Question: I want to animate several textures onto an object in a VET scene. What are my options for referencing the texture files?

Answer: If you want to animate different textures onto an object, you have 3 options for making the textures available.

Option 1 Keep the .jpg files external to the .mts file and assign the textures via the XML code in the .mtx file (see "Animate several external textures onto an object under the Example Files section).

This method works very well; however, there are two disadvantages when using this method. First, the file sizes are larger because you are unable to take advantage of Viewpoint?s Trixels NT wavelet compression, resulting in longer streaming times. Second, file management is more difficult due to the extra files to track.

Option 2 Create procedural planes in Scene Builder and apply textures to those planes. When you publish, the textures are compressed into the .mts file (see "Save textures to the .mts file & animate onto an object" under the Example Files section).

This technique has a few advantages. It makes full use of Viewpoint?s Trixels NT wavelet compression, resulting in faster streaming times. All the textures are in the .mts file, so file management is much easier. Since the planes that the extra textures are applied to are procedural, they do not increase the .mts file size. (Collapse the planes in the MTSInstance Tag, so that they do not show in the scene.)

The major disadvantage of this method is that one of the textures (typically the initial viewing texture) must be saved twice in the .mts file. First, the texture is applied to the target object. Then, a copy of the same texture (with a different file name) is applied to a procedural plane. This is necessary because when the first texture is streamed in, it is written to a memory address. When an animation applies a different texture to the initial texture, that memory address is overwritten with a new texture and the initial texture is lost. Having a second identical texture available allows you to repeatedly write a copy of the initial texture back into the initial texture?s memory address.

Using this method requires careful thought and planning of texture animations.

Option 3 Use a combination of these Options 1 and 2 (see "Animate a combination of external and internal textures onto an object" under the Example Files section.

This is also a good option. The initial texture is kept as a JPEG file outside of the .mts file and applied to the target object via the XML. Additional textures to be applied to the object are applied to procedural planes and published into the .mts file.

While there is at least one external JPEG file, this approach still allows for most of the textures to be compressed with Viewpoint?s Trixels NT wavelet compression, resulting in improved streaming times.

This method also avoids the memory address problems that occur under Option 2.

Summary
Options 1 and 3 are probably your best options for handling extra textures that your scene needs. Option 2 should be used only after you have carefully thought through the limitations imposed by the memory addressing issues.