is this one of the used images?
Yes, by compute mesh I thought Create Model. It could look as point cloud, as there is a restriction for models smaller than 40 M tris. When you simplified it, you should be able to see the mesh. Do you have selected Solid option in Scene render under Scene 3D tab/View:
Were both datasets aligned into one component after alignment? What was the original size of computed model (which you simplified to 5 000 000 tris)?
Is it possible to show the 3D view also with the aligned images?
There is an option Close holes in Scene 3D tab/Tools, which you can try.