Signal Light Textures with Custom Mipmaps: How is it Done?

[PerryPlatypus]

Most of us have seen the huge signal improvements brought by Maple Leaf Track's Siglight.ace with its custom Mipmaps that expand the light as you get more distant from the signal, for a more realistic viewing experience of distant signals. Does anyone know how to add these custom mipmaps where the texture expands in size as you get further from the object? I am trying to create some new signal textures, but I cannot figure out how to implement this expansion in light size.

Is this an obscure trade secret that only a select few know how to implement, or does anyone on the forums know how this is done?

[bcrailfan]

Is this an obscure trade secret that only a select few know how to implement, or does anyone on the forums know how this is done?

Sean : While it may sound like a trade secret, it actually wasn' t, as the SigLight texture file itself, had been made available at the former Mophouse Forum ( I have made a few b/u copies, "just in case" ) . The practical side, is that there are very few, who understand the functional principles, of such mipped textures. If you can get a hold of Jovet, I do know he understands how this works enough, to explain it, to others. The only question, really , is to find out if your own textures, would work flawlessly, on different computers / installations, Open Rails, and so on. While it may work on your own installation, it may cause embarrassing "artifacts", on some others.

Altogether, though, I would agree that, we are "not there yet", to replicate just how signals really look, from medium, to extended distances. Those mipped siglight textures were a step in the right direction, though.

Jean Brisson MSTS Route Builder,

[PerryPlatypus]

Jean,

I don't have a problem as far as obtaining MLT's Siglight.ace, but my trouble is I am trying to create textures for use with Mullan Pass (payware). And the particular signal I was attempting to create a texture for (a yard switch indicator) does not look right at all with MLT's Siglight. It seems that SLI (now TS) has a slightly less powerful version of Siglight on their routes, but once again, it does not look right for the switch indicator, which has a square-shaped light that looks nothing like a standard signal lens. From a distance looks okay, but up close, not so good. It's not a necessity, but if I can find out how to do it, I would like to. I will attempt to contact Jovet soon, thank you for the advice!

[TrainSimulations]

I was the one who did the original siglight.ace for MLT, and subsequently for SLI. At the time, there was no way to alter the mipmaps directly, and I had a tool from Microsoft to allow for export of ACE files directly from Photoshop. I messed with one of the settings and by a stroke of luck, the mipmapping worked out the way it did. There is an easier way to do this today, if you are an Adobe Photoshop user. If so, download the Nvidia DDS tools, to allow you to export to DDS format from Photoshop. Build your siglight file with visible mipmap levels, and "paint" them the way you want each level. Then, export as a DDS file, preferably DXT3 format. You will then have a DDS file with the appropriate mipmaps. Open the DDS file with ACEit, which is included with Route Riter. Export the DDS file as an ACE file, with alpha, and if my memory serves me well, it should retain the mipmaps from the DDS file, and you should be good to go.

Give it a try anyway.

Regards,
Jason@TrainSimulations.net

[Bananarama]

I believe Jason was the first to monkey with the files in a commercial product, but it was Scott Miller and also John "Mosaic" Stanford who, working independent of each other, figured out the usage of reverse mips in MSTS. IIRC, John had even used the signal textures in his Crawford Hill route, but instead of using DDS, he programmed his own reverse mipmap utility. He sent me a copy in 2003~2004, but I lost it long ago in a hard drive failure. Since then, however, I've been using the method Jason outlined above to reverse the mipmaps where necessary.

BTW, John's latest signal texture (2007) is included in both the Feather River and Sherman Hill routes.

[PerryPlatypus]

Someone has pointed out to me that it turns out the Guru's at Open Rails have already implemented a workaround that gives smooth and consistent results, and does not require the use of custom Mipmaps. By using a single lens texture with a normal radius value (in the neighborhood of 0.1 meters) and turning on the Open Rails experimental option "Signal Light Glow", it replicated what has been attempted with Mipmaps without the need for the custom mipmaps

By the way Jason, I have been trying to contact you via email and Private Message, I'm not sure if you have gotten any of them.