使用WPF绘制3D线

Question

We all know there are no native functionality within WPF 4.5 to draw pure lines in 3D space on a viewport3D.

And I'm aware of the fact there are a few 3D-toolkits for WPF. But for my masterthesis I built my own 3D-engine. It's almost complete but i would like to be able to draw the wireframes of my object (for example to show tessellation of a sphere). my engine can render almost every basic geometric form (cube, sphere, cone, cylinder, pyramid, ..)

have you any idea how to draw lines? (my only idea is to use a very thin cylinder or cube ... but i don't think that is very efficient because i have to render at least 8 points (12 triangles) for one single line)

Answer 1

因此，您只需将必要的数据以及颜色，多重采样，宽度或它可能需要的任何信息一起传递到引擎的像素着色器，然后使用PS画线。

Answer 2

If you are fine with unitary-width lines and you don't mind rendering wireframed then you can go that way.

A more complete alternative is drawing quadrangles composed by two adjacent triangles. You can use lines as primitives and take advantage of the geometry shader's capabilities and use it to generate the quad.

Create a geometry shader receiving the two points forming each line and outputting a triangle list. You just need to append four points to the output stream. Use the computations shown in this paper from NVIDIA, to calculate each of the four coordinates of the quad.

While the input of the geometry shader were lines, the output will be two triangles properly set up forming your line. Actually, this technique offers quite some flexibility since the quads are not constraint to being rectangles (ie each side can have different widths).