Dear friends, I am following the recast code, here I am stuck in.

[Jack]

I understand the obj files are to be read by identifiers followed by values. Then I am up to the subdivide function,

static void subdivide(BoundsItem* items, int nitems, int imin, int imax, int trisPerChunk,
                      int& curNode, rcChunkyTriMeshNode* nodes, const int maxNodes,
                      int& curTri, int* outTris, const int* inTris)
{
    int inum = imax - imin;
    int icur = curNode;
   
    if (curNode > maxNodes)
        return;

    rcChunkyTriMeshNode& node = nodes[curNode++];
   
    if (inum <= trisPerChunk)
    {
        // Leaf
        calcExtends(items, nitems, imin, imax, node.bmin, node.bmax);
       
        // Copy triangles.
        node.i = curTri;
        node.n = inum;
       
        for (int i = imin; i < imax; ++i)
        {
            const int* src = &inTris[items[i].i*3];
            int* dst = &outTris[curTri*3];
            curTri++;
            dst[0] = src[0];
            dst[1] = src[1];
            dst[2] = src[2];
        }
    }
    else
    {
        // Split
        calcExtends(items, nitems, imin, imax, node.bmin, node.bmax);
       
        int    axis = longestAxis(node.bmax[0] - node.bmin[0],
                               node.bmax[1] - node.bmin[1]);
       
        if (axis == 0)
        {
            // Sort along x-axis
            qsort(items+imin, inum, sizeof(BoundsItem), compareItemX);
        }
        else if (axis == 1)
        {
            // Sort along y-axis
            qsort(items+imin, inum, sizeof(BoundsItem), compareItemY);
        }
       
        int isplit = imin+inum/2;
       
        // Left
        subdivide(items, nitems, imin, isplit, trisPerChunk, curNode, nodes, maxNodes, curTri, outTris, inTris);
        // Right
        subdivide(items, nitems, isplit, imax, trisPerChunk, curNode, nodes, maxNodes, curTri, outTris, inTris);
       
        int iescape = curNode - icur;
        // Negative index means escape.
        node.i = -iescape;
    }
}

What does it do? Any reference materials I can take a look at?
Thanks
Jack

[Mikko Mononen]

The ChunkyTrimesh is a simple acceleration structure which I use for the demos to make the tile generation faster. It is a simple AABB tree.

For your own implementation you don't need any of that. The important bit of feeding in triangles to Recast is the rcRasterizeTriangle* functions. They feed in the input triangles. You can call one of the indexed triangles methods or even the one that rasterizes just one triangle.

--mikko

Jack

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[Jack]

Now I am up to "spans", what do spans do?
Jack
 

[Jack]

BTW, the contour will be a poly if the trial fit doesn't "fit" in a "square".
Like to say if the obstacle is cutting a corner of a square, there must be a contour to set up, then it is of type "poly"
This is my assumption. Correct me if I am any wrong
Thanks
Jack

 

[Mikko Mononen]

Keep on following the example code... as you can see from the example code, there is a visualization of each step in the demo too, that should help you understand how things work.

--mikko

On Sun, May 12, 2013 at 7:40 PM, Jack <lucky7...@yahoo.com.hk> wrote:

Now I am up to "spans", what do spans do?

Jack
 

--

[Ben Hymers]

Here's a handy resource that explains the process in a slightly more human-friendly way than code:

http://www.critterai.org/nmgen_study