Rendering Times

Hi - I’m new to this place so please forgive me if I seem a bit niave. But I’ve been using Blender (ver2.37a) for quite a while now but one thing always bugs me. :<

When I render an animation, one particular frame takes about 5 mins, yet the one directly afterwards takes twice as long! What’s going wrong? :frowning:

I know that the number of vertices in a particular frame affect the rendering time, and I am oversampling (5) and ray-tracing (64). To cut down on rendering times I’ve also implemented Y&X part renders (both at 3 so that the frame renders in 9 seperate parts) and that’s had limited success cutting down the rendering times. But as far as I know there should be no logical reason for this to happen. And I don’t think it’s my hard-ware (Pentium II [1.3GHz] 128MB RAM) as I know it’s pretty primitive by today’s standards.

So is there anyone that can help? I’ve resorted to let my computer run over-night! :expressionless:

Did you try 128/256 octree resolution? I am not sure, because I dont know how much stuff you got in the scene.

I’m using the lowest resolution (octee 64), and there are only three renderable objects in the scene. A plane to act as the ground, a city section model, and a medium res. F15. It does add up to lots of vertices but it doesn’t explain the erratic rendering times…

check if your computer is not starting to swap data from the hard drive, beacuose you have very little ram, and it may acour, that the first frame fits in memory, and the second has to be swaped from the hard drive.

Agreed… Blender LOVES lots of RAM. 128 MB is not very much for rendering at all. I have 512 and most of the even that isn’t enough. My girlfriend has four times as much and it does in fact render MORE than four times faster.

Agreed. . . the three biggest factors in render times are

  1. Processor speed
  2. RAM
  3. Scene complexity

The more processor speed and the more RAM, the faster you renders are going to be.

But, how fast it exactly renders depends on how complex the scene is. In the first month that I used blender I noticed that no matter what kind of machine you have, it will eventually run slow. I bogged my self down with a 17 hour render (just one frame) on my AMD Athlon XP 2800+ w/ 512MB of RAM. This is where you have to watch how many effects you use. I had full raytracing, raymir depth=10, raytransp depth=10, etc.

Ambient Occlusion will inflate render times too.

Are you running the intle optimized version. That’ll give 40-50% render speed in most cases.

That’s normal for doing an animation. That’s what I do too. A short 10 second animation for example, is equivalent to 300 single renders. Even if your individual frames render in 30 seconds each, that’s over 2 hours you have to wait (16 hours if you have motion blur on). I’d rather be asleep.

Professional animators leave their machines running over the weekend. That’s why they sometimes get odd results, which they sometimes put onto DVDs. The Shrek one has an animation of the donkey with the hair too long so that he just looked like a giant furball.

Phew! Thanks for clearing that up! :smiley:

And you guessed right, I am using my hard drive as a paging file. Well that’s a load off my mind - and hopefully, I’ll get a new laptop so that I’ll be able to have faster renders…thanks!