yang686526

向高手求救getmodeltoeyetransform函数
向高手求救getmodeltoeyetransform函数
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);
}
在这个函数中
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);
}
有getmodeltoeyetransform(mat);和verts[i].transformby(mat) 起的什么作用啊？ 有人给详细解释一下吗？ 如何控制视图的？