forum.heli-x.info

Hello! First post!

I recently got heli-x and I have been loving flying FPV in the underground garage with the H.250 (https://www.youtube.com/watch?v=kpI-KsrTg0k)

It would be great to have more locations to fly around in. Is there a guide or documentation on creating 3D airports?

I have a background in video game development and I would love to take a shot at making some locations.

So I thought I would ask here before I wasted too much time trying to reverse engineer all the OBJs and XML files myself.

Thanks!

Hi

Awesome flying skills with that H.250 mosquito! and a cool movie!

I don't think there is a creation guide for 3D airports. But I can give you some starting points. With your background in video game development it should be easy (even I found it out... glad you liked the garage )

- The name of the folder is the name of the airport. No subfolders allowed.
- the .XML file with the same name as the airport controls all the objects in the scene, their type, position etc.
- The objects are then in Wavefront .OBJ format (I made all with Blender and exported them) with the texture/color information to each in the according .MTL file.
- Exporting to OBJ you should triangulate all faces, write the mtl file, ignore edges and points not associated to a face.
- I found it easiest to model all objects in one scene together, then exporting one of each kind with the object origin set to the desired position (because as explained below).
- To make a good scene you should/can keep an eye on this (as you certainly know from game design):
* Keep Vertex/poly count low!!
* Keep texture images low in number and filesizes.
* If using many instances of the same object (e.g. columns in the garage), you can position each and group them together in a separate combined .xml (e.g. Acolumns.xml) ...this .xml can then be referenced in the main .xml as if it was a single object. If you would export each as individual OBJ or as one big merged, calculation load will get much higher and framerates drop considerably.
* When only using one instance of an object, it's easiest to set its origin to the global coordinate center before exporting (positioning in xml then is simply at 0,0,0). If you want to multiply it in the XML, be mindful of where to set the origin before exporting (e.g. on the column base center) for easier positioning later on.

- It may be easiest for size comparison if you start with a copy of an existing one and reduce it to the ground plane at first - then build up on that, object by object. Keep it simple at first until you know how to get it working. you can then easily add more objects later on.

Good luck and have fun!

Btw, If you like FPVing - there is also an awesome 3D scenery of a canyon somewhere in a thread here.

Thanks, that will give me a good head start! I was starting to figure some of that out by taking apart your garage

I couldn't find in the heli-x documentation; what is the coordinate system based on? meters? or is it an arbitrary unit? How do I figure out the translation coordinates for repeated objects in the XML, like the columns? (without punching in random numbers and then iterating on that until its in the right spot)

I did see that canyon scene, I don't find it much fun to fly in, only because the H250 model seems to glitch out at higher speeds caused by such an open space.

kfhammond wrote:I couldn't find in the heli-x documentation; what is the coordinate system based on? meters? or is it an arbitrary unit?

Afaik it is just the units passed on when exporting the OBJ - so usually the base units as in your 3D program. However, Heli-X is considering 1 unit = 1 meter, but not 100% sure about that. That would however correspond with the helicopter sizes.

kfhammond wrote: How do I figure out the translation coordinates for repeated objects in the XML, like the columns? (without punching in random numbers and then iterating on that until its in the right spot)

1st move your object to the coordinate origin before exporting. Like that it would be centered too in Heli-X when put at 0,0,0.
Then, as the units are the ones from your 3D program, you can read them out from your scene there. Check the coordinate orientations too. In my Blender coordinates are X/Y/Z by default, while in the XML it is X/Z/Y (with Z is up in both). ...So a column at 0,0,0 in Blender would be at 0,0,0 in the XML, a column at 2,4,6 in Blender would be at 2,6,4 in the XML,...and so on.

What is the advantage of placing multiple instances of an object using translation in the XML, versus having a single object containing the copies?

Many distinct objects make the collision detection faster.

Michael