The Populator

[choronr]

The issue is the populator. My entire scene is almost complete with populations of vegetation. Now, I want to tweak some surface setting and make a cropped, test render to see how the tweaking works out. Each time I do this, the populator starts running again and eats up a lot of time. Is this normal?

[Oshyan]

Adjusting certain settings will cause the populator to repopulate and this is unavoidable. But do make sure that you have "recompute every frame" unchecked in your populations.

- Oshyan

[choronr]

Thanks Oshyan; I'll check that. One of the two populations on the scene takes quite awhile to populate. I guess I could disable the pops while tweaking other settings.

[bigben]

If you connect the last shader to the populations terrain input you may find that any change to the surfacing will result in a repopulation. You might be able to cut this down by connecting only the last node with any significant displacement (or the compute terrain node)... but I havent tested this. You can always cancel the populator and the render will continue with only the objects that have been "populated".

On a slightly related topic... if you use a distance shader to restrict the extent of a population from the camera, it pays to set the population size/position so that you have as little "empty" population as possible. The speed of the populator seems to be largely related to area, so a large area of a population with no objects in it will add a substantial amount to the render time. The other situation people commonly use is a through camera image map. In this case there's no point placing the camera in the centre of a population as everything behind the camera won't be visible but will be calculated.  This is a particular performance consideration for animations, where it pays to move the populations with the camera.

[choronr]

Thank you Ben. Sorry I haven't replied sooner; but, I am traveling and haven't had a chance to catch up. As soon as I get back, I will go into your response in depth and get back to you.