Particles change Scale between Window and Render

Here’s a picture illustrating the problem I’m having:

In 2.56 I have an icosphere with a Hair Particle system, rendering a group of objects rather than strands.

However Blender’s display shows the particles slightly larger than they appear in the render. This makes it impossible to frame a ‘close-up’ on a particle.

Any ideas why they might appear a smaller size in the render?

I try it with a shot in the dark.

You might have encountered the infamous off-by-1 error in coding.
It might be that the render takes the particle data from a prior frame… hence off-by-1.

Could you check if frame 2 of your animation matches your render image?
If so, it most certainly is a bug and you should file a report.

After waking up today it came to me, that you´r having a hair particle system. It ain´t moving, so it renders my prior assumption pretty much useless.

I did some quick test. Same outcome. You are right.

In the viewport the groupobjects are shown with a bigger scale. It is not the hair lenght, the viewport perfectly matches the render for them. I am almost cartain it is a bug.

If anyone else wants to take a look or play around, here´s the blend.

Thanks for testing it. I’ve gone back to using a regular emitter, using ‘no physics’ and dead particles (like the old days!). That doesn’t have the same problem. ‘No physics’ doesn’t seem to create any (visible) particles using a hair system.

Any idea how I can submit a bug report?

http://www.blender.org/development/report-a-bug/

I´ll take care of it.

Fed in the tracker not even an hour ago, confirmed as bug, assigned and being worked on. Either compile a fresh svn once it is fixed or wait for 2.57a :slight_smile:

Thumbs up for the devs once more.

You can track the status here:
http://projects.blender.org/tracker/?func=detail&atid=498&aid=27008&group_id=9

It is fixed.