Vizard 8 » Content Creation » Images » Images Introduction
8.1
Images are used to add color and other detail to model surfaces. The most common use of an image in modeling is for the diffuse texture (main color). They can also provide height information (bump map), transparency (alpha map), reflections (reflection map), and much more.
The image format you choose may affect the quality of the final rendered image in Vizard. The different formats use compression schemes that are either lossy (lose data) or lossless (save data). Lossy compression often results in smaller files. The downside is that image quality is permanently reduced. To reduce the file size, but retain the quality, compress the image using a lossless format. PNG, WEBP, TGA, and TIFF are examples of formats that support lossless compression.
When textures are loaded onto your graphics card, they are typically stored in an uncompressed state. Therefore, even though you have a 2048x2048 pixel image that is only a few hundred kilobytes as a JPEG (lossy), on the graphics card it will be 12 MB. An equivalent PNG image (lossless) will use up the same GPU memory (12MB) and be higher in quality.
Graphics card can only take advantage of a few specialized compression schemes. Vizard's Inspector tool can be used to convert textures to DXT or the supercompressed Basis Universal GPU texture format. The Basis Universal format is the recommended format and can provide much higher quality than DXT, while still providing a similar compression ratio. DXT compression can be applied to images through the OSG exporter, in the Vizard script, or with certain file formats (e.g. DDS). Since GPU texture compression is lossy, it will introduce some compression artifacts. For this reason, GPU texture compression is only recommended for resource intensive scenes, where uncompressed images could affect performance.
|
Format |
Extension(s) |
Compression |
Alpha |
Description |
|
JPEG |
.jpg, .jpeg |
Lossy |
No |
The best format for reducing file size in photographic images. |
|
Bitmap |
.bmp |
Uncompressed |
No |
Stores data for each pixel in the image without compression. |
|
TIFF |
.tif, .tiff |
Lossless |
Yes |
All the capabilities of Photoshop's native format, but with greater compatibility. |
|
GIF |
.gif |
Lossless |
Yes |
Typically used for small icons and animated images in Web pages. |
|
PNG |
.png |
Lossless |
Yes |
Most common lossless image format used in Web pages. |
|
TARGA |
.tga |
Lossless |
Yes |
Compression scheme works well for simple images. |
|
DDS |
.dds |
Lossy |
Yes |
Standard format for images with DXT compression. The type of alpha (none/sharp/gradient) depends on the DXT compression scheme. |
|
WEBP |
.webp |
Lossless and Lossy |
Yes |
WebP is a modern image format that provides superior lossless and lossy compression for images. It also supports animated images. |
|
Tool |
Description |
|
Adobe Photoshop |
Commercial software for professional graphics editing. |
|
GIMP |
Advanced image editor similar to Photoshop, but free and open source. |
|
Paint.NET |
Free image and photo editing software. Provides the essential tools and is easy to use. |