1. DDS textures use less memory
The advantage of using .DDS textures for your materials is that this file type makes it possible to reduce the amount of memory that textures use by reducing the quality a little. This is useful if you're trying to cram as many textures as possible into a limited amount of graphics card and system memory, and is especially suitable for organic/nature textures where precision isn't vital.
- A 16-bit 1024x1024 .JPG image requires 2.4 MB of graphics card memory.
- The same image stored in .DDS format using BC7 compression would require only 630 KB. So you could use almost 4 x 1024x1024 .DDS textures for the 'price' of 1 .JPG texture.
You might notice that the DDS file size exceeds that of an equivalent .JPG file. The reason is that .JPG files are compressed files whereas .DDS files are compressed in the graphics card memory, so you can safely ignore the .DDS file sizes.
.DDS files use 'lossy' compression which means that you will lose detail and color information compared to your original texture.
Lumion 6.5 and newer support .DDS BC7 format which is compressed at a ratio of 1:4 in the graphics card memory. Despite the compression, the quality is still excellent.
Lumion 6.3 and older support .DDS DXT1/3/5 formats and the compression reduces the quality significantly. Click here to see which of the DXT formats to use when saving .DDS textures.
2. Lumion 6.5 and newer
2.1: To save a .DDS BC7 texture, you'll need to install the Intelworks DDS plug-in for Adobe Photoshop.
2.2: If your texture contains an alpha channel, it's very important that there is a Background layer in the Photoshop file before you save the .DDS BC7 texture - otherwise, the exporter will skip the alpha channel.
2.2: Please note that the length and width of DDS textures have to be a power of two, e.g. 8x8 pixels, 16x16, 32x32, 64x64, 128x128, 256x256, 512x512, 1024x1024, 2048x2048, 4096x4096 and so on.
3. Lumion 6.3 and older
3.1: If you want to save .DDS textures for your Lumion materials, please note that you'll need Adobe Photoshop and Nvidia's DDS plugin for Photoshop.
3.2: Please note that DDS textures have to be a power of two, e.g. 8x8 pixels, 16x16, 32x32, 64x64, 128x128, 256x256, 512x512, 1024x1024, 2048x2048, 4096x4096 and so on.