world Hdri’s will only give reflections in perspective views in orthographic they will just give one plain colour. In cycles you can make a large sphere and map your hdri to it with an emission shader set to 1, put it in its own collection and in view layers set to indirect only. Then you will get the reflections in orthographic mode.
For eevee this option does not work.
It is actually reflecting one pixel per face.
If you curve your plane a little you will start to get reflections the more you curve the higher res they get.
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Edit:
Easy solution, just found that shade smooth will fix it:
Shade Flat
It sounds good, thank you for the insights.
I think we are dealing with a different issue. My reflections are gone when I am in an orthographic camera. Even adding a sphere did not work.
But now I found out its a bug i think. It does not show if the mesh has a glossy node …If i use a principle node works…
Funny
In cycles I got those black bits in the cube with smooth shade, I had to add a bevel to correct it.
Note that in Eevee there are no black bits but the reflection does have a counter spherical distortion at the edges which is also corrected with the bevel.
For the plane smooth shade alone did not give reflections (just plain 1 pixel colour), so I added a slight solidify modifier, I also got a “counter spherical” black bit so I had to give it a bevel as well.
I hope this makes sense.
I think it all has to do with the normals and the fact that smooth shade will “bend” them. Then how light rays will bounce on them.
It’s not really a bug…
In Orthographic view, all rays from the camera are parallel.
When they hit a plane, the reflected rays will also be parallel to each other.
If the reflected rays only hit the environment map, they will only reflect one single coordinate of the environment resulting in a flat color, since environment coordinates are just calculated from the ray direction (and parallel rays all have the same direction).
If, on the other hand, you have scene objects to be reflected, they will reflect as expected.
can you share an image of your setup? the original image you shared shows the correct results from an orthographic reflection of an hdri, as explained by Secrop