.3dp vertex manipulation: any good apps?

[Gumboots]

Howdy folks. Got a question for you.

I'm one of the few remaining nutters who still plays Railroad Tycoon 3 sometimes. Yes, they do exist (mostly in nice little padded cells). So, being nutters, every so often one of us gets the idea to customise some models. Problem is that these are coded in .3dp format.

Someone found an app called 3D Object Converter, which lets us see the wirefame but doesn't seem to let us do anything with it. I wouldn't mind paying the maker his asking price if it'll do what I need it to do, but I'd like to be sure it will do what I need it to do before I lay out any cash. Is anyone here familiar with this app?

What I need is for his paid version to either be capable of directly manipulating the vertices (IOW, act like any CAD app) or at the very least, be capable of exporting the .3dp to something else that will let me play with it, and be capable of feeding the results back into a game file that RRT3 can use without frying my box.

Anyone got any suggestions? Kthnx.

[shakotay2]

Is anyone here familiar with this app?

Not me. But from the Formats tab in the link you can see that saving of geometry and texture uvs seems not to be supported for Railroad Tyccon 3 3DP format.

[Gumboots]

Well it says it can load and save the geometry, just not any of the textures stuff. That's ok, becuse it's not hard to work around that with standard gfx apps (I already know how the image mapping is done). The really tedious bit at the moment is manipulation of vertices and normals. If that can be sorted it would make a big difference.

[shakotay2]

Well it says it can load and save the geometry, [...]

Where did you get this info from?

[Gumboots]

Formats page on his site. I'm not sure why the page you found mentions geometry for .pk4, since .pk4 isn't really anything to do with geometry. It's really just a basic zip.

[Gumboots]

K, have a bit of an update here. It turns out that the .3dp used in RRT3 is not really a .3dp. It seems to be a mutant in-house variety of .3ds, with a different file header and maybe a couple of other minor changes. This may explain why 3D Object Converter claims on one page to handle .3dp, but on another page claims it doesn't edit the RRT3 version of .3dp.

I tried using the free version of 3D Object Converter to export an opened RRT3 .3dp as .3ds. The process completed, but the resulting file only had around one third the byte count of the original, and appears to be useless.

However, it seems (according to some work someone else did) that it is possible to take the hex from a geunine .3ds and paste it into an RRT3 .3dp in a suitable hex editor, and the resulting file will work in the game. This opens up the possibility of designing models in any CAD app, and either exporting straight to .3ds (if it will do that) or using a converter to convert a .dxf to .3ds (there seem to be plenty of converters around for that). The resulting hex from the .3ds could then be used in the game's mutant .3dp, with a bit of luck.