simple skinning

[sturatt]

Im trying to learn about skinning, so i am modifying a smiple program that i have that just draws colored triangles.

I've added all the parts that i thought i needed to get it to render, but when i compile with all this stuff, i get a black screen.

Here is the stuff ive added:

i changed my vertex to have the weights:

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typedef struct pspVertex {
	float weights[8];
	float u,v;
	unsigned int color;
	float nx, ny, nz;
	float x,y,z;
};

when i read in the vertex data, i set all of weights to 0.

I added this small section right before i call sceGuDrawArray to setup the bones

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ScePspFMatrix4 mat[8];
		for &#40;int i=0; i<8; i++&#41;
		&#123;
			gumLoadIdentity&#40;&mat&#91;i&#93;&#41;;
			sceGuBoneMatrix&#40;i, &mat&#91;i&#93;&#41;;
			sceGuMorphWeight&#40;i, 1.0f &#41;;
		&#125;

and i changed my sceGuDrawArray to have GU_WEIGHTS(8)|GU_WEIGHT_32BITF

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sceGumDrawArray(GU_POINTS, GU_WEIGHTS(8)|GU_WEIGHT_32BITF|GU_TEXTURE_32BITF|GU_VERTEX_32BITF|GU_NORMAL_32BITF|GU_COLOR_8888|GU_TRANSFORM_3D,
			meshes[x].numVertices, 0, meshes[x].vertices);

why would these things stop my model from rendering?

[rapso]

the new vertex is

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for each weight
  newpos += originalpos*matrix*weight

all weights to 0 accumulates to 0 as well.
the sum of all weights should be 1.

[Raphael]

Also, morphweight != skinweight.

[sturatt]

Thanks for the replys :)

After reading what you said, i went back and changed it so that the first weight on each vertex is 1.0f. With the first bone matrix being an identity matrix, shouldn't my geometry show up unchanged?

@Raphael
Yeah, i thought so, but i was just throwing stuff in there to try and get some trianges =D. I was a little confused though, morphing is when you give several vertices to interpolate between right? The reason i wasnt so sure is because randomly in the skinning sample in the sdk, he throws a guMorphWeight in there.

[sturatt]

I still dont know what im doing wrong. It seems like my model should show up just as it did before, but adding these things seem to stop it from showing up at all...


I added hte weights to the vertex structure:

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typedef struct pspVertex {
	float weights[8];
	float u,v;
	unsigned int color;
	float nx, ny, nz;
	float x,y,z;
};

set each weight to 1.0f/8.0f

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for &#40;int h=0; h<8; h++&#41;
			&#123;
				meshes&#91;x&#93;.vertices&#91;y&#93;.weights&#91;h&#93; = 1.0f/8.0f;
			&#125;

Setup the matrices before each render, and added the GU_WEIGHTS and GU_WEIGHT_32BITF to the render type

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ScePspFMatrix4 mat[8];
		for &#40;int i=0; i<8; i++&#41;
		&#123;
			gumLoadIdentity&#40;&mat&#91;i&#93;&#41;;
			sceGuBoneMatrix&#40;i, &mat&#91;i&#93;&#41;;
		&#125;

		sceGumDrawArray&#40;GU_POINTS, GU_WEIGHTS&#40;8&#41;|GU_WEIGHT_32BITF|GU_TEXTURE_32BITF|GU_VERTEX_32BITF|GU_NORMAL_32BITF|GU_COLOR_8888|GU_TRANSFORM_3D,
			meshes&#91;x&#93;.numVertices, 0, meshes&#91;x&#93;.vertices&#41;;

should just those things stop my geometry from rendering? when i commend all the new stuff above out, it draws just fine. I also tried setting weight[0] to 1.0f and the rest to 0, but still nothing.

Thanks,
Stu

[sturatt]

Nobody knows what im doing wrong?