What is DXTbmp, and how do I edit flight sim textures?

DXTbmp is a free Windows texture-conversion utility for classic Microsoft flight simulators, chiefly FS2004, FSX and many Prepar3D add-ons. It opens extended BMP and DDS textures, separates the colour image and alpha channel for editing, then saves them with simulator-compatible compression. Paint in another image editor; use DXTbmp to preserve the texture format.

What does DXTbmp actually do?

DXTbmp acts as a bridge between a flight simulator texture and a conventional image editor. It is not a layered repaint editor: its job is to decode simulator textures, display their alpha channels and write the finished artwork back in a format the model can load.

This matters because an FS-era .bmp file may be an extended bitmap containing DXT compression rather than an ordinary desktop bitmap. Opening and overwriting it directly in a basic editor can remove its compression, alpha channel or mipmaps. DDS files carry similar risks if the editor uses unsuitable export settings.

The alpha channel is a greyscale image stored alongside the colour texture. Depending on the model's material settings, it may control transparency, reflectivity, specular behaviour or another effect. White does not universally mean “more shine” or “more transparency”; the model determines how the channel is interpreted.

You can download DXTbmp from our library when working with these older Microsoft simulator formats.

How do you edit a flight simulator texture with DXTbmp?

The safest method is to preserve the original file as a reference, edit an uncompressed working image and perform only the final conversion in DXTbmp.

1. Back up the complete texture folder. Copy it somewhere outside the installed aircraft or scenery package. Add-ons often share textures between liveries, so overwriting what appears to be one repaint can affect several variants.
2. Identify the correct texture file. Confirm the selected aircraft's livery folder and note the exact filename, extension, dimensions, compression type, alpha channel and mipmap status. In Microsoft aircraft configuration files, a value such as texture=Red normally selects the texture.Red folder.
3. Open the original in DXTbmp. Check both the main image and alpha preview. Save a separate copy of the alpha if the file has one; that gives you a clean version to restore if it is accidentally changed.
4. Send or export the colour image to your editor. Use DXTbmp's external-editor facility or export a lossless working image. Keep the original pixel dimensions and canvas orientation. Resizing a texture or changing its proportions will no longer match the model's UV mapping.
5. Paint on a layered master file. Keep logos, colours, panel lines, rivets and weathering on separate layers where possible. Export a flattened copy for DXTbmp rather than repeatedly editing the compressed DXT file, because each recompression can introduce more block artefacts.
6. Edit the alpha separately only when required. It must remain a greyscale image with the same dimensions as the colour texture. If you are only changing paint or markings, retaining the original alpha is normally the safest choice.
7. Reload the edited image into DXTbmp. Verify that the colour image and alpha preview are both present before saving. Do not assume an alpha embedded by the paint editor has been imported correctly; DXTbmp treats the main image and alpha as separate components.
8. Match the original output format. Preserve the .bmp or .dds container, DXT compression and mipmap behaviour unless the add-on documentation explicitly calls for something else. Let DXTbmp handle the simulator texture orientation rather than manually flipping files during an otherwise unchanged round trip.
9. Save and verify a test copy. Reopen the newly saved file in DXTbmp and check its dimensions, format and alpha. Only then copy it into the livery or scenery texture folder.
10. Inspect it inside the simulator. Check the aircraft in daylight and at night, from close range and at a distance. Switching aircraft may reload the texture, but a complete simulator restart is the dependable fix when an older simulator continues displaying a cached version.

Do you need a paint kit?

A paint kit is not compulsory, but it is much easier to produce a clean repaint from layered source files than from a flattened, compressed texture. Painting directly over baked panel lines and shadows tends to soften details and creates visible blocks around lettering.

For a practical example, our T-6G Texan package includes layered Paint.NET texture sources, including panel-line, rivet and alpha-channel references that demonstrate how repaint elements can be separated.

Which DXTbmp save format should you choose?

Choose the same container and compression used by the original texture unless you understand the model's material requirements. Modern graphics terminology may call DXT1, DXT3 and DXT5 BC1, BC2 and BC3 respectively, but DXTbmp uses the older DXT names.

Do not convert every texture to DXT1 merely to reduce file size. Glass, polished surfaces, propeller discs and some night textures rely on alpha precision. Likewise, removing mipmaps may make a texture look sharp up close while causing shimmer and unstable detail at a distance.

Why does the edited texture look wrong in the simulator?

Most broken repaints are caused by the wrong file, a lost alpha channel or output settings that no longer match the original.

• The aircraft is flat or excessively shiny: restore the original alpha and compare again. The colour artwork can be correct while the material response is completely wrong.
• Windows, fences or propeller discs are solid: the alpha may be missing, inverted for that material or saved in a format without the required gradient.
• The whole texture is transparent: the model is interpreting the replacement alpha differently from what you expected. Restore the original before trying to reverse it.
• The simulator shows white, black or corrupted surfaces: check the filename, dimensions, BMP or DDS container and compression type. A valid image file is not necessarily a valid texture for that model.
• Nothing changes: you may have edited the wrong livery, a fallback texture or a file that the model does not use. Also check for stale texture caching and Windows folder permissions.
• Markings are mirrored on one side: this is usually a model UV-mapping limitation, not a DXTbmp fault. Some aircraft map both sides of the fuselage to the same texture area.
• Text and registrations look fuzzy: confirm that the image was not resized and avoid repeated DXT saves. Fine lettering exposes compression damage quickly.
• The repaint shimmers at a distance: regenerate or preserve suitable mipmaps. Missing mipmaps force the simulator to scale the full-resolution texture in real time.

How can you tell if you edited the wrong texture file?

Check the aircraft's configuration entry and any texture.cfg file inside the livery folder. A fallback entry can pull wings, virtual-cockpit parts or shared fuselage textures from another folder, so the file visible in the simulator may not exist in the repaint folder at all.

If only one section refuses to change, temporarily apply an obvious test colour to the suspected texture and inspect the model. Restore the backup immediately afterwards. Never rename multiple files at random; exact texture filenames are assigned by the model.

How do you install the finished texture as a new repaint?

A separate repaint needs its own texture.name folder and a matching aircraft configuration entry; copying a texture into the aircraft directory alone will not add it to the selection menu. Our FSX repaint installation guide explains the folder and aircraft.cfg setup without requiring you to overwrite an existing livery.

Can DXTbmp edit MSFS or X-Plane textures?

DXTbmp is mainly suited to FS2004, FSX and compatible Prepar3D-era add-ons. It may open some files used elsewhere, but opening a DDS file does not mean that DXTbmp can preserve every material channel or compression mode it contains.

Modern Microsoft Flight Simulator aircraft commonly use PBR materials with separate or channel-packed albedo, normal, metallic, roughness and ambient-occlusion data. X-Plane aircraft also use their own PNG, DDS and normal-map conventions. For either simulator, follow the aircraft developer's documented texture workflow rather than passing PBR maps through DXTbmp, which can discard or alter data that is not represented by a classic colour-plus-alpha texture.