[Guide] Why you're displacements won't sew + some

Dark

L4: Comfortable Member
Nov 27, 2009
159
137
[Guide] Why your displacements won't sew + some

1.Displacements must share an edge
While this is common knowledge for most mappers it may be a little confusing for someone new to hammer. When we talk about displacements sharing an edge it is the Origin to keep in mind.
(A.) How to find a displacement Origin, and basic sewing.
Finding an origin is quite easy, all you have to do is select the displacement in question.
displacments1.png

In the top half of the picture we can see how this displacement will look in game, and on the bottom half we see the tessellated displacement over a normal brush. This normal brush is where the displacement started from (a.k.a: the origin) This is what we want to look at when we get ready to sew this displacement to an other.
displacments%202.png

In the top half we ca see that the displaced faces are not close together, however because the origins are touching they will sew together.
displacments%203.png


2.Displacements do not have to be the same size
This one is fairly straight forward, for displacements to sew they must be the same size or exponentially bigger or smaller on the side you are sewing. For instance these will sew together.
displacments%204.png

displacments.png

(Provided the sides were touching)
While this will not
displacments%205.png


3. Manipulating origins
This is how you can make more advanced displacements easier. The only real way to do this is with vertex manipulation, don't forget that vertexes and displacements go hand in hand. This is the way I would have done a smooth cliff with just the basics of displacing.
displacments%206.png

As you can see I used three brushes for this, and the middle had to be pushed very far away from the origin. With vertex editing this same kind of displacement is possible with fewer brushes and less work.
displacments%207.png

(The origin is highlighted in yellow) much less work was required and the displacement face is much closer to the origin. This is a technique used in Gordge as illastrated here (and probably many other maps as well)
displacments%208.png


4. Power, and Size Matters
Higher power displacements mean more cost to the machine, if you can do it on a lower power, then do it. As void says “Don't use 4-power displacements, ever.” This is because high vertice density can cause crashes, however vertex density is relative to the size of your brush, if you have a massive brush to displace, and power 3 is not cutting it then a power 4 displacement may be in order. This also means that displacing a very small brush with cause that same vertice density crash.
displacments%209.png
< This will crash tf2
A general rule of thumb i have come up with from looking at lumberyards displacements is that you want no fewer then 64-32 units between vertices.
displacments%2010.png

If you come across a spot where you need more vertices for your displacement instead of using power 4 simply split the brush in half. This will save more of the computers power for other things you want. Just remember with this rule, if it can be done with a lower power then change it down. (Just in case you are not aware, changing the power around does not mean that you have to destroy, and re do it.)
displacments%2011.png

displacments%2012.png


5. Final thoughts
While these things are common knowledge for most people they are very important things to know when doing displacements. Now I would like to touch on a few other things about displacements.
Displacements do not have to be the same power to sew, while they will look better if they are it is not necessary.


Other links regarding displacements that I found helpful:
http://forums.tf2maps.net/showthread.php?t=11308&highlight=displacements
http://forums.tf2maps.net/showthread.php?t=798&highlight=displacements

And Remember Kids Mashing Them Together is Never The Answer
 
Last edited:

grazr

Old Man Mutant Ninja Turtle
aa
Mar 4, 2008
5,441
3,814
Displacements will also sew if they are 1/2 or 1/4 the size of the shared edge of another displacement. Show some examples of this, this is important and not really a "final thoughts" kinda aspect to displacements. Give it its own section in your article. Plus, explain why people shouldn't use power 4 displacements, or super small displacement brushes (high vertice density can cause crashes).

It's also nice to back up your statements and points with Valve examples.

Also, i'm pretty sure i've managed to sew displacement edges that did't share the same Z-plane alignment.

Edit: and it's "your" not "you're", regarding the thread title. I wouldn't normally act the over vigilante grammar police but it's in the thread title which is a little more important.
 
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cyked

L3: Member
Dec 18, 2009
132
89
Thanks for the article. especially the links on displacements. Maybe now I can actually build my rock map. :)