[Personal] - HD Rendering Problem

It was recommended to render our final animation in HD, however I came across an annoying problem when I did. Every few frames, the heads of the audience group underneath the left tent randomly extends to the top of the scene. I have no idea why it does this, as when I render the animation in a lower quality, the heads dont extend.

It could simply be because in a lower quality, the extended heads are just not visible. However , the lower quality renders were only in a slightly lower quality compared to the HD render, so you would think that they would still be visible. I believe that it could be to do with the method of rendering.

As rendering in HD takes such a long time, I had to use another method rather than simply rendering the whole animation on one computer. I had to do a net render, where by I used several computers at once to render each frame individually as a bitmap. This method dramatically reduced the rendering time. I believe that as it rendered it as bitmaps rather than an avi file, it showed these stray extended pixels. This is why they did not show up on my lower quality renders as they were rendered as an avi file.

Unfortunately, at the time of writing this, we have to present out animation to our client tomorrow morning. I just dont have the time to re-render the entire scene, so they will have to annoyingly stay. Luckily, they are not that noticable, so hopefully they wont draw the attanetion away from the lawn mower racing.