Spherical Mapping is changing my mesh?

Hi all, I’m having an issue when trying to use sphere projection to unwrap an imported mesh (a procedurally generated geodesic sphere). Before the unwrapping process (inside unity) my mesh has 2562 (vertices/normals/uv), after unwrapping with blender it comes back as 2616 (vertices/normals/uv). does anyone know how i can keep this consistent with the original mesh?

i am a blender noob so it’s likely that i have overlooked something obvious.

Thanks for the help!

What do you mean by ‘vertices/normals/uv’ ?

Supply a demo blend file and clearly explain what you are talking about and what the problem is

Thanks for the reply.

The number of vertices in my mesh is being changed by sphere projection.

I can confirm that this is occurring by comparing the length of the vertices array in the unity generated mesh (2562 vertices in the array), importing an obj of the mesh into blender, running sphere projection (I’m trying to unwrap the provided sphere), and saving an obj file back inside unity and looking at the length of the vertices array in the updated mesh (2616 vertices).

I have tried the whole process step by step without applying sphere projection, and the numbers came back the same so I have effectively managed to eliminate the other steps as the cause…

I was hoping to be able to just unwrap the provided mesh without adding any additional vertices…

Any ideas on how i can achieve this?

After-SphereProjection.blend (1.05 MB)Before-SphereProjection.blend (1.05 MB)

I am not sure if this applies here but some game engines break up the mesh depending on UV coordinates.
One Vertex in a mesh can be split up in several vertices in its UV-map. So if you change the UV map and then export it back to Unity it might count this new UV vertex count.

please provide a *.blend file so we can see what you are doing
I use " simple Cylindrical " maps all the time for asteroids and planets

normally it is a easy task

Tried to post these several hours ago but they did not appear…

regarding the vertices, I’m getting the length of the vertices array inside unity (2562) before exporting a obj file of the mesh. Next I’m importing the obj into blender and using sphere projection to unwrap the mesh. next i save as an obj and take back into unity and look at the length of the vertices array and it is now (2616). the normals and uv are also in arrays of the same length…

I was really hoping i could unwrap the mesh without changing the number of vertices…

also, I tried the whole process without applying the sphere projection and got the same number which narrows it down too the unwrapping somewhere.

anyway I’ve attached a blend file of the before and after the sphere projection stage.

After-SphereProjection.blend (1.05 MB)After-SphereProjection.blend (1.05 MB)Before-SphereProjection.blend (1.05 MB)

Thanks for taking the time to have a look!

have a look at this slightly edit UV mapped blend file
i reset the normals and added spherical map

i still am not sure exactly what he issue is

do to the very low poly count the north and south pole are a bit ugly