Fixing Incomplete BLP Lattice

TL;DR

Your BLP (Binary Large Object) lattice structure is missing top and bottom levels, causing issues with texture filtering or rendering. This guide shows you how to identify the problem and rebuild those levels using tools like TextureFinder or by manually editing the DDS file.

Understanding the Problem

BLP lattices are used in games (often older ones) for efficient texture storage. They consist of multiple mipmap levels, each progressively smaller than the last. The top level is the full-resolution texture, and the bottom level is a very small version. Missing these levels can lead to visual artifacts or crashes.

Solution Guide

1. Identify the Affected Texture(s)
   • Look for textures that appear blurry, distorted, or have strange colour issues in-game.
   • Check game logs or error reports; they might point to specific BLP files.
2. Verify Lattice Integrity with TextureFinder

   TextureFinder is a useful tool for examining BLP files.

   • Download and run TextureFinder.
   • Open the suspected BLP file in TextureFinder.
   • Examine the mipmap levels. If you see gaps at either end (missing level 0 or the highest numbered level), that confirms the problem.
3. Rebuild Missing Levels – Option 1: Using TextureFinder

   TextureFinder can automatically rebuild missing levels, but it’s not always perfect.

   • In TextureFinder, select “Tools” -> “Fix BLP”.
   • Choose the appropriate options. Generally, leaving the defaults is a good starting point.
   • Save the modified BLP file (make a backup first!).
   • Test in-game to see if the issue is resolved.
4. Rebuild Missing Levels – Option 2: Manual DDS Editing

   This method requires more technical knowledge but offers greater control.

   • You’ll need a DDS editing tool like Photoshop with the DDS plugin or DDS Tools.
   • Open the BLP file as a DDS texture in your editor. You may need to convert it first using a tool like BLP Converter.
   • Add the Top Level (Level 0): If missing, create a new image matching the original texture’s dimensions and copy the contents of the existing level 1 into it. Save as DDS with appropriate compression settings (DXT5 is common).
   • Add Bottom Levels: Repeatedly halve the width and height of an existing mipmap level to generate progressively smaller levels until you reach a very small size (e.g., 4×4 or 2×2 pixels). Save each new level as part of the DDS file.
5. Compression Settings

   Ensure your DDS files use the correct compression format for the game. DXT1, DXT3 and DXT5 are common choices.

   • Incorrect compression can cause visual artifacts or crashes. Consult game documentation or existing textures to determine the appropriate setting.
6. Testing

   After rebuilding levels, thoroughly test in-game to ensure the issue is resolved and no new problems have been introduced.