texture distortion

Try changing the texture filtering mode to anisotropic or higher. I'm not sure what language you're using but here's the C++ and C# version.

pd3dDevice->SetSamplerState( 0, D3DSAMP_MAGFILTER, D3DTEXF_ANISOTROPIC );
pd3dDevice->SetSamplerState( 0, D3DSAMP_MINFILTER, D3DTEXF_ANISOTROPIC );

device.SamplerState[0].MagFilter = TextureFilter.Anisotropic;
device.SamplerState[0].MinFilter = TextureFilter.Anisotropic;

Hope that helps.

I'm not sure anisotropic filtering will have much benefit until you start rotating the textures around - from those screenshots they're screen-aligned?

I'd go after the texture coordinates myself. I've seen odd effects like you've shown (although with more regularity) when the texture coordinates are evenly slightly off-centre. Most pixels will get sampled correctly, but some will eventually get rounded incorrectly and the wrong pixel gets sampled...

If this is for screen-aligned rendering have you followed the rules shown in the "Directly mapping texels to pixels" article?

hth
Jack

It was a texture filtering problem. Setting to Liniar filtering or higher got the artifacts out. I thought the 9th and 10th parameters in texture-from-file function get you same result as SetSamplerState. So I haven't tried the SetSamplerState function.

Thanks for help!