What are "waterindices"?

Waterindices are a part of Source maps. (I understand mapping questions should be posted in the maps section, but this seems to be beyond mappers knowledge so I am asking here).

The map compile log states that:
waterindices 61647/65536 123294/131072 (94.1 VERY FULL!

Seems like an easy enough problem at first, but it seems that NOBODY knows what "waterindices" are.

From Rof (writer of VMEX):

The Primitives (37), PrimVerts (38) and PrimIndices (39) lumps are used in reference to "non-polygonal primitives". They are also sometimes called "waterstrips", "waterverts" and "waterindices" in the SDK Source. Their use is uncertain. Faces of water brushes are not always associated with them, and they are often associated with faces that are nowhere near water. Instead, they seem to be used to break-up faces with colinear vertices into smaller triangles.

This paragraph is THE ONLY information about waterindices on the entire world wide web. Unfortunately, Rof does not know exactly what waterindices are.

Are there any coders or moderators who can provide some insight as to what "waterindices" might be?

These are indices that are stored to represent various tessellations that vbsp does. When they were first created they were only used to subdivide water meshes (that's why they are often referred to as water indices). In HL2, they are only used to fix cracks in the world. Normally each face is fan-tessellated, so no indices are stored, but with several t-junctions on the face's edges this is often not possible and a separate tessellation is generated and stored.

It has nothing to do with shaders or any limitations there.

Jay

t-junctions are edges with more than two collinear verts. This happens when dissimilar geometry meets sharing an edge, vbsp automatically adds all verts along the edge to each polygon sharing the edge to avoid cracks. vbsp has a -notjunc option that will skip this process, but that will leave you with cracks in your level. You probably want the t-junctions fixed. Cracks usually look like sparkling edges (bright pixels in the skybox showing through).

There are several references on t-junctions online as it's a general problem when processing geometry for any rendering engine. It's not unique to anything specifically in Source.

Jay

@Dema: Jay said "It has nothing to do with shaders or any limitations there. " Unless something bad actually happens when you hit 100%, I think you can safely ignore this as per what Jay said.

http://parashift.com/c++-faq-lite/
http://againsttcpa.com/what-is-tcpa.html
http://research.att.com/~bs , cgsociety.org
over-yonder.net/~fullermd/rants , acronyms.ch

...Dema, is this a CS:S Surf map by chance?

Not at all SDK Code related, correct? Engine related problem?

SDK Nuts