As an amateur astronomer and telescope builder, this thread inspired me to try my hand at making a telescope mirror in Blender that looked halfway decent in MSFS. I made a parabolic mirror for a Newtonian telescope, but the same techniques that I describe below would also work for a spherical mirror in a Catadioptric telescope like the one that
@droide was making. I apologize for the lengthy post that follows. But hopefully some of you will enjoy it.
Making a parabolic telescope mirror
A. Create mirror surface
1. Enable "Add Mesh: Extra Objects" add-on (if not already enabled)
2. Add / Mesh / Math Function / Z Math Surface
3. Edit Z Equation = (x**2 + y**2) / (4 * <MIRROR FOCAL LENGTH>)
4. Set X and Y subdivisions to an odd number (e.g., 17)
5. Set X and Y size to mirror diameter
View attachment 71510
B. Create mirror profile
1. Add / Mesh / Plane
2. Set Size to mirror radius
3. Rotate 90 degrees in the X axis
4. Set X Location to mirror radius / 2
5. Set Z Location to ( mirror radius / 2 ) - mirror thickness
View attachment 71511
6. Use BoolTool to intersect mirror surface and vertical plane
7. Switch to Edit Mode using Vertex Selection
8. Delete all vertices in the mirror surface except those on the X axis from zero to the mirror radius, inclusive
View attachment 71512
9. Delete the single edge below the origin
View attachment 71513
C. Create mirror object
1. Select the resulting curve and apply a Screw modifier
2. Set 360 degrees, no screw, 1 iteration, 32 steps, and merge vertices; leave Normals set to Smooth Shading
View attachment 71514
4. Return to Object Mode and Apply the modifier
D. Adjust normals and apply textures
1. Create a new mirror material (e.g., Metal=1.0, Roughness=0.0) and apply to the entire object
2. Return to Edit Mode
3. Make a loop cut in the outermost ring on the top surface and slide the cut very close to the outer edge (e.g., Factor = -0.8)
View attachment 71515
4. Create a matte black material (e.g., Color=<0,0,0>, Roughness=1.0)
5. Using Face Selection mode, select the narrow outer ring on the edge of the top surface
6. Set these faces to Shade Flat and apply the matte black material
7. Select the entire bottom surface of the object
8. Set these faces to Shade Flat and apply the matte black material
9. Select the sides of the object
10. Apply the matte black material, but leave the faces set to Shade Smooth
View attachment 71516
E. Export and use the mirror in MSFS
1. Return to Object Mode
2. Export the mirror object using Blender2MSFS add-on
View attachment 71517
The mirror effect is far from perfect in MSFS, but still does a reasonably good job.
View attachment 71518
For a Catadioptric mirror, use a spherical curve for the Z Equation, and shift the vertical plane further out on the X axis so that you leave a hole in the center of the mirror. Otherwise, the rest of the steps should be roughly the same. I am sure that there is an even better way to create an optically correct telescope mirror in MSFS. But this seemed like a good approach to me. In any event, it was a useful learning experience and a lot of fun.