Skybox window backdrops?

[Orwar]

   A while back, I decided to update my skybox by putting in some windows, but since I'm using local lighting sources and have a completely dark WL on my parcel, the view is a bit... Boring. So, I've been thinking about putting up a backdrop outside, but can't decide which is the best way to do so.

   I've noticed that some other creators build little inverted boxes with a texture, which gives you that illusion of depth to it - but I've also noticed that recycling the texture may give some rather weird effects, especially if you stand in a room and have an Eiffel tower in every window, even the ones that are looking 'out' in a different directions. One way to get around this effect which of course immediately pops any suspension of disbelief would of course be to use different textures, or just picking a more abstract backdrop that isn't quite as obvious - alternatively I just make a single, large backdrop that covers all of the windows, but then the texture resolution is most probably not going to be particularly appealing. So whilst playing around with a few different setups I thought I'd just ask, how do other builders approach this issue?

[Mollymews]

most I have seen done well at high resolution, chop a very large pictorial scene texture off-world into separate textures, then apply them as appropriate to each viewable window box face.  Some also link the boxes, so can more easily do scripted texture scene changes

[Orwar]

15 minutes ago, Mollymews said:

most I have seen done well at high resolution, chop a very large pictorial scene texture off-world into separate textures, then apply them as appropriate to each viewable window box face.  Some also link the boxes, so can more easily do scripted texture scene changes

   I did consider that, but it goes against my principle of trying to keep down the texture memory. Perhaps it's worth it though, if it looks that much better.

[Da5id Weatherwax]

Here's a somewhat involved workflow in your 3d prog of choice that will give you a consistent view out of all windows. Begin with a mesh sphere, normals pointing inwards. map its UVs using the same geographical projection used for background HDRIs in rendering. Use such an image for your texture, suitably downscaled for SL, of course. Now, for each aspect for which you have facing windows, take that sphere *at zero rotation*, copy it and delete the vertices that would make up the "inside half" when looking out that particular set of windows. Upload the hemispheres for each aspect and stick them on the outside of your windows. Make sure they are all the same size in SL. Apply your texture to 'em.The view out of each window will be different but will combine to a consistent 360 view. because the UV for the undeleted vertices will take care of rendering the right part of the texture on each one.

 

Edited to Add:

Something was bugging me about the above description and I realized what it was - it's been a while since I made one of these and so I made a test piece on the beta grid to confirm... Projecting a full hemisphere outside each window is too much. For an individual window it looks fine but if you can see two windows at different angles you see duplication. You want the individual "pieces of the sphere" outside each window to be about a 120 degree horizontal angle of the original sphere, but distorted - AFTER you equirect project and trim - in blender, or whatever prog you use, to be a hemisphere - and therefore cover the full field of view outside the window - when uploaded. Leave the vertical as a full hemisphere, minus the poles of course because you really cant uv-map a pole in an equirectangular spherical projection, the math goes to infinity. Some folks map the ring of tris around the pole separately and collapse them to degenerate point on the UV map but I just delete the poles from the original sphere. Unless you cam right up to the window while looking vertically up or down, you'll never see the hole.

Edited July 11, 2019 by Da5id Weatherwax
Addendum

[Kyrah Abattoir]

Adding a bit of glow can give a good feeling that light is being emitted from that fake outside, maybe using emissive mask mode too.