Proposal for Particle System

General Forums Blender and CG Discussions
21

Hi everyone,

Thanks to jahka’s work, now vehicles is represented in particles. I converted my vehicle trajectory data into the particle cache format. Blender load it much faster than bpy script and I can easily reposition all vehicles as a whole.

Still, there are some minor problem with regards to particle creation, I’m working on them.
http://i31.tinypic.com/vpgtvt.jpg
full size:http://i25.tinypic.com/2eb4x90.jpg

In the picture, the big box to the left is the object which particle system stick to, the empty object is used to reposition particles.

22

Hi everyone.

It’s been a while since I post last time. There’s days I’m busy doing my daily research and now I have free time again.

I managed translating the vehicle trajectory data into the external particle cache file format. Basicly it’s pretty straitforward, but it takes me some time to figure out how to convert the rotation into quaternion. Because I suppose the quaternion in x,y,z,w order but actually it’s in w,x,y,z order.

The particle setting is in the following pic. I give every particle a simple car model. It’s really simple, but still much better than a box in last version.:slight_smile:
http://i28.tinypic.com/1601xte.jpg

http://i30.tinypic.com/14w3aip.jpg
14w3aip.jpg724×451

http://i32.tinypic.com/2qi1jyf.jpg

When it comes to rendering I got a problem. Although the number of cars is not changing from previous object+ipo scene(2011 cars) but the rendering time becomes very long. Previously it’s about 30sec/frame, and now it’s 15min/frame! I found most of the render time is spend on the “filling orctree” phase, maybe it’s a bug of particle system/render system/both? Any one have an idea?

Anyhow, I managed render this frame.

http://i27.tinypic.com/122nbsw.jpg
122nbsw.jpg720×405

full size

I’v heard the durian project will use the particle system to simulate crowds, so I think there will be improvements in the following 3 aspects:

  • render speed
  • specify certain object for certain particle
  • animated objects for particle

In this week I plan to improve the scene by adding roads and buildings and trees. The first thing I want to do is creating a texture for the ground with roads on it , but how can I align the roads on the texture with cars? any tips?

Edit: I try to render an animation in spite of the really slow speed but blender(2.5 svn 20180) crashes after 31 frame.