[SOLVED] Problem with heightmap generation using terrain_x64.exe

[ashwin.sudhir]

We use terrain_x64 to generate heightmaps from meshes.

If we have intersecting surfaces on the terrain mesh, we get non-deterministic output. Sometimes the heightmap contains the upper point, and sometimes the lower point.

This causes our models to go beneath the terrain if a lower point is selected.

Note : We also tried merging all surfaces into one surface before generating the heightmap.

 

Here is an image our artists thought might help

 

 

Also, on a related note, is there any way of editing the R16 images generated by terrain_x64.exe in Photoshop? Our artists have been hunting for a plugin that can load R16 images for a long time.

 

Thanks.

[unclebob]

Hi,

 

That seems strange. Terrain tool clamps z values from 0 to 65535, but before clamping it will resize to your mesh to (terrain_width, terrain_height, 65535) size.

 

Could you provide this mesh?

 

Also, you can convert R16 texture to full RGBA texture then edit it in Photoshop and convert back using usc and Image class.

[ashwin.sudhir]

Hi unclebob,

 

The problem is not with the XY dimensions of the heightmap, it is with the Z dimension.

If there are two vertices with the same XY coordinate and different Z coordinates, how does the heighmap tool resolve this? This was the essence of my question.

Is this method of resolution not deterministic?

 

About the other question, converting R16 to RGBA8 - will this not cause loss of precision? If I am imagining it right, RGBA8 wil have all the R16 values lowered to an R8 channel. I don't think that would be a good idea. Or is there something that I'm missing here?

 

Thanks.

[unclebob]

Hi Ashwin,

 

Thanks for your use case. :)

 

You're right, it's undefined behavior because of division by zero error. The problem is that we can't render 'vertical oriented' triangles from top-down view properly in this case. By 'vertical oriented' I mean triangles with same x or y coorinate for all vertices. I think we probably should skip that triangles.

[ashwin.sudhir]

Thank You unclebob!

Our artists are blocked because of this, could you suggest a workaround for this for now? And any idea when we can expect a fix for this?

And also, could you address our concerns about loss of precision when converting R16 to RGBA8, editing and converting back to R16?

[unclebob]

Hey Ashwin,

 

We'll fix this issue ASAP.

 

Also, you can save your r16 image as png or psd (just pass proper extension to terrainmesh -o flag) and simply edit it in photoshop. No plugins required.