V4 populator cache.

Started by paq, July 25, 2013, 09:40:43 pm

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July 25, 2013, 09:40:43 pm Last Edit: July 25, 2013, 09:45:26 pm by paq

First thanks a lot for the new multi-threaded populator, the difference is really huge.

I just wondering if something can be done when you are populating a very large terrain, lets say 8*8 km.

If I undestand right, terragen is populating the terrain into 2 steps :

1)  sampling the terrain accroding to the populator settings (spacing, orientation)
2)  Reading the density shader to decide if instances are visible or not.

Am I right ?

If yes, it would be really helpfull if we could tweak the density shader without loosing the saved cache.
For the moment we have to hit the populate button if we want to see any change made is the density change, meaning that cache is lost. Despite the mutli-threading, sampling a large terrain with a really smal spacing can still be huge process.

In other word it would be handy if the 'populate now' can still read the cache (actually populate now will turn off instance caching), and only update the visibilty of the instances according to the change made in the density shader.

I'm not sure I'm very clear here :)

It would save a lot of time, especially when you want to mix different grass patches for example, because they can all share the same position/orientation cache. Only density will change.



Hi paq,

First off I should say there is a bug with the instance caching with populations over a certain size (4,000,000 instances). However it is fixed and will be in the very next release. We've also made it much faster at writing cache files and more efficient with memory.

To address what you're saying, the cache is really intended to be something for once you've finalised the population. We could look at something like you suggest down the track though.




Hi Joe, that's good to know about the bug !

Thanks for listening :)