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FSX errors-- not creating a .BGL

I am hoping Arno or someone can translate what these errors mean. I have divided my gates into smaller files, but that doesnt seem to be helping. the last time i ran this particular model there were 12+ gates and the model compliled fine. I went in to move the gates into more correct positions and when i tried to use MCX it would not create the .BGL

heres the ss of the error.


In FSX you cannot have more than 65535 vertices that use the same material. Try creating a copy of your existing material (that covers most of your parts) and make a tiny change to it. Then apply that material to some of the parts using the original material.

Hope this helps,


Staff member
FSDevConf team
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How many triangles does your model have?

MCX should automatically take care of the 65k limit. It will make small changes to the material. But it's not 100% fail safe.
here are the attributes. like i was saying, it did go through once, but after making a few small changes, it wouldnt work again. o_O:(:confused:


I even tried to break the model down into separate gates and do them one at a time, and STILL wouldnt work!

I cannot see from the small 3D model image size in the OP screenshot whether it had yet been mapped with custom texture materials. :scratchch

It is IMHO, important to remember that by default Sketchup applies a "White" texture material on all Front / exterior (sur)faces, and a light "Blue-Gray" texture to all Reverse / interior (sur)faces of a 3D model which has not yet been mapped with custom texture materials. ;)

Therefore, MCX will likely infer that there has been more than 65k vertices mapped to an individual texture material when it first imports a Sketchup 3D model that has not yet been mapped with custom texture materials and/or multiple "unique" copies of the default "face" texture materials.

FYI: One can select and right-click (1) face on a wall, then choose "Make Unique", then reselect that same face and all other coplanar (and non-transparent) faces on that same wall, then right-click, and choose "Combine Textures" ...to make a 1-piece texture material for that wall, which helps solve some of the per-texture material vertex mapping limit issues, while also reducing draw calls. :idea:

Hope this helps ! :)

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Staff member
FSDevConf team
Resource contributor
Can you show the statistics in MCX? Because SketchUp counts faces not triangles, so it's hard to see how many there are.
As Arno informed, SU counts only faces. If every single face on your model is a simple rectangle, the object would have 304,116 triangles. In truth, any number of your faces could already be triangles, however be aware that faces are not limited to 4 sides. In actual practice, I have found the number of triangles in my models to be 3x or 4x the number of faces. The simulator has a very specific limit on the number of triangles it will compile and a very practical limit on the number of times you can change materials to exceed the 65k barrier.
This is a fairly drawn out way of suggesting your model has more geometric detail than the simulator can comfortably handle, that you could efficiently replace with graphical detail. Graphical detail is the idea of covering your model with a photographic type representation of it, as opposed to individually coloring each face. Consider how two transparent rectangular images of a tree, placed at right angles on the vertical axis, comprise a pretty decent graphical representation of a tree. All those branches get rendered with 4 triangles.
Gary's suggestion for counting faces is completely valid; however, may I suggest that even half of 150k, for a single jetway, is still far beyond the actual and practical limits, when it is combines as a sub-model into a much larger representation of a terminal? You would want to consider that the majority of rendering power should be reserved for the user aircraft to prevent stuttering and freezes and modern payware aircraft, with their curvy hulls and fantastic details, require a lot.

I like to think of efficient modelling as digital origami, because with origami, you get fantastic detail from a single piece of paper. Your modelling appears to be excellent and I'm sure you put great effort into it. If you decide to create a simple version, this will be quite useful. You can color it and capture screen images of it to project onto your simpler geometry. You can get a rendering extension that will add shadows and depth, record a screen image and project that onto your simpler model.
While I was traveling and away from a 'real' computer with Sketchup installed (was using an I-Pad), I had forgotten that in the Safari web browser, I could have copied and posted some relevant info from one of my earlier posts here at FSDeveloper, which further documented intermediate steps involved in use of the "Combine Textures" feature.

The potential to 'reduce draw calls' by using the "Combine Textures" feature in Sketchup as I alluded to above, should be more apparent as one reviews the following quoted excerpt:


In Sketchup, you can texture the entire wall (either as one single section, or as multiple textured sub-sections or "faces"), and the door ...in any order that you wish.

When you are ready to 'combine' the various faces which make up the wall surface, (assuming they are all exactly in the same 3D plane of the wall or "coplanar"), choose one of the faces with a single left mouse click so that it has the blue dot pattern' indicating that it is "selected", then right click and choose "Make Unique Texture" from the pop-up context menu.

Next, while holding down the < CTRL > key on your keyboard, single left mouse click on each of the faces that you want to combine into one texture so that they all have the 'blue dot pattern' indicating that they are "selected".

Now, release the < Ctrl > key, and right-click on one of the selected faces, then choose "Combine Textures" from the pop-up context menu.

Sketch up will pop up a prompt: "Do you want to erase interior edges ?"; choose [Yes].

You now have a one-piece texture for the entire wall surface.
Most structures one makes in Sketchup for FS are likely "flat" walls with a number of co-planar faces 'textured' with numerous "Materials".

Consequently, unless each such Material requires unique render settings in the ex: MCX Material Editor, one should be able to reduce 3D model geometry complexity fairly easily by use of the "Combine Textures" feature (while also allowing erasure of interior 'Edges', so that faces are merged into the 1-piece wall Material ...with locally-mapped texels already in position within the overall texture image of the wall). :pushpin:

This also ensures that the pixel size is uniform across the surface of the wall, which is yet another less often discussed aspect of performance hit encountered when the FS rendering engine has to deal with mis-matches of pixel size in physically adjacent texels mapped within the same Z-order drawing distance from the user aircraft camera position. ;)

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