Saturday, 25 October 2008

Clipping in Away3d

As promised I've conducted a series of experiments to try and understand the differences between the various 3d engines for flash. Since I lack the time to learn and produce a movie using each api, i have concentrated on Away3d and Sandy. A study of all 4 of the engines I have previously mentioned can be found here.

Since discussing some of the drawbacks of Away3d and clipping problems, I have researched methods to solve this issue. As suggested by Peter Kapelyan one of the easiest methods to correct clipping in Away3d or Papervision is to simply add extra triangles. Since the problem occurs when part of a face extends past the camera, this is an obvious solution, thus creating a smaller section to be culled.

The following examples show a plane created with Away3d. Creating a plane with 3x3 segments results in extreme clipping and really is a problem. Upon increasing to 4x4 the problem is immediately less obvious; 5x5 segments completely irradiates the problem. Of course increasing the number of faces is going require more processing power and memory usage and is ultimately less efficient. It it is important to take this in perspective; as far as I am aware Away3d is quite a fast 3d engine. Sandy suffers from clipping as much as Away3d when segments are reduced to two. Essentially you must nearly double the number of faces used if converting from Sandy to Away3d (3 -5 segments). This is a primitive study and does not give indication of scalability; hence there is the possibility that differences between the two engines could become more or less exaggerated with complex scenes.

please be patient waiting for these to load they are loading from a very slow server 0_o
use keypad up and down to move along the plane

Away 3d 3x3 segments

Away 3d 4x4 segments

Away 3d 5x5 segments

Sandy 3x3 segments

Some interesting blogs regarding first impressions on a variety of 3d engines and workarounds for issues such as clipping. coobico, saumyaray, Ian Lobb.


goooooood girl said...

your blog is very good......

C├ęsar said...

Hello Electrobunny,

So is there a solution to improve this clipping in Away 3D ?