Scrambled mesh

Hello Community!

A few words about me and why I am here:
The possibilities of VR got me to Unreal and, stumbling yet learning, I managed to get the build-chain to work for x86 and Android.
My ultimate goal is the recreation of real places into VR scenery. A year ago I began with a 3D printer, followed by the urge to print for example miniatures of persons/buildings. No I’m able to photograph an object/place, run it through a chain of structure-from-motion-software and at the end I get a textured mesh. The Mesh itself needs a little work to get it to print, but for a hobby its ok :slight_smile:
Now I’ll try to get the mesh into Unreal, for walking through a room or something alike, but here is my problem:

When building for Android (tried ATC and ETC1), my mesh gets scambled as you can see in the attached picture. In the editor or even built for Windows it works. Building the Mobile Starter Content works flawlessly, so the problem has to be with my mesh.
Building with disabled HDR and Post-Processing (as read in another thread) doesn’t help.
Anybody any idea what would cause something like that?
If you want, I could upload the mesh (50MB) to a vserver of mine.

Thanks in advance.

How many vertices are in the mesh? 16-bit index buffers are used on mobile so you are limited to 65535:

Hi Chris Babcock,
thanks for pointing me in the right direction :slight_smile: It’s clearly above that limit, range of 300k and more.
I just reduced the vertices in meshlab to 25k. To my surprise, after importing the .obj-file into the engine, the staticmesh editor tells me it’s ~90k vertices. Of course the mesh is still scrambled, but looks better, so it’s the right way. Just have to find a way to produce a .fbx-file for import or import the .obj-file as-is.

Thanks for your help!
Thread may be closed :slight_smile:

The number of vertices may be increased by differing UV’s or normals; there is only one index in an index buffer to a vertex so a vertex must be unique in position and all other attributes so it may be duplicated as needed for each attribute combination needed.