I am working on a brand new Spine+Physics engine (irrelevant). Anyhow, I am trying to figure out what exactly vertices property contains in the case where there are bone influences.

The API reference says:

vertices: float[] from VertexAttachment
The vertex positions in the bone's coordinate system. For a non-weighted attachment, the values are x,y entries for each vertex. For a weighted attachment, the values are x,y,weight entries for each bone affecting each vertex.

Unfortunately I haven't found any character (from the Unity examples) that has vertex attachment (bounding or mesh) with bone influences. So, from the API text I imagine this e.g.:

VertexAttachment with 3 bone influences and 4 vertices. In this case, vertices contains:
x1,y1,w11,w12,w13, x2,y2,w21,w22,w23, x3,y3,w31,w32,w33, x4,y4,w41,w42,w43
Is this correct?
And what is the worldVerticesLength? 6?

If anyone can share an example with vertex-bone-influences I will be happy to figure out myself. Thank you!

EDIT:

The above is obviously wrong. I have checked the relevant code in SkeletonJson.c but I can't figure it out:

attachment->verticesCount = 0;
attachment->bonesCount = 0;
for (i = 0; i < entrySize;) {
   int bonesCount = (int)vertices[i];
   attachment->bonesCount += 1 + bonesCount;
   attachment->verticesCount += 3 * bonesCount;
   i += 1 + bonesCount * 4;
}

???

badlogic wrote

Check out the Raptor example, e.g. the mesh "raptor_arm_back" is a weighted, deformed mesh (many more in raptor) spine-runtimes/examples/raptor at master. Alternatively I'd suggest to setup a simple Spine project with one unweighted mesh and a weighted mesh, each with one or two triangles, then export to JSON. That will make writting your Spine+Physics engine much easier.

Thanks! BTW I didn't mention this I can't export cause I am using the trial version, or else I would have already done an example myself. I expect to get a full time job any time now so I'll be able to afford the pro version.

badlogic wrote

1. Number of bones influencing this vertex (let's call this number #bones)

2. List of #bones bone indices influencing this vertex

3. Vertex x/y coordinate

4. List of #bones bone weights

Hmm, that mustn't be right actually, here's an output I found:

"asdf": {
   "type": "boundingbox",
   "vertexCount": 3,
   "vertices": [ 2, 1, 1.67, 51.33, 0.664, 0, 71.67, 130.33, 0.336, 1, 1, 64.67, -11.67, 1, 1, 1, -66.33, -9.67, 1 ]
},

So it's:

1. Number of bones influencing this vertex (let's call this number #bones)

2. First bone index influencing this vertex

3. Vertex x/y coordinate relative to this bone

4. Weight of this vertex

5. Second bone index influencing this vertex

6. Vertex x/y coordinate relative to this bone

7. Weight of this vertex
   ...

8. #bones bone index influencing this vertex

9. Vertex x/y coordinate relative to this bone

10. Weight of this vertex

Whoa! That's complex.

Just a quick appetizer cause I am happy with the results so far - that Spine+Full Physics I mentioned. Of course there's still a lot of work to be done, but the basics are already there.

BinaryCats wrote

i mapped this out a long time ago, on this forum somewhere. but the search sucks This stuff should be in the docs

Are you talking about the Unity physics? Mine is C++ Cocos2d based. Boy you have lots of posts, it will be hard to find the exact reference you mention.

I have also played a lot with the Unity implementation but I have something more "physics-based" in mind. :-)