Hi,

in a custom HDK app I create a bgeo object. I can add a vertex attribute to my PolyPrimitive which shows up in houdini properly. Now I use the following code to set the value of a specific vertex:


gdp.addVertexAttrib( “uv”, size, type, 0 );
attr = gdp.getVertexAttribute(“uv”);

if(attr.isAttributeValid())
for( GEO_Primitive *curPrim = gdp.primitives().head(); curPrim != 0; curPrim = gdp.primitives().next(curPrim) )
for (int j = 0; j < curPrim->getVertexCount(); ++j)
{
attr.setElement( curPrim, &curPrim->getVertex(j) );
attr.setV3( UT_Vector3( … ) )
}


but the problem is that all the values turn out 0 when loaded in houdini.

Now my question is: what is the correct way of setting vertex attribute values in HDK?

Thanks for any help or hints,
David

This works fine for me.
attr_ref = gdp->addVertexAttrib(“uv”, sizeof(float), GB_ATTRIB_FLOAT,0);

FOR_ALL_PRIMITIVES(gdp, prim)
{
num_vertices = prim->getVertexCount();

for (unsigned vert_idx=0; vert_idx < num_vertices; vert_idx++)
{
vtx = &prim->getVertex(vert_idx);
vtx->setValue<float>(attr_ref, 3.5);
}
}

Thanks for your reply Graham,

I'm using version 10.0 of the HDK and there the GEO_Vertex class or any of its base classes don't have a setValue method. Are you using a different HDK version? I'll try the castAttributeData method on the GB_AttributeElem base class as soon as I'm back at work.

David

Yeah that code is for Houdini 11 only, sorry. The castAttributeData method should be the right way to go about it in 10.