Hint brushes, what they do and some examples on use.
When compiling the map with kpbsp.exe it will split the map into
invisible 'areas' and create a file containing these.
These areas are called portals and are stored in a seperate file
The purpose of these portals are to split up the world into sections
to allow for kpvis.exe(VIS) to calculate weather you can or cant
see an area.
The use of a hint brush is to splits these portals along every
face of the brush that has the hint texture (textures/common/0_hint).
The map needs to test if the single portal(that you stand in)
can/cant see every other portal in the map.
This is why VIS takes a long time if the map was not created properly,
espicaly using cones/cylinders that are not made into a detail
Most of the time a portal will be created as simple as can be,
usually to long, the longest portal you will find is 1024 units
This is because bsp automatically divides map along the X,Y axis
every 1024 units, it also makes tris (triangles) along these lines.
I have also noticed that if a lot of brushes have been made in
same direction, bsp will split the portals in those directions
You can view these default splits on 1024 in editor by setting
filters(shortcut F) to show 'Blocks'.
|In pic 1 you can see the portals (purple)
with players in them (red) . Even though the players cannot
see 1 another, the portals that they are in can see each other
so tris around the corner will get rendered (see pic 6). if
I place a hint brush to split the portals (purple ones)along
the inner wall, it will make VIS think that the portal than
I am standing in CANNOT see the portal the other payer is
standing in, thus not rendering what's contained in that portal
and beyond. Players, weapons, armor and most importantly triangles
wont get rendered, this is what causes bad frame rates, especially
when it can be avoided
|pic 2 is with q3rad's portal viewer portraying
the purple portals, that are in pic 1
See the Q3Radiant setup guide.
|Pic 3 is my hint placement to brake up the
Skip texture will not make portal splits
Sometimes with a hint placed, you will notice it made tris different,
its not designed to effect tris directly, but because it changes
the map structure it will compile brushes in a different order.
Also note if a HINT brush it placed threw a detail brush, it WILL
split it (make tris).
|Pic 6 is not using a hint brush, you are standing
in a portal that can see were the bin is. after we split it
with a hint(as in pic 3).
|in pic 7 i have placed a hint brush and you
can see that the bin does not get rendered.
|There is a different technique you could use
when getting pushed for r_speeds.
In pic 8 you can see that the hint is placed on an angle,
the principle is still the same, were the purple portals still
cannot see 1 another but it allows player to move further
towards the next room
|Pic 9 is another example of player not being
able to see 1 another, but the area they stand in(portal)
is able to see the other portal.
Pic 10 shows the player standing inside the purple portal.
As shown in pic 8.
Thi picture shows how effective my hint placement was, I can
almost walk up to corner and its still not rendering the bin.
If there was a huge and detailed room after bin, then you
understand how effective this will be on gameplay.
|In pic 11 I
have walked just past the angled hint brush.
Entering the light blue portal in pic 8.
Note that it DID NOT create tris along the hint placement.