Realistic Sky Dome Textures for Open Rails

[EvolutionMan]

As many of you know, the default OR environment textures have been around for a long time. While there have been several attempts made to improve the appearance of the sky before, I thought that I'd give it a try myself. At the same time, I thought that the clouds used in rain and snow conditions needed some more variation. This resulted in me making several new sky textures to bring the visuals closer to realistic.

First, a few notes:

- The rain and snow cloud textures are modified versions of the default cloud texture, being given a colour change that's more in line with what I've seen in real life. The rain and snow particles themselves are modified as well (the snow texture was not made by me).
- There are two variations of clear skies, as I've noticed that their appearance in real life can vary depending on lighting and atmospheric conditions.
- The default environment files for rain and snow include some fog and/or lots of clouds. High values for each can interfere with the appearance of the textures, so the values were set fairly low for those conditions.
- Since the sky dome textures include no other elements than the sky itself, it means that any distortion due to the shape of the sky box is barely detectable.
- There is no sun to be seen in any of the textures, so they are perfectly suitable.
- My main goal is to make them accessible and interchangeable (using a specialized system of batch files), so don't expect any dazzling visuals or the like. After all, not everything is perfect.

Attached, you will find screenshots of the sky texture sets that I have made. All are taken in the same location to give an idea of perspective and ideal lighting conditions.

Clear:
DC.ClearSkydome.png

Clear (vibrant; ideal for warmer weather):
DC.ClearVibrantSkydome.png

Clear (with distant clouds; perfect for a hot summer day):
(Unfortunately, this one is affected by the distortion of the sky box. I was also limited to the resolution and size of the photo that was used.)
DC.ClearWithDistantCloudsSkydome.png

Overcast (dark; ideal for just before a rain shower):
DC.OvercastDarkSkydome.png

Rain Shower (of course, the name says it all):
DC.RainShowerSkydome.png

Snowstorm (again, the name says it):
DC.SnowstormSkydome.png

All of the textures were made from public domain sources (photos for most of the material, and existing default OR assets for the rest). The sky dome textures for the rain and snow environments are new, using colours sampled from photos. A few minor modifications were made afterwards to slightly improve their appearance and remove a few visual artifacts that came about after the conversion (no colour changes were involved).

Curious to hear your constructive feedback on these sky textures, pertaining to how they appear so far and if there's any improvements/changes you suggest. Personally, they look good to me as is, but others could see them differently.

I used a unique method to make each of those textures (save for the modified default OR assets), which I could explain later on, if anyone's interested.

[derekmorton]

You have our interest, thanks.

[qballbandit]

I probably have every skydome1 & clouds01 files made available, and some not made public. I mix and match based on my local conditions when I am running a train. I also use Reshade to add additional options.
What you have is a great start, and any additions of these files made public is a win. I thank you and wish you luck, and hope that you continue to share your progress. I'd be happy to add them to my collection!

[bnsfsd40-2]

I agree with the previous speakers and also express interest! 😊

[trainlover2923]

I agree with everyone else....You caught my interest. Keep up the good work

[EvolutionMan]

Appreciate your feedback on these.

Looks like most of you are in favour of a tutorial! I'll go ahead and work on that, then post it here in this thread when it's done.

[lineman]

Thank you!

[EvolutionMan]

EvolutionMan's Sky Dome Texture Tutorial

In this tutorial, I'll explain the basic process that I use to make sky dome textures, so that you can try making your own. I'd be interested to see if you get anything out of the information provided here.

I use Paint.NET as my image editing software, which you can get here. You'll then need to install the Polar Kaleidoscope plug-in, which can be found here. This will be necessary in order to transform the texture into a dome, like what I have done.

For this tutorial, we'll be using this image (which I used to make the clear sky dome texture - it's in the first screenshot in the first post of this thread here).

Part 1 - Making the Texture

First, open the sky image that you want to use. Ideally, it must not have anything within the sky itself (e.g. clouds), as they will be otherwise stretched to horrid proportions following the conversion.

Select a portion of the texture that is closest to the horizon in the photo (a.k.a. the section that is closest to the ground).

Sky_Dome_Tutorial_1.png

Copy that section into a new image, ensuring that the lighter colour of the gradient is at the bottom edge of the texture. This will be essential for the transformation to work as intended.

Sky_Dome_Tutorial_2.png

Next, you'll need to resize the image to use a power of 2. In my case, I used 1024 x 1024 pixels, but you could use anything larger or smaller and it would work equally as well. The Absolute Size option will need to be selected, with the Maintain Aspect Ratio box unchecked, in order to manually change the dimensions. Make sure that Bicubic resampling is selected, as I've found that it yields the smoothest result.

Sky_Dome_Tutorial_3.png

Click OK to apply the new dimensions to the texture. It should look similar to what is shown below.

Sky_Dome_Tutorial_4.png

Once that's done, you'll need to open the Polar Kaleidoscope plug-in, which can be found in the Effects > Distort sub-menu. Since it's a third-party plug-in, it should have a green puzzle piece icon next to it's name.

Sky_Dome_Tutorial_5.png

A small window will appear, and the texture conversion will be previewed in real time. In order to get the realistic perspective, change the settings in this window. I'll list mine so that you can try and follow along:

- Pieces should be set to 2

- Zoom Out should be set to 2 (this will allow the actual edge of the sky dome to reach the edge of the texture bounds)

- Full Transform should be enabled

- Quality should be set to 3 (this allows the texture to appear smoother instead of more stretched; the default value is 2, but you can adjust it to what you prefer)

Sky_Dome_Tutorial_6.png

Click the OK button to apply the settings you specified. If done correctly, your texture should be transformed into a dome, with the reflections appearing to be consistent.

Sky_Dome_Tutorial_7.png

Don't try to save it just yet. There's one more small thing that needs to be taken care of. If you look closely at the texture, there's a good chance that you'll see stretched pixels and messy areas here and there. Now, the trick here is to hide the imperfections.

I added a very slight Gaussian blur to my sky textures to do exactly that. Open the Effects > Blurs sub-menu and click on the Gaussian Blur entry. (You can see that I have some additional plug-ins installed - you never know when they might be useful.)

Sky_Dome_Tutorial_8.png

A small window will appear. Then, set the blur radius to 7. This will ensure that the base appearance remains while the texture doesn't get "washed out" too much.

Sky_Dome_Tutorial_9.png

Save the file in PNG format, and now you have your own sky dome texture!

Sky_Dome_Tutorial_10.png

Although this tutorial uses Paint.NET, other image editing software programs come with similar features (either by default or in the form of plug-ins) that can achieve a very similar result.

In the next part below, I'll outline the process that I use to set up my sky dome textures for use in Open Rails, as well as switching texture sets between sessions.

[scottb613]

Hi Folks,

I love it when people take the time to help other people out - the wavy distortion can be minimized - by using a later version of ORTS - I worked with James on improving this - a way back. Keep up the good work!

Welcome aboard...

Regards,
Scott

[EvolutionMan]

Part 2 - Setting Up the Texture Folders and Batch Files

Now, this is where you'll set up your textures for use in the simulator. Before you do this, you need to have Open Rails (the base simulator program, not your content) installed in a non-default location - that is, anything other than the Program Files folders on your operating system.

In the Open Rails Content folder (within the base OR folder - you'll be using this for the rest of the tutorial), make a new folder with the name of the sky dome texture set that you want to use. Copy the sky dome texture you just made into that folder and name it SkyDome1 - exactly the same as the default sky dome texture that OR uses.

The directory should be as follows:

Open Rails > Content > Skydomes > (Name of Skydome)

Replace the (Name of Skydome) text, including brackets, with the name of your custom sky dome texture.

Then, using Paint.NET again, make a new image using dimensions that are a power of 2, but smaller than your main texture. In my case, I used 256 x 256 pixels. Select the background and delete it. Then, save it in PNG format. Copy this file over to your sky dome texture set folder (the one the batch file will use) and name it Clouds01 - again, exactly the same as the default cloud texture that OR uses.

I use a batch file system that checks for all required files and automatically copies them to the Content folder if the condition is met, overwriting without user input.

Open your word processing application and copy this bit of code in. I use Notepad in my case.

@echo off

:start1
if exist (Name of Skydome)\SkyDome1.png
goto start2
goto unable

:start2
if exist (Name of Skydome)\Clouds01.png
goto copy
goto unable

:copy
call xcopy .\(Name of Skydome)\SkyDome1.png .\..\SkyDome1.png /Y
call xcopy .\(Name of Skydome)\Clouds01.png .\..\Clouds01.png /Y
goto complete

:unable
echo The action could not be completed. Unable to swap sky dome texture set.
echo Please check your Open Rails installation to make sure the textures are located in their proper folders.
echo For reference, within each folder, the textures should have the same names as the default textures used.
echo The folder names should use the same names as the batch files.
pause
goto close

:complete
cls
echo The action was completed successfully.
echo Skydome texture set currently being used: (Name of Skydome)
pause
goto close

:close
cls

Replace the (Name of Skydome) text, including brackets, with the folder name of your sky dome textures. If you don't prefer using my code, you can try using a different type of batch file that simply copies the folder's contents over to the Content folder.

Then, save it as a batch file within the Skydomes folder (within the OR Content folder - which itself is in the main program folder). To do this, near the bottom of the Save As window that appears, select the All Files option. After this, remove the existing file extension name (.txt) and replace it with the batch file extension (.bat), then click Save. For consistency, I would make the name match that of it's corresponding sky dome texture folder, so it clearly indicates which texture will replace the one currently in use.

If done correctly, a batch file will be present in your Skydomes folder. Don't run it yet! Before you do so, make a new sub-folder within the Skydomes folder and back up the default OR sky dome and cloud textures or the other textures you're currently using into that folder. If you're using the default textures, I would name that folder Default.

Now, run the batch file. If executed correctly, your sky dome and cloud textures should be replaced with the new ones you had just made earlier in the tutorial.

Start up Open Rails and see if your new texture works. If it does, then you're all set!

DC.ClearSkydomeInGame.png

You can always check and see if any imperfections need to be addressed, then go back and make those changes before saving, replacing the older file, and running the batch file again. Some of the steps in the first part above will need to be repeated if you make any later edits. I always save each version of a texture differently, so it's easy to go back in case something doesn't appear as you intended.

That's all there is to it. This method might seem complicated at first, but follow the instructions carefully as described above and you'll start to get the hang of it.

I hope this tutorial is clear and easy to follow. Feel free to let me know if you have any issues following the process.

[bnsfsd40-2]

I'd like to thank you for your instructions. I now have the ability to set the appropriate sky for each trip.

For example, I used a picture from last Sunday where there was thin clouds/haze in the air. I experimented a bit, then set it to autumn, and it looks wonderfully harmonious.

Open Rails 2025-09-10 06-21-39.png

[EvolutionMan]

I'd like to thank you for your instructions. I now have the ability to set the appropriate sky for each trip.

No worries at all, Daniel. Happy to hear that you haven't faced any issues.

The sky dome texture you made looks really nice! It fits the scene well.

[CSRX]

Gave it a try with one of my own photo from last fall. Seems kind of bland without any clouds but worked out great. I couldn't get the batch file to work correctly, but that's okay, old school copy & paste still worked fine.

[EvolutionMan]

I couldn't get the batch file to work correctly, but that's okay, old school copy & paste still worked fine.

Looking good, Shawn. Glad this tutorial was of use.

The batch files were primarily intended for those users who don't know as much about content creation/modification as others like both of us do. Some users would only be running trains in-game and not modifying existing content for their own use. The batch files were intended to make it easier for them.

I could attach my batch files here, for anyone who's having trouble getting them to work.

Seems kind of bland without any clouds but worked out great.

As for the lack of clouds, this type of weather scenario does occur quite frequently. It only feels natural to have that sort of sky dome texture and use it often - no pun intended.