Strange rendering with objects in motion

Unity Engine
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1

Hi everyone!

I’m becoming a bit mad with a strange behaviour that I cannot resolve.

I’m developing a 2D game for iphone and I realized that, when an object is falling due to the gravity, the rendering of the object is not “clean”. That means, the transition of the object between one frame and other seems not to be smooth. The framerate is correct (1800+ in editor, 150 in iphone) but is true that in iphone, the effect is more visible.

I thought that maybe could be an issue with the refresh of the screen, but I don’t know how to check it.

Here you have a little test with some primitives with rigidbodies falling and a orthographic camera to check what I’m talking about.

I hope you can help me with this issue because the game looks a bit ugly right now :S.

Thanks for all!

611162–21734–$test.unitypackage (8.25 KB)

2

Turn on interpolation for physics objects. Otherwise they only move during the physics update rate and not the screen update rate.

–Eric

3

Thanks Eric5h5 for your soon (instant? :P) answer.

When you say “turn on interpolation for physics objects” you mean put the field of rigidbody component “Interpolate” in “Interpolate” or “Extrapolate”, right? Because I’ve just tried and yes, the movement is better but not absolutely “smooth”.

It’s the best result I can get?

4

Yes, that’s what I mean. The iPhone screen is always vsynced, so it won’t update faster than 60fps. (Assuming you changed kFPS to 60 in the AppController.mm file, otherwise it’s 30fps by default). You could try changing the physics framerate to 60fps so it matches the screen update rate better. It’s .02 (50fps) by default. Of course that would be more CPU-intensive, so you could try 30fps instead.

–Eric

5

Make sure physics are performed in fixedupdate in addition.

6

Omg what a mistake! Absolutely true. Placing physics in FixedUpdate function plus interpolate mode on the objects resolve my problem.

Thanks for you help!

7

I’ve run into a troubling issue with Maya 2009’s Rasterized Rapid Motion. On our render farm running from the linux command line, Rapid Motion produces white dots and smears on the frames.

We have occasionally gotten this error to occur on our workstation computers as well, but mostly when running render.exe from the windows command line. Rendering inside Maya batch or the viewport does not (usually) produce this error. Obviously, the next test for us will be to try batch and viewport renders on the farm to compare, but with the holidays we are indisposed.

On the left is the error, the right side is rendered correctly.

http://img709.imageshack.us/img709/9800/example1.png
http://img709.imageshack.us/img709/4171/example2.png
http://img705.imageshack.us/img705/6694/example3.png

Note that in these examples, the file and the version of Maya are identical. The right side comes from the farm, the left side is from my laptop.

Here is what we currently know about this problem:

  1. It only occurs in the Rasterizer with rapid motion. Putting it on Scanline (standard “Production” Motion blur) fixes the problem, but results in far longer render times for a grainier blur.