Renders not completing.

Started by Captain Teebs, May 13, 2020, 07:29:17 AM

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Captain Teebs

I've been using Terragen 3 for a number of years and have happily made thousands of images, mostly using real-world elevation data from Scotland and Cumbria. Just lately though I've hit a mysterious problem that has scuppered my projects. My renders are now failing to complete. The clock is still ticking, it hasn't crashed, but when it comes to the foreground I am left with large areas blocked out in black which make no progress. The top of the render, the background is fine but somehow Terragen cannot compute the extreme foreground. I always run a tiny thumbnail test-render, 150 pixels wide and this works fine and completes. When I increase the scale this problem occurs. I've tried cropping a region of foreground and just rendering that but still it does not compute. I must have changed a setting somewhere but what could it be? I've run out of ideas.

Thanks in advance for your attention and any suggestions.


Hi, welcome to the forum.

There is a known bug where images around 20k by 15k or larger will fail to complete. But from your description it sounds like something different is happening.

- What resolution are you rendering at?
- Is this Terragen 3? Which version exactly?
- How many threads are you rendering with?

If you can share the project file with us we might be able to see where the problem is, or investigate further to find the cause. If you don't want to post it here you can send a message to
Just because milk is white doesn't mean that clouds are made of milk.


A side question: what sort of resolution data do you have for Cumbria? I used to live in Keswick.
Just because milk is white doesn't mean that clouds are made of milk.

Captain Teebs

Thanks very much for the prompt response Matt.
I am using Terragen 3 64bit build
Rendering at a modest 1400x1100, maximum threads 64 but even at this 400x267 resolution the render fails. See attached image.
However when I pull the camera back so that the foreground is not in such close proximity the render works fine. This seems to be the key factor.
I am happy to send the tgd file by email if it can't easily be resolved.

On your other question; Keswick is a beautiful place, you were lucky to have the opportunity to live there. How could you leave!?
I've been using data from . I think it's at 3 arc second resolution, so not ideal. I have a fledgling project using LIDAR data, much better but such tiny terrain tiles that need stitching together and everything needs re-scaling, I've shelved it for now.


The first thing I'd suggest is updating to 3.4. Lots of bugs would have been found and fixed between 3.1 and 3.4. You should be able to use Check for Updates in the menus.

How many cores does it show on the splash screen (or About box)? Maybe you are using 64 but I am guessing 64 is just the maximum setting in the render node, not what it's actually rendering with.

If the splash screen shows more than 32 cores I would recommend overriding this in Preferences so it's no more than 32. Actually I recommend overriding it on any computer to set to be a little bit less than what's detected (e.g. if 8 are detected, set it to 7, and if 32 are detected, set it to 28). This makes the UI and system more responsive while rendering.
Just because milk is white doesn't mean that clouds are made of milk.