The most important condition is :
get the approval from original maker of the track.
First, more often than you think, people are actually very nice, and they might give you the permission to use their track.
Second, this shows respect for one's work; the same respect that you would like to see for your work as well, when you will finish something.
And third, if I may add, I think we need to restore the "faith" in the modding scene; when you see so many rips and illegal conversions invading the net everywhere, it's not a good image to the game itself, but most importantly it makes it very hard to motivate new (and maybe very talented people) to join in.. and without these artists with big heart and big skills it will be hard to see new "gems" in the sim-racing world.
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Having said all that, I hope you have the permission to convert the track you are looking at, so let's get started.
When doing a track from scratch, you usually choose your preferred 3D package and use it to build your project. When doing a conversion, it's not so much different: you still need the track in an editable 3d format, but instead of creating it step by step you convert it from whatever the source format is, to something you can work on.
In your case, if you are talking about Race07 and rFactor, so one good tool is as mentioned
3DsimED. Before going any further, you also need to decide what 3d editing software you'll use (Blender, 3dsmax, Maya, etc), so that you can decide the format you'll save your track as.
After that, the basic steps are :
- import your track into 3DsimED
- save the textures to the 'texture' folder
- export to your preferred 3d format
- import/open it in the 3d editing program
- follow the
guide.
, not black and white to do. I hope that what you ment to say. or I don't understand.