Instant Terra Forum

Instant Terra => Crash and bug reports => Topic started by: S-ed on December 25, 2017, 03:52:06 PM

Title: Erosion bug (evaporation/time)
Post by: S-ed on December 25, 2017, 03:52:06 PM
On certain advanced settings of Erosion, Instant Terra may lose the landscape permanently.

To reproduce:

Here's link to imgur:

p.s.: fix your attachments, seems it's impossible to attach animated GIF files

Title: Re: Erosion bug (evaporation/time)
Post by: Alexis Vaisse on December 25, 2017, 09:45:19 PM
Thanks a lot for your feedback.

The Advanced settings of the erosion simulation node provide you direct access to the low level parameters of the simulation.
They are not clamped, meaning that you get maximum freedom to test various combinations.
The downside is you can very easily make the simulation diverge, more or less rapidly.

This is what happens in your video: the time step becomes too high and the simulation diverges extremely quickly: on one frame you can see some spikes and on the next frames the terrain starts to be eaten. In fact the heights values become very high or very low and can reach +infinity or -infinity, making the terrain invisible.

We are currently working on the erosion simulation. We don't know yet if we will keep the Advanced settings. If we keep them, at least we will reduce the range of certain parameters to minimize the number of cases where the simulation diverges. We could lower the range enough so that the simulation would never diverge, but that would reduce the liberty of the user to try potentially interesting combinations, so that's not an easy decision to take.
Title: Re: Erosion bug (evaporation/time)
Post by: S-ed on December 25, 2017, 10:35:32 PM
The issue not in the simulation. It's afterwards.
Read #4.
If you rotate window when landscape is missing - it will disappear permanently.
Title: Re: Erosion bug (evaporation/time)
Post by: Marianne Calva on December 26, 2017, 08:34:49 AM
We'll check this one, thanks for reporting.