Pretty Poly Editor Documentation
I. PPE Manual - 6. Working with the editor - e. Building modes
Please read
"overview over primitives" first.
When you are in a building mode and not in a selection mode, then, every time you click,
something is created. While you read this, try creating a linestrip. When you click for
the first time, a vertex is created. afterwards, you have a rubberband-effect showing
where the next vertex would be created if you left-clicked now. Click left several times
in different places to see what happens. When you want to do a second, unconnected
linestrip, you have to go out of builder-mode and then into it again. Try to create some
points, lines, linestrips and lineloops.
Now let's create a few polygons. All polygons have front- and backfaces. In the
"standard mode" of PPE, polygons facing you with their frontface are filled, whereas
the backsides of polygons are rendered as wireframe (you only see the edges of the
polygon). You can create polygons facing you or facing away, depending on whether you
create the vertices in a counterclockwise or clockwise order.
Lets try to create a triangle facing you. Go into build-triangle-mode and
click two times. This way you have fixed the first "base leg" of the triangle.
When you now move the cursor, you will see a "preview" of the triangle that would be created
if you clicked here. When the direction of vertex 1 -> 2 -> 3 is clockwise, you will
see the triangle as wireframe and it would be created facing away from you and vice versa.
Create a few triangles. Now try quads and polygons. You simply have to click on the vertices along the rim
one after the other. When you are in polygon-mode and clicked the last vertex,
go out of build-polygon-mode to tell PPE that there are no more vertices to this polygon.
It will then be completed.
Now lets go for a TriStrip. Say we want to do the following form as a TriStrip.
You now have to think about how to subdivide the form into triangles (called tesselation)
and where to start. Unfortunately, there are a number of mistakes you can do,
see
"discussion topics: Building modes".
However, in this chapter I want to show you how to do it right :-).
A correct tesselation is shown in the next image:
If you start at vertex 1 and click on them up to vertex 8, then
everything should be fine. You should notice that the first triangle
was orbited
in counterclockwise motion. This means that the strip will be facing you,
even so it seems the next triangle is is orbited clockwise.
The n.th triangle will always have the edge between the last two vertices
as one edge. For example, when you do the second triangle, you cant
do it (using TriStrips) in such a way that it borders on the edge
1-2 or 1-3, it has to border on 2-3. Also, the next vertex (4, in this case)
has to be "on the other side", that is, regarding to the edge 2-3
the vertices 1 and 4 are on different sides. If you would click into the same side again,
you would get a backface.
You can also do the same form as a QuadStrip. This time, it is fairly obvious, how to do
the subdivision into the three faces. However, don't try to "orbit" the quads (like
you would do when you build single quads). Instead, go in a criss-cross-motion like
you already did when building the TriStrip. You can see the order in which to
create the vertices in the next picture:
