2 point clipping for new mappers

(sock) #1

This started out as a simple tutorial idea on 3 point clipping and then I realised … in order to explain 3 point clipping I need a frame of reference, 2 point clipping!

Then I slipped into tutorial hell trying to figure out ways of explaining the priniciples of clipping in ways that are simple and direct. Well after 1 week of constantly reading/re-writing/reading/hating this clipping tutorial, its finally ready.

Be warned this is very basic stuff, (with alot of images) but it nicely explains everything ready for me to complete the 3 point clipping tutorial (The original reason for this tangent) and then move back to scripting … talk about going round in circles … :wink:

Direct link: http://www.planetquake.com/simland/ldr1_1/index.html

LDR 1.1 index link: http://www.planetquake.com/simland/ldr1_1/index.html

As always all feedback and comments welcome, remember its a living breathing document which can easily change. Probably some typo’s are lurking in that mess of word and images.

Enjoy
Sock
:moo:

(The Wanderer) #2

make sure you update us when you get that 3 point clipping in.

(sock) #3

Ironically there is only 2 difference between 2 point clipping and 3.

  • One more extra marker (blue dot)
  • The 3rd marker specifies the cutting direction.

Thats it! IMHO the worst thing about 3 point clipping is actually understanding clipping in the first place. Its knowing what the editor is trying to do with the cutting angle, direction and side. As I found out (possible the hard way) 2 point clipping is the hard bit! :wink:

Sock
:moo:

(hummer) #4

GJ on the 2-point clipping tutorial… I’ll be waiting for the 3-point clipping tutorial. For whatever reason, 3-point clipping is always a pain for me, so I must be doing something wrong.

(kat) #5

another important tute… I’ll put some linkage up for these news ones

(MuffinMan) #6

at our wip - “die eskorte” i did a shitload of structures in non-90° angles (i had to) since then i somehow even like 3-point clipping - hmmm… seems like i am doing something wrong :smiley:

(kat) #7

you’re a jedi master now…!!! although some would liken it to S&M… :eek2: :smiley:

(redfella) #8

The one thing that I have never understood about 3-point clipping is this… Why can’t a user just switch to another view (xy, zx, etc) and then just use 2-point clipping? Isn’t that essentially the same thing as just 3-point clipping…?

Maybe I just don’t understand 3-point clipping because I never use it.

(Loffy) #9

Hi
I have a confession: I have no clue how to 3-point clip the proper way. When I 3-point clip, I set two points in one 2D window, the third point in another 2D windown and then I just pull the blue dots left/right/up/down in the 2D windows. I monitor the result in the camera view window, and when it looks OK i hit Return.
There is a need for 3-point cuts sometimes, when I map.
// L.

(michi.be) #10

some people may find this video-tutorial intersting:

http://www.level-designer.de/modules.php?op=modload&name=Sections&file=index&req=viewarticle&artid=132&page=1

(Drakir) #11

What 3 point clipping can be usefull for:


This is pretty easy to do with just 2 point clipping.


This is also easy to do with 2 points clipping.


But if you want to do this 3 vertex corner u need 3 point clipping.


Above View of the 3 examples.

(kat) #12

becasue you’re basically still 2pt clipping, you always need that 3rd point to make it 3pt clipping, otherwise you’re just clipping along a given plane (along a particular XY axis).

My set up is the same as socks’ floating windows (one big grid and camera window) and I personally find it best to just place all 3 clipping points ‘anywhere’ in only one view (XY) and then left click hold and move them into place. When you flip to another viewport (ZX) using Shift+TAB you can still move the clip points relative to your original placement.

Use the 4 window set up, if you place your 1st 2 points in one view and then the 3rd in another the clip mechanics will orientate themselves to a sort of ‘average’ between the windows (that’s not what it actually does but it’s the best way I can think to explain it). You’ll get a slightly differnt result (I think) if you place all 3 in one window and then use the others to just move the points about.

(hummer) #13

This can be done with edge dragging and 2-point clipping. I just did it in a under a minute to make sure :slight_smile: Of course, maybe with 3 point clipping it would only take a few seconds…

I mean, I can do 3-point clipping and I use it from time to time…it just feels clumsy to me and I find others ways to get the same effect. What would be nice is a demonstration of 3-point clipping techniques, and instances of why 3-point clipping is useful…

However, I just saw that the new patch clipping stuff ydnar has been working on has been added new the lastest release of GTKRadiant (1.4?)… so maybe I won’t have to beome an 1337 3-point clip ninja :slight_smile:

(kat) #14

Be careful dragging vert/edges though as you run a greater risk of introducing brush errors on odd shaped brushes…!!. One of the main reasons for clipping is the ‘clean’ cuts you get that don’t tamper with the rest of the brush.

(ydnar) #15

I added a 3-pt clipping helper to GtkRadiant 1.4. Set up a single patch mesh with nodraw, and vertex edit it until it’s just a square or a triangle.

Select it along with any brushes you want to clip, and the 3-pt clipper will default to the plane of that patch.

Since patch meshes won’t bork when vertex edited, you can move, rotate, vertex edit the clipper patch all you want. Since it’s visible, you can see where the clip plane will be.

y

(joop sloop) #16

Patch clipping? As in clipping an actual patch, now that would be awesome :slight_smile:

(chavo_one) #17

Patch clipping, as in using a patch to visualize and perform the clipping.

http://shaderlab.com/gtkradiant/clipper.jpg