"Stair" artifact error while using Terrain Scene M

y721 · Post by **y721** » Thu Jan 20, 2005 11:47 am

It happens on those blocks close to camera. (higher detial LODs). It seems like the Some vertice with same height (y). But the correct display would be different heights.

Thank you for help.

steve

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The following is the config file setting.

DetailTile=3
PageSource=Heightmap
Heightmap.image=course1.raw

Heightmap.raw.size=1025
Heightmap.raw.bpp=2
Heightmap.flip=true

PageSize=1025

TileSize=65

MaxPixelError=10

PageWorldX=1025
PageWorldZ=1025
MaxHeight=500

MaxMipMapLevel=5

VertexNormals=yes

Post by **DWORD** » Thu Jan 20, 2005 1:16 pm

Is it the same problem discussed in this thread? If so, you can find the solution here.

y721 · Post by **y721** » Fri Jan 21, 2005 4:22 am

My problem is different. Some terrain blocks appear to be like "stairs" when the camera is closed.

My card is nVidia 6800 Ultra. I test with 5700. the problem remains.

steve

Post by **sinbad** » Fri Jan 21, 2005 6:17 pm

Chances are your data doesn't have enough precision in it. I see you're using RAW, which is correct, but maybe you converted it from an 8-bit source? 8-bit values can't handle large height ranges without significant aliasing. This will also make the LOD really crap because everything is far too jagged.

I've personally used 16-bit heightmaps with large ranges without any problems, but you _must_ make sure that your original data uses that range appropriately, and the transitions are gradual enough. 'Stairs' are caused by graduations in colour that are not smooth enough, exaggerated by scaling them because you're using too large a height. Your height is 50% of your height / width, which is excessive.

y721 · Post by **y721** » Mon Jan 24, 2005 5:16 am

I believe that my test raw file is 16 bits. I use photoshop with 16 bits. It displays correctly.

It might be the graduation is not enough. I will check the 'Leveller' setting to get better detail. Does any one recommend Terrain generation tool besides Leveller?

I believe that the max height setting is not related to width, right? As long as I provide enough graduations.

thank you, sinbad, I will try some more raw files.

Post by **sinbad** » Mon Jan 24, 2005 2:26 pm

I use Terragen personally, its 16-bit RAW output gives very good results.