Blender mirror modifier doesn't export mirrored half

Question

When I use mirror modifier in blender and export my collide (.dae), my exported object doesn't have include the 'mirrored half' but just has the side where I didn't delete the faces.

Help?

Answer 1

When exporting to DAE, look in your Toolshelf Properties and try selecting "apply modifiers"

Update: For Blender 2.92.0 (on Mac), try here:

Answer 2

If mirror modifier is not applied, all mirrored vertices are not considered as "true" vertices. You just have to apply the mirror modifier in object data panel.

Answer 3

While exporting as glTF (.glb), checking the Apply Modifiers under the Data -> Mesh options fixed this issue for me. Blender version 3.6.4.