Spheres and columns taking up excessive memory

[krogerfoot]

When exporting Blender files with Xplane2blender, I find that models with spheres and columns end up being comparatively huge. What I thought was a simple patio with 20-something posts and globe-shaped lights turns out to be tens of MB in size, making it impossible to import into SketchUp for relatively painless lighting. 

 

Is there a secret that I'm missing with regard to exporting obj files from Blender? How do modelers make objects with spherical elements that don't end up eating up huge amounts of memory?

[Colin S]

The issue with anything rounded in X-Plane is the number of triangles. If you have a cylinder with, say, 50 sides to simulate roundness, that is 100 triangles. 20 of those would result in an extra 2000 triangles - and that's just in your scenery. Spheres are hell when it comes to rendering, probably upwards of 3000 triangles in one sphere, although I've never even bothered trying to make a sphere for this reason. I usually make use of 6 or 8 sided cylinders when modelling for X-Plane, and I would just altogether avoid spheres.

 

Hope this might have helped. As for memory, every node and vertex requires another line in a 3D file, so add 5000 triangles you've got 5000 more lines, boosting volume. Basically, (and this is just my opinion), rounded things should be reserved for things like aircraft and fuel tanks, that the users will really be focusing on. Make use of texturing to compensate for the crappy appearance of an 8-sided column.

[krogerfoot]

Thanks for that insight. The columns for my model definitely could stand to be a lot simpler—I'll try that. Still, I feel like I see spherical elements in aircraft models all the time, so I wonder how those are achieved.

 

I've really gone overboard on what is, in the end, a fairly trivial component in this scenery, and hardly visible in the finished product. I discovered how huge the file sizes had become when I was unable to import it into SketchUp to do the lights, which are going to be a big headache to code into the OBJ files.

 

Thanks again for your help.

[Colin S]

No problem; Glad to be of help For less important aspects of scenery, I generally try to leave extreme detail to the texturing.

[ilias.tselios]

At blender Scene menu/X-Plane there is an optimize check box. It optimizes the mesh for exporting, though it take more time to export.

 

Use the less vertices as possible. I.e. a column (cylinder) should be more than ok with 12 faces (even less). About the same for spheres. For curve surfaces always use smooth shading in blender. That passes to X-Plane as well.

 

Another thing is to delete faces that will not so up. Like the cylinder should be open on top and bottom since the one will be inside the ground and the other inside the sphere (if I have correctly understand what you are trying to do). 

[krogerfoot]

Thanks very much for the advice, fellas. I'm beginning to realize the importance of planning ahead when modeling in order to save lots of time texturing and to minimize complexity. I will also try the smooth shading.