Hangar lights?

Hello all! I’m in the process of (re)building an airport and all is going very well! But I do have one question.

I have several hangars that are open 24/7 and need to know what to do to make their interiors light up at night.

I tried fooling with the textures, but that didn’t work, (unless I still did something wrong). I was thinking along the lines of making a seperate interior and exterior. Have night textures only for the interior parts.

Am I on the right track?


Ocala Flight Sim Club

Is this a custom built hangar? You can either use the P3D v4 dynamic lights, and place them like effects.

Or you can bake or hand paint the lighting on the texture of the inside of the hangar. But then you must have non-overlapping UVs.

Kind regards,

Yes it is a custom built hangar. I have to make this for both FSX and P3D, so I'll assume the dynamic lights are a no-go, (even if I knew how to do it).

I'm not sure about "non-overlapping UV's". Not sure what you're referring to. Where can I find information and what are the symptoms of using non-overlapping UVs? (Image below?)

I'm not familiar with "baking" either. I need to know what the advantage to "baking" is.

I've managed to get around this by making a Night Texture "LM" file and only making the outside parts dark while interior parts are not darkened out. Seems to work, BUT I'm now getting light through the "seams" of the walls, roof etc. (see image) and not real sure why! My vertices are welded together and the face is a solid face (edge that was going from one corner to the opposite corner was dissolved). Is this a result of "non-overlapping UV's"?


That's the way you do it, with a _lm texture, you can use programs like blender to bake the lights of the textures, and ambient occlusion etc.

I assume you are getting seams because the walls are a single plane, have a thickness to them.

Kind regards,

I removed my original reply, because I (may have) misunderstood your answer. The walls are not a single plane, but are a "box" where one wall is the interior, the other is the exterior. (so I guess each wall IS a single plane in reality). I tried applying a "solidify" modifier, and changed the thickness to 1/2 inch it made no difference. (I did select ALL faces first) And I'm using Blender.

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Can you show your UV layout and texture sheet?

It's good practice to leave 2-3 pixels border around each UV unwrap to stop from spillage.

Kind regards.

I've deleted my "older" UV layout sheet, and do NOT ever run into each other. I do not have "spillage" because I do not always use the full "layout" for any individual part, but rather shrink it down just a tiny bit to prevent encroaching the boarders with my "face" I'm texturing. When I create the layout, (still a learning process), I do leave some space between items, but sometimes their edges do touch.

I can possibly send you something if still necessary.

I'm also not sure how this would play into my mesh leaving (essentially) a gap in the face when in Blender it shows as one face. Not two faces made of 2 triangles. (I've dissolved the edge in the middle).


I'm still not sure what to do about the "light" coming through the seams of the mesh on my night hangars. (See image above). This happens in FSX and P3D v4. I'm not sure if it is a Blender issue, a Blender2FSX/P3D issue, a ModelConverterX issue or a "ME" issue (a setting not correct in any of the above. The issue is NOT my _LM" texture "spilling" over onto another unlit area. The light is coming through the seams of the hangar walls / roof...

The hangar is constructed in Blender. For simplicity, lets say each wall is a "box" with one plane of the box being the outer wall and the other plane being the inner wall. I used a _LM texture to make all exterior walls dark and interior walls not dark.

The light is coming through the walls where I dissolved an edge that was going from one corner to the other making the face one part instead of two (in Blender). In an attempt to resolve this issue, I also deleted this "wall", and created a new one by simply selecting 4 vertices and hitting "F" to create a new face, but the same issue happened.

This issue does NOT show up in ModelConverterX when I switch to texture night render mode, (also "Use complex Shader" is enabled).

Any suggestions would be great.


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Resource contributor

The reason for "light" coming through the seams is you... as stated before, its good practice to have the textures overlapping somewhat over the destinated UV areas.
Thank you for your reply, but I’m having a difficult time following your explanation. Are you suggesting that my texture that represents the “lighted” portions are encroaching on the non-lit parts? If so, that is not my problem. Please bear with me and I’ll try to convey myself better.

Your explanation would be correct if the light “leaks” were only at the edges of my wall or only at the edges of whatever is textured AND if I had open seams or open edges. I do not! ALL vertices are welded together and I have NO open seams on any surface. Wall vertices are welded together at all corners, and I do not have light leaks at any corner edge. Please look closely at the picture below. My light leaks are in the center of the walls and the center of all faces. It is ONLY visible at night (in FSX and P3D v4) when using textures to create dark outer walls and bright inner walls. It is NOT visible in ModelConverterX on day or night modes. All of my walls (inner and outer) are separated by about one foot, so they are not touching each other. Only on night mode, ALL of my faces have a phantom edge that runs from one corner to another. It is these edges that the light is leaking through and (unless I’m missing something) is irrelevant what my texture is doing. My textue is completely covering this phantom “edge”!


(Tomorrow I’ll try to attach a day picture so you can see the face and texture better. )

Let’s say I create the plane below. The light leaks through ALL edges inside the entire plane regardless of my texture and regardless if I dissolve those edges or not. You would get 3 light leaks at all 3 center edges.


Using “knife tool” or loop tool, I can create new edges anywhere on this face and will consequently get a new edge where light leaks through where it previously wasn’t leaking. NO changes were made to the texture, only added new edges.

Why is light leaking through the center of a face even when it is a single face and completely covered in texture? It’s as if there is a phantom edge that is not completely sealed.

If you (or anyone) wish I can make all files available for evaluation. I sure would like to get an explanation even if it is texture related.

Thank you for your help and patience.

Ocala Flight Sim Club


Resource contributor
I understand what your saying, but if the LM (light maps, depending on how they were created, could include the diffuse maps) are not covering to the edge or just beyond it, it will cause such anomalies.

I have seen this before when I first started modeling. It's not the how the structure was created (welded, etc) . The color or lack of at the edges could cause this or with the possible transparent alpha within the LM (light map).

The evaluating of the textures would help, yes.
Ok, I've placed a file called "Hangar Issues" on dropbox and can be found here. https://www.dropbox.com/s/azeo82bn97f6ds3/Hangar issues.zip?dl=0 It contains blender file, all Photoshop files used, dds files created from Photoshop files, MDL file and BGL file. Dissect it and see what you can come up with if you're interested.

My sequence of events were:

1. Created hangar in Blender 2.79.
2. Created all texture files using Photoshop Elements 7.0 I do not know if it has the capability of creating an Alpha file, I did not do anything other than create the .dds files and save them as a DTX 5 file.
3. Used Blender 2FSX/P3D (v 0.94) to export model as a FSX MDL file.
4. Used ModelConverterX 1.4 (and previous version) to create BGL file.
5. Used ADE 1.75 to place it into airport file.

I seriously appreciate your help and if you have the chance to look into this would also be appreciated. I will not have access to this computer for a few days but will still have access to emails.

The images below are of day / night modes. For the first time, I can see a seam in the day on the roof. IF you should open the blender file, as you will see the roof (as well as all walls) are a single face. Why is it still showing a seam? Ignore the flipping ultralight. LOL!

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Resource contributor
After taking a quick look (to see what I would be looking at)...

Your ".psd" textures, once they are converted to a ".dds" file, DXT5... etc... They both have an alpha channel that is causing the effect "light". Here are the alpha channels of each of them:

TBrysonHangar_LM (alpha).png

The 1st image is your _LM and the 2nd the diffuse. Anywhere that you see a color other than white (in this case "grey" or "black"), you will see "light". Anywhere that has the black or grey coloring, it will be transparent.
If the textures were overlapping the edges (where there isn't a "black" color visible) the "light" will not show through. In Photoshop Elements 7,... You were wondering if it had access to the alpha channel, it doesn't directly have control in the normal sense, but can be controlled by making sure the initial layer (or is labeled as Layer0) is always "white". Make sure to save it as part of the ".psd" file as well. So when you do convert to a ',dds" thd alpha channel will be white.

Also,... What you might want to do with the _LM texture, remove the lighting that isn't a part of the texture (the area where it's blank - what would appear as transparent - usually is represented as a checkerboard pattern). That is what is causing the darken areas in the alpha channel.
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Thank you for looking into this for me. I want to say I also saved the dds files as a dds 1 with no alpha and it made no difference, but I won’t have access to my system until late next week so I cannot confirm that.

I’ll update this post as soon as I can

Again, thanks for your patience



Resource contributor
There are 2 forms of DXT1. DXT1 with alpha and one without, though I have tested without an Alpha and didn't get anything with the transparent areas in the alpha channels. I'm sure you chose with alpha, It's good practice though to eliminate all problems no matter what form of DXT1 or DXT5 you use.

As stated before, I would remove the lighted spots that are outside the actual texture from the map (within the _LM .psd) and eliminate the black areas within the diffuse map. This will help eliminate any problems that could occur no matter what DXT you use.

The Differences between DXT1 and DXT5 are this:

DXT1 (with alpha) = the alpha channel can only have 2 colors and they are black and white (no greyscale).​
DXT5 = the alpha channel can have 256 colors (black and white, including greyscale and the rest of the colors).​
DXT1 (with alpha) = is smaller in file size (compared to DXT3 and DXT5​
Thank you Doug for your help, but neither of your suggestions made any difference. I saved the files (both diffuse and LM) with a totally white layer 0 and recompiled the .dds files from that. No difference. I verified my "alpha" was totally white using DXTBmp, viewing it in the corner window. Then I used DXTBmp to convert both .dds files to DXT1 with no alpha, still no difference.

Again, I want to make sure we are both on the same page. I'm not having issues with light at the seams or corners or edges of my buildings. I'm having lite come through where there is a phantom line on the face of the material from bottom left corner to top right corner where the material should be solid. My textures are solid (either black (LM) or paint (diffuse) in these areas. If you look closely at the last set of images I sent, (with the upside down ultralight), in the day image you will see a seam on the roof going from bottom left to top right. This seam is more visible on the night image. This is what I'm referring to and can't understand why that is texture related.

Thanks for your patience,



Resource contributor

Let me see what you did with the textures. I only have your previous ones, I still think its the textures... otherwise, it's the model and I saw nothing wrong with the model. I understand what you are referring to. Also, is there a reason why the floor of the hangar doesn't or is not reaching the walls?

Concerning the previous psd files as well... within the "layer0" layer there appear to be "hairline" lines black in color.
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I’ve noticed that even with a solid hangar the shadows can bleed through similar to what your seeing with the light

Could be a p3D rendering issue?