# Telescope mirror

#### droide

I am trying to model nice telescope mirrors...

Using a (R=100%, G=0%, B=100%) texture for the metallic texture, i get a perfect mirror effect in Blender :

but the result is not so nice when rendering in MSFS :

Seems similar if i de-activate the shade smooth in blender.
I am loosing this setting when converting to MSFS ?

#### trfsd

Can you show us the object in Blender in wireframe mode so that we can see the mesh?

#### Mikea.at

Try to model the object with rectangle faces. Looks like a ngon shading problem.

#### Cédrice

Resource contributor
Droide, show your model in edit mode in Blender

#### trfsd

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​

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​

### 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​

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​

9. Delete the single edge below the origin​

### 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​

### 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
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)

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​

### E. Export and use the mirror in MSFS​

2. Export the mirror object using Blender2MSFS add-on​

The mirror effect is far from perfect in MSFS, but still does a reasonably good job.

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.

#### Cédrice

Resource contributor
Perfect, good work I see that your mirror works as it should in the game, the reflections are not perfect in msfs but it is specific to the software

#### trfsd

What I would have liked was a mathematical Curve tool that I could use to directly make a 2D parabolic curve. The only tool I found for this job was the Math Function mesh object, which required me to then delete most of the mesh, leaving only the desired 2D parabolic curve. There is a rich selection of curve tools in Blender, but none that I could find that would allow me to enter a specific math function.

#### droide

Thank you all for your precious help.
I will try to apply the recommended reciepy, but would like to reuse my existing models at first.

I attached my model for those who requested to take a look at the mesh

#### Attachments

• SCTm.zip
175.6 KB · Views: 36

#### droide

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​

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

### 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
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​

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.

Great, another astronomer !

If you are in the process to modeling some famous telescopes for MSFS, tell me.
I started the process to convert my series of Xplane scenery for MSFS, and this would be a pitty we do the same work.

You can find my original work for Xplane here.

in total there are 7 observatories : all Chilean telescopes, all Hawaian and Canarian.

Converting to MSFS could take me monthes

#### trfsd

No, I am not modeling any famous observatories. I was just having fun with the challenge of creating a 3D model of a telescope mirror in Blender. I did this years ago in Autodesk Inventor, but I am still just learning my way around Blender. So it was a useful learning exercise.

#### trfsd

@droide, I looked at your model, and I think that the mesh is going to make your life difficult. It is not symmetrical and has lots of surface anomalies. Trying to clean up that mesh will take a lot more work than simply recreating the object from scratch.

What are the specs of the mirror that you are trying to replicate? From the model name, I assume it is a Schmidt-Cassegrain. The diameter appears to be roughly 9.6 meters, with a central aperture of roughly 2.8 meters in diameter. I can't guess at the focal length, since the model appears to be completely flat.