exporting 3ds or similar of a big mesh

[creat326]

Hi

I want to generate a huge terrain, and I love the fact that you can title the terrain bitmaps and it will save seperate files.

My question is, is there a way to split the mesh so that each image match that mesh? I want to generate 64 meshes: 8x8 'quads'
since the terrain is huge, i guess i need to split the texture into decent sizes but i don't see an option to split the mesh

[Aaron]

Hi Creat326,

Currently the mesh optimiser does not support splitting meshes into tiles. Thanks for the suggestion; I've now added this to the development plan, but I cannot offer an ETA at this time.

Best regards,
Aaron.

[creat326]

hi
was this ever done? O:)

[Aaron]

Hi Creat326,

Sorry, I've not yet had time to have another look at the mesh decimator. Alas, I still do not have an ETA for this feature; the dev plan is quite busy at the moment.

If you can survive without using a decimated mesh, you can export the full-res heightfield mesh as a tiled set of OBJ files. To do this, select the 'File->Export->Export map layer' menu option, select the 'heightfield' option, then in the export wizard enable the 'split map into tiles (mosaic map)' checkbox, set the filename of the mosaic file, click 'next >>' to proceed to the second wizard pane, set the file format to OBJ, set the tile size to suit, and press OK. This will then export the whole heightfield in a set of wavefront OBJ mesh files at full-resolution, which will obviously contain many million triangles. This may or may not suit your workflow, as I'm guessing you'll still need to individually decimate the mesh tiles before use.

Best regards,
Aaron.

[creat326]

it actually works fine with the .obj since I can import it to 3ds or whatever and paste the tiled textures on it.

only one feature is missing... the mesh optimization present in the simple "export to obj" option. It doesn't work with tiled terrains in here.
If you could incorporate that optimization that limits the triangle counts into the resulting .obj while keeping the tile borders conected (so that they don't generate empty spaces later on when put together) it would rock.

[Aaron]

Hi Creat326,

I've implemented a tiled mesh exporter in the latest build, which can export seamlessly tiled terrains in OBJ, 3DS or X formats, along with their textures &c. For more info, please see this blog post. Please let me know if you find any problems with it.

Cheers,
Aaron.

[creat326]

Aaron, thanks for the reply. Why the unoptimized edges though? Any particular reason?

The way I was solving it before you released this update was to put the whole mesh into another software. Optimize the whole mesh and then splice them on quads. It works just fine and it's the technique I've used for my dogfight game: www.dogfightplay.com

I guess you don't want to lose quality on the edges since they wouldn't match. But why not lower the quality before the split happens? Otherwise you get funny results: mid quad with low poly and quality and borders with crazy amount of quality and poly.

[Aaron]

Hi Creat326,

I agree that using unoptimised triangles at tile edges is not the best way to ensuring consistency across tile edges; it was however the easiest to implement. The longer-term plan is to optimise the mesh before tile splitting, as you suggest, but this is more difficult to do properly. In particular, the exporter has to support maps that are too large to fit into RAM (billions of raw triangles, etc.), so it can't simply load the whole terrain mesh and optimise it before cutting the tiles. Instead, it will first have to cut the raw terrain into tiles with a reasonably-large overlap boundary that duplicates some data from neighbouring tiles. These tiles can then be optimised, and the unneeded overlap can be trimmed off before saving each tile. Some triangles will span across these boundaries (especially since arbitrary tile sizes are permitted), so the exporter will also have to slice some triangles in two or three when cutting the tiles; something it doesn't have to do presently. None of this is outrageously hard to do; it's just harder than splitting the terrain first and using unoptimised triangles at the edges, so I thought I'd try that first and improve upon it later.

Cheers,
Aaron.

[Aaron]

Hi Creat326,

I've updated the mesh optimiser plugin to optimise tile edges, so long as the tile size is a multiple of 64 (more info + pics here). The updated plugin is included in L3DT 13.10 build 0, which is on the downloads page now. Please let me know if you find any problems.

Best regards,
Aaron.