Antialiasing

Images rendered from a 3D package can display ugly aliasing artifacts. These occur at the edges of objects. When rendering an image, the fastest way to do so is to take just one sample per pixel. On edges this sample can either hit the object or miss is, resulting in jagged edges

Increasing the amount of samples will smooth out these edges: the aliasing artifacts are reduced.

Antialiasing in LightWave

The amount of anti-aliasing used when rendering an image is determined by the setting in the Filtering tab of the Render Globals, which can be found under Render tab → Options, in Layout of course since this is the program we render from.

The Anti Aliasing option is set to none by default, which is fine for test renders. Increasing the amount of passes (the number of times pixels get sampled) will result in a smoother image.

In case you are wondering what PLD stands for, here's a quote from the LightWave Manual:

"NewTek has introduced a new technology to allow significant improvements to Antialiasing called "PLD antialiasing" (Pixel Lattice Deformation.) The technology allows rendering to be undertaken with a much smaller number of passes, but without sacrificing quality."

I advice to just use the new PLD anti aliasing and not bother with the classic stuff

The Reconstruction Filter determines how the samples that are taken for each pixel are combined, different filters create softer or more harsh edges