问个函数getmodeltoeyetransform
 

问个函数getmodeltoeyetransform
问个函数getmodeltoeyetransform
//下面是自定义实体实现父类虚函数的方法
asdkcoordsamp::viewportdraw(acgiviewportdraw* pv)
{
pv->subentitytraits().setfilltype(kacgifillalways);
const int count = 3;
acgepoint3d verts[count];
verts[0] = acgepoint3d(0.0, 0.0, 0.0);
verts[1] = acgepoint3d(1.0, 0.0, 0.0);
verts[2] = acgepoint3d(1.0, 1.0, 0.0);
// draw model space line segment.
//
pv->subentitytraits().setcolor(kblue);
pv->geometry().polygon(count, verts);
// compute its representation in eye space.
//
acgematrix3d mat;
pv->viewport().getmodeltoeyetransform(mat);
for (int i = 0; i < count; i++) {
verts[i].x += 0.01;
verts[i].y += 0.01;
verts[i].z += 0.01;
verts[i].transformby(mat);
}
// display the eye coordinate equivalent of the
// model space polygon.
//
pv->subentitytraits().setcolor(kgreen);
pv->geometry().polygoneye(count, verts);
// convert from eye to display coordinates.
//
for (int i = 0; i < count; i++) {
verts[i].x += 0.01;
verts[i].y += 0.01;
verts[i].z += 0.01;
//verts[i].transformby(mat);
}
// draw the display space equivalent of the
// model space polygon.
//
pv->subentitytraits().setcolor(kred);
pv->geometry().polygondc(count, verts);
}
复制代码
上面的代码中下面两句起什么作用？getmodeltoeyetransform（）谁能给出详解。
pv->viewport().getmodeltoeyetransform(mat);
verts.transformby(mat);
我感觉是在控制视图的 去掉后动待观察 图形位置有变，具体请达人解决