Added new method to partition heighfield

- added layer based heighfield partitioning
- the method is a bit slower than monotone partitioning, but does not
suffer from the long thin ploys
- the method partitions the heighfield into non-overlapping areas, but
does not try to resolve holes
- improved contour hole merging so that it can properly handle all
kinds of holes
- improved polygon triangulation to handle overlapping segments
- improved small and long polygon detail mesh generation
- updated samples to include all 3 partition methods and little
documentation to help to choose between them
This commit is contained in:
Mikko Mononen
2014-06-13 13:25:01 +03:00
parent bbcb11fd14
commit a89bb843d7
12 changed files with 1167 additions and 235 deletions

View File

@@ -72,14 +72,12 @@ class NavMeshTileTool : public SampleTool
Sample_TileMesh* m_sample;
float m_hitPos[3];
bool m_hitPosSet;
float m_agentRadius;
public:
NavMeshTileTool() :
m_sample(0),
m_hitPosSet(false),
m_agentRadius(0)
m_hitPosSet(false)
{
m_hitPos[0] = m_hitPos[1] = m_hitPos[2] = 0;
}
@@ -1038,32 +1036,69 @@ unsigned char* Sample_TileMesh::buildTileMesh(const int tx, const int ty, const
for (int i = 0; i < m_geom->getConvexVolumeCount(); ++i)
rcMarkConvexPolyArea(m_ctx, vols[i].verts, vols[i].nverts, vols[i].hmin, vols[i].hmax, (unsigned char)vols[i].area, *m_chf);
if (m_monotonePartitioning)
{
// Partition the walkable surface into simple regions without holes.
if (!rcBuildRegionsMonotone(m_ctx, *m_chf, m_cfg.borderSize, m_cfg.minRegionArea, m_cfg.mergeRegionArea))
{
m_ctx->log(RC_LOG_ERROR, "buildNavigation: Could not build regions.");
return 0;
}
}
else
// Partition the heightfield so that we can use simple algorithm later to triangulate the walkable areas.
// There are 3 martitioning methods, each with some pros and cons:
// 1) Watershed partitioning
// - the classic Recast partitioning
// - creates the nicest tessellation
// - usually slowest
// - partitions the heightfield into nice regions without holes or overlaps
// - the are some corner cases where this method creates produces holes and overlaps
// - holes may appear when a small obstacles is close to large open area (triangulation can handle this)
// - overlaps may occur if you have narrow spiral corridors (i.e stairs), this make triangulation to fail
// * generally the best choice if you precompute the nacmesh, use this if you have large open areas
// 2) Monotone partioning
// - fastest
// - partitions the heightfield into regions without holes and overlaps (guaranteed)
// - creates long thin polygons, which sometimes causes paths with detours
// * use this if you want fast navmesh generation
// 3) Layer partitoining
// - quite fast
// - partitions the heighfield into non-overlapping regions
// - relies on the triangulation code to cope with holes (thus slower than monotone partitioning)
// - produces better triangles than monotone partitioning
// - does not have the corner cases of watershed partitioning
// - can be slow and create a bit ugly tessellation (still better than monotone)
// if you have large open areas with small obstacles (not a problem if you use tiles)
// * good choice to use for tiled navmesh with medium and small sized tiles
if (m_partitionType == SAMPLE_PARTITION_WATERSHED)
{
// Prepare for region partitioning, by calculating distance field along the walkable surface.
if (!rcBuildDistanceField(m_ctx, *m_chf))
{
m_ctx->log(RC_LOG_ERROR, "buildNavigation: Could not build distance field.");
return 0;
return false;
}
// Partition the walkable surface into simple regions without holes.
if (!rcBuildRegions(m_ctx, *m_chf, m_cfg.borderSize, m_cfg.minRegionArea, m_cfg.mergeRegionArea))
{
m_ctx->log(RC_LOG_ERROR, "buildNavigation: Could not build regions.");
return 0;
m_ctx->log(RC_LOG_ERROR, "buildNavigation: Could not build watershed regions.");
return false;
}
}
else if (m_partitionType == SAMPLE_PARTITION_MONOTONE)
{
// Partition the walkable surface into simple regions without holes.
// Monotone partitioning does not need distancefield.
if (!rcBuildRegionsMonotone(m_ctx, *m_chf, m_cfg.borderSize, m_cfg.minRegionArea, m_cfg.mergeRegionArea))
{
m_ctx->log(RC_LOG_ERROR, "buildNavigation: Could not build monotone regions.");
return false;
}
}
else // SAMPLE_PARTITION_LAYERS
{
// Partition the walkable surface into simple regions without holes.
if (!rcBuildLayerRegions(m_ctx, *m_chf, m_cfg.borderSize, m_cfg.minRegionArea))
{
m_ctx->log(RC_LOG_ERROR, "buildNavigation: Could not build layer regions.");
return false;
}
}
// Create contours.
m_cset = rcAllocContourSet();
if (!m_cset)