Problem with TG 0.9.43 render engine

[MacGyver]

Hello Folks,

with one special terrain I use, there's a problem when it comes to rendering. The attached image shows part of the image that I rendered. There's a line right through it, that I can only observe with that one special map. In this case it's diagonal; when I render the surface in an normal not-from-above-style, it's a vertical line, so at least it's a logically consistent error... Has anyone an idea what might have gone wrong and how I could get rid of that artifact?

Thanks in advance.

PS: If anyone is interested in the whole image I will photoshop it, so you'll see it without the line.

[Oshyan]

How did you create this terrain? Have you examined it in a heightfield editor such as World Machine, Leveller, Geocontrol, or Wilbur? Is there anything particularly different about it, or by "special" did you simply mean it is only this specific terrain that causes the problem?

- Oshyan

[gregsandor]

Is there any chance you have a stray white pixel at that position on the heightfield?

[MacGyver]

Hello, thank you for your fast reply! 

@Oshyan: I created it with Terragen 0.9 using the available options (Subdivide & Displace this kind of...). Yes, I meant only with this one specific terrain the problem exists. The only thing I can think of that is different is its size: I selected 4097 (the *.ter - File is 32 megabytes big). Should I resize it perhaps to a smaller size?

@gregsandor: I will include a screenshot of my heightfield in this post, I don't see anything special about this terrain.

[gregsandor]

Move your camera to the location of the spike and render it looks at about a 45 degree angle looking at the spike.  See if you can reproduce it.  A greyscale heightmap will be easier to spot it in than the multicolor one.

[MacGyver]

@gregsandor: Since I am not a native speaker I didn't understand what you wanted me to render but anyway, I put a greyscale image under this post. Perhaps you can try to explain to me again what I should try? Thank you for your effort, I feel really accomodated here 

[Oshyan]

Your heightfield looks to have a pretty extreme height scaling. If there is a small bit of lighter area it may be significantly exaggerated by this. If you could share the heightfield that would probably help diagnose, but it's likely to be the "single white pixel" problem Greg alluded to.

- Oshyan

[gregsandor]

Please attach the .ter to your next post.  I'll look at it.

What is your native language?

[MacGyver]

Here you go... BUT I had to resize the Terrain down from 4097 to thousand-something because it was still 20 megs big when I compressed it, so I couldn't post it here...
I speak german, normally

[MacGyver]

As I'm seeing right now while rendering with the decreased terrain size, the effect seems to be gone... perhaps because this "single pixel" that you spoke of was interpolated into nirvana when I changed the size...

For completion, the second *.rar Archive

[Oshyan]

I suggest making the full-size terrain available, perhaps using something like YouSendIt. But given that the problem went away when resizing, it is likely to be the single pixel error we have discussed. In that case you should try editing it in a good, dedicated heightfield modeler. If you don't own one, in order to work at full resolution you will probably have to use the free Wilbur, which is the only free heightfield modeler I know of that will work at those resolutions.

- Oshyan

[MacGyver]

Thank you a lot for your help, I'll try using Wilbur!