Displacement surfaces [sewing and snapping]

If anyone has gotten the sew function to work, and knows how they did
it, please post here. I can't wait for the next tutorial, and it would
probably help in it's writing if someone posted anyways.

also, is there a way to get the edges to snap to other things? its
really hard to do it freestyle like the tutorial explains. edge
snapping would make the dirt fit into the area really well without
leaks and without the ugly mismatch problems.

The following is a digression:

and i still dont know where the hl2 files are, or the help file, or all
the prefabs that were listed in the official documentation are. i
thought the sdk was supposed to be fully functional after hl2 is
unlocked.

<span style="font-style: italic;">EDIT

Oh, and when i tried searching for
help on displacement surfaces, all i got was how to have sex with cds.
Not helpful guys. We all use Steam now.

</span>

What is sewing suppose to do?

It sews up the edges of two or more displacement surfaces, so that you
can make complex terrain seamlessly. The feature works fine but you
need to be careful while using it to get a reasonable effect. When you
create a displacement map, it is split up into a grid. The sew tool
will try and make the two faces you select stich themselves together by
matching the height of the edge points. If these edge points match up
nicely, then you will get a seamless terrain, if they do not, it will
try and match them up but most likely fail. Now we can see the grid on
the displacement surfaces, you will be able to check if they line up
okay far easier.

well, truth be told, i was much more entranced when the CD sex issue was mentioned.. sewing landmass's is not my idea of enthralling material :heee:

so i put two surfaces next to each other and click sew? that didn't
seem to work. even when i tried to get them really close it didn't
work. i don't understand how to properly invoke the sewing. do i need
to select both surfaces?

**confused**

Yes, select both surfaces by holding ctrl and left clicking on them
both in the 3D view. Now once you have played around with the two and
their edges aren't meeting, press the sew button and the points at the
edge should come to meet each other half way.

seems pretty simple. not working. i click sew and absolutely nothing
happens. i remember something about them having to be the same shape.
is this the brush or the face?

I found this over at the Valve ERC that might answer your question...

http://www.chatbear.com/board.plm?a=viewthread&t=514,1100788514,8114&id=729428&b=4986&v=flatold

I've a feeling it might have been your thread actually :biggrin:

hey look, you found a bug :smile:

Or rather an unconsidered option when parsing.

Crono said:
hey look, you found a bug :smile:

Or rather an unconsidered option when parsing.

That happens only when you post from Firefox (and possibly Netscape and Mozilla) as well. So it's probably some Javascript issue. If you post the same link from IE (by copy-pasting the original link) that doesn't happen. I've seen it before but Lep's not too hot on the cross-browser compatibility, so bleh.

</offtopic>

Select your fist face which you have applied displacement mapping to.
Now hold down shift and drag the new face to lay besides the other
one(just needs to look like it in top view) press sew.

taddaaa :biggrin:

/offtopic: It's nothing to do with browser compatibility, it's the bbcode thinking that commas shouldn't exist in URLs. However in teh WYSIWYG editor IE will automatically turn things like that into links, whereas Firefox doesn't have the capability, so don't you say that it's my coding that's lacking sonny jim :razz:

I found this over at the Valve ERC that might answer your question...

http://www.chatbear.com/board.plm?a=viewthread&t=514,1100788514,8114&id=729428&b=4986&v=flatold

I've a feeling it might have been your thread actually :biggrin:

Nope, not my thread. But it should help. My brushes arent the same
actually. the faces im using are both rectangular, but one is
rectagular on all sides, and the other is a wedge. they are also at
different levels. i'll see what i can come up with.

ok, i actually got it to work. its kinda funky in the way it works. as far as i could figure:

1 the faces you use have to be rectangular (already established)

2 the two edges you want to sew have to be identical in SHAPE (on the brush)

ie: if you have a wedge, and want to sew it to
another wedge, and have the triangular sides touching, one brush can be
smaller, as long as its in exactly the same proportion as the other
one. so you can have part of a big brush sew to all of a small one of
half its size.

2.5 you can sew a displacement surface to a normal brush, as long as
the base brush of the surface follows the rules outlines above
(basically the same as two displacement brushes, only one isn't an
actual disp brush)

3. The edge in question must be exactly the same in the original
brushes. this means you cant move one brush of even identical shape and
size up one unit and hope the top faces sew. nope, doesn't work.

this greatly limits the usefulness of sewing, but hey, it's better than not having it.

btw ReNo, your input was the most helpful, but I can't give you credit as it stands, and I can't do it to myself either :rolleyes:

Oh, do we let displacement surfaces intersect with other surfaces or
brushes? does this cause compile time increases or in game lag?

Oh, do we let displacement surfaces intersect with other surfaces or
brushes? does this cause compile time increases or in game lag?

Works fine for me... only proplem is that you wan by no means carve through it :biggrin:

I think its acceptable, but don't go overboard with it. I believe that
if part of a displacement surface is rendered then the whole thing is,
so don't, for example, just stick one over your entire level and use
that for all your ground.

A couple of additional questions regarding displacement surfaces:

• What exactly do the subdivide button do?

• If the outer edge of the surface becomes unaligned to the grid - is there anyway to have it snap to grid?

• And finally, have anyone figured out a good way to create a tunnel through a "displacement hill"?

Subdivide, I imagine, would split each of the existing grid "faces"
into smaller chunks, giving you more points to play with. I've not
tested this out yet, so I've no idea if thats correct or not.

I don't really see how an edge of the surface could become unaligned
from the grid, except in the case that you change the direction of
"paint geometry" to something other than surface normal (which, for
most scenarios, is all you need). If you give me an example I
might be able to better help.

I'd imagine the only way to create a tunnel through a hill would be
using multiple displacement surfaces that you would sew together. A
displacement surface cannot be 'pierced' with a hole, which would be
necessary to create a tunnel.

Yeah - that's pretty much what I thought subdivide does as well - but
whenever i select a displacement surface and click it, nothing happens
...

As for the edge becoming unaligned - I've experience that happening
while reducing the "power of", on surfaces with some high spikes
... It can also happen if you, as you stated, change the morph axis ...

As for the tunnel - I've tried several variants and they all pretty
much suck - you end up with glitches between the various surfaces -
especially the one on the top of the tunnel ... The only solution I've
found so far is to make up the terrain on top of the tunnel by world
brushes and then lining up the vertices of the displacement surfaces
manually. This works, but isn't really great ...

Ehm, tajgenie, do you Snap to Grid or do you work freely off the grid? Having Snap to Grid on makes sewing really easy...

Displacement mapped faces do have to be rectangular, but normal faces
don't have to be rectangular to be able to sew a displacement map to
them. It's all about the edge their base brush shares with another
brush.

Neither do they have to have the same shape. For example, I sewed two
displacement maps (256x256 size both) with one triangular brush
(512x512 cut in half). Since the displacement maps edges were together
the same width as the triangular brush' edge, sewing was no problem.

Subdivide currently does nothing as far as I know, but you can alter
the number of subdivisions with the Power option of the surface.
Clipping displacement mapped brushes also makes them maintain their
previous shape, but since the Power of both new dismaps is still the
same, the number of triangles is doubled, thus the shape is more
detailed.

As for tunnels, you can make more than one face of a brush a dismap.
Just select the faces you want and then create a dismap. This is very
handy for aligning cliffs with their top and things like that. Tunnels
could be done like this too. Sewing here is especially easy as two
faces from the same brush automatically share an edge.

Ehm, tajgenie, do you Snap to Grid or do you work freely off the grid? Having Snap to Grid on makes sewing really easy...

Displacement mapped faces do have to be rectangular, but normal faces
don't have to be rectangular to be able to sew a displacement map to
them. It's all about the edge their base brush shares with another
brush.

Neither do they have to have the same shape. For example, I sewed two
displacement maps (256x256 size both) with one triangular brush
(512x512 cut in half). Since the displacement maps edges were together
the same width as the triangular brush' edge, sewing was no problem.

I always snap. Snapping is super :biggrin:

As for sewing, I experimented with every combination i could think of
at the time, and my results are posted above. Maybe I was slightly
unclear in it:

I think you are saying that adjacent faces during a sew don't need to
be the same as long as the edge is the same. I can see how this could
work, I need to test that too. However, the edges do not have to have
the same length though. you can sew a huge cube to a small one, but
only the overlapping edge of the brush will be sewed, and the rest of
the huge cube will remain as is. If you got it to work the way you
said, though, I guess it works. :smile:

Indeed, they don't have to have the same lenght, but then most of the times only a few vertexes will be aligned.

And indeed, it's all about the edges of the base brushes.

What exactly is a "displacement surface?" Is it just another name for "Brush" If not, what is the difference and how do i make a displacement surface? I need to make a realistic hill and I don't know how. Also, can a regular brush overlap a displacement surface? cheers

http://www.snarkpit.com/editing.php?page=tutorials&game=HL2&id=112

I haven't read anything of much use about whether you can overlap
brushes and displacement surfaces, but I'd assume its ok for now.

I assume the same as well, ReNo. After noclipping through some HL2 maps
I think it's perfectly ok to do so. Dismaps aren't cut when a brush
touches it, instead, it just continues. I think it must be seen as a
replacement for the brush you inserted and not as a bunch of faces like
in original HL, e.g. vertexed terrain, in terms of face-splitting and
the like.

I also think the base brush of a displacement map is used for VIS and
determining leaks, although I haven't tested with that yet.

So I found the answer to my questions regarding subdivide and tunnels, over at mapcore.net - courtesy of Zaphod ...

I figured I'd make some pics of the process as it might be a little
difficult to understand it if I just explained it in words ...

First make a hollow cube like this:



Make sure that the edges of the inside faces line up like this:



Then create displacements of all the 4 inside faces like this:



And finally - with all 4 displacements selected click the "subdivide" button - and you should end up with this:



You can also use this on outside corners as well as combine inside and outside corners like this:



So now we know what the subdivide button does, and it should prove very helpfull in the making of tunnels, caves etc ...

I haven't really had time to explore any further uses for this yet -
but I'll mention this - you can tick off "Auto subdivide" in the
displacement window ...

Thanks for that, it had me stumped to be honest :smile:

NP man - You should add this to your displacement tuts ...

:O :O :O

Sewing = L337

One question: Can A displacement object seal leaks? Does the hull of the displacement decide whether it seals or not, or is it the actual "polygon bending"?

From what I understand it doesnt seal leaks as the brush doesn't block
vis when it's turned into a displacement - it's turned into an entity
if you like ....

Rectify this prob by slapping a brush the same size as the base brush
of the displacement, textured with "nodraw" under it, to seal off the
area ...

haha... boo hoo... i spent a few hours on a few displacement surfs
because i was trying to keep them inside the level... maybe i should
have tested it first... anyway, good job with the tutorials and such.
even though i wasted all that time its better than it could have
been... i would have made the dirt in my level the old fashion way if I
not read your tutorial reno...

Hey thanks for the link. I have started Displacement-ing already. I have a great map going now. I hope to post an update in the maps section when it's about half done, just to let folks know about it.

On another note, was anyone else really not satisfied with the ending of HL2? It seemed really anticlamitic to me.