now iterate all vertices in our brushside and round them to the nearest whole point if they are less than 0.01 unit away from a whole point.
6) Remove duplicate points. After the Front and Left plane intersected and substracted from our infinite plane, rounding errors (usually caused by the limited precision of the floating point datatype), and/or after rounding them, we may be left with two vectors at the exact same place. This is unwanted, so remove these
If our brushside has zero points left (ie after all other planes substracted from it there is no plane left) remove plane.
9) if any of the infinite points remain, throw an error (e.g. brush coordinates outside map!)
10) Go to next plane (goto 4)

As you can see, brushsides are built up seperately. Rounding or even removing vertices only has effect on said brushface.

Whatever would happen in your case might be conducted from the above 'algorithm', i havent tried.

[Shrinker]

Honestly, what microbrush needs is texture and displacement tools ;)

Yes, yes. But first things first: Total programmability right out of the box!

About the brush algorithm stuff: I think I may have to look into a way of allowing the user to modify the vectors that define my planes. In Mb2 there was no way to do that and there was also no tool to "clean" that up. But it's really just intersections of half-spaces defined by one point on the plane and two spanning vectors each for being precise enough. Blahblahgoodnightfortonight :P

[Mr. Happy]

Wow thanks so much for that explanation zombie, I've read it a few times and I think I understanding whats going on.
That's more complicated than I'd imagined, I would have thought step three was unncessary since hammer also stores planes but I see that's in a different format. It seems like vbsp building the brushface at such a huge side would make the angled face intersections more accurate than the way Hammer constructs brushes on load..maybe they are the same but it seems like hammer doesn't take that step to extend. I think that microfaces that don't degenerate would create duplicate verts during step 4, at least thats how it seems when I visualize this happening.

I guess brush splitting and plane merging, the interactions between brushes and not just the interactions among an individual brushes planes, happens first?

[joe_rogers_11155]

...(epic explanation of vbsp working)...

that almost makes the long compile times forgivable. almost.

[Starving Hobo]

A way to make it possible to code into the map! So you could have custom player models for just one map, and things like that... Instead of needing to create a whole mod or a mod for servers which not all servers will have etc.

[Gary]

A way to make it possible to code into the map! So you could have custom player models for just one map, and things like that... Instead of needing to create a whole mod or a mod for servers which not all servers will have etc.

Code is loaded before the map...

[Starving Hobo]

A way to make it possible to code into the map! So you could have custom player models for just one map, and things like that... Instead of needing to create a whole mod or a mod for servers which not all servers will have etc.

Code is loaded before the map...

Is there no way for a map to be able to override the game code to give everyone different skins and stuff like that without the need for server plugins or mods?

[Gary]

Well, if you want to override textures, models, animations, sounds, and/or materials. You could try storing it in the same directory and with the same name as the content your trying to replace.

Like:
Default.GCF: sounds/weapons/ak47_fire01.wav
ak47_fire01.wav being what ever is default which you can't touch

Your.BSP: sounds/weapons/ak47_fire01.wav
ak47_fire01.wav being your replacement


I completely made up these directories and names for the example.

[Shrinker]

My main menu is now a plugin to the application.

:)

[gtamike_TSGK]

Hey guys,

how do you imagine good plugin support for Hammer?

I'm looking for a bit of inspiration.

https://developer.valvesoftware.com/wik ... e_Requests

[stukabomber44]

I agree with Ich666 with 3dsMax or Maya... simple exporting plugin for props, prop type, skins, ahh that would be the wet dream of any mapper/modder