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Web Integration > Download time and performance > About streaming
About streaming
You can make surface geometry, textures, and sounds streamable so that the web page can be displayed before all the 3D content is downloaded.
In the following illustration, Krazee Bob is in a room, pondering which door to open. Behind each door is a closet filled with junk about to fall on him. The surfer does not see this since the door has yet to be opened, so valuable time is being wasted by waiting for all this to download. This example explains the rationale behind streaming.
Without streaming, the 3D window would only appear once all the content (every object, every texture, every sound file) was downloaded. This could take some time-downloading content that is not even visible, sounds that may only be triggered a minute later by the surfer, textures on objects that you cannot see yet, and so on.
In the previous example, the default download behavior is the following:
The initial display time is 20 seconds. AXEL waits until all geometry, interaction, and animation is downloaded, and sends low-resolution versions of texture files. Then the page opens. As the surfer is watching or interacting, from second 20, sound files and full-resolution texture files will continue downloading. The download is complete at second 57.
The default may not be satisfactory. For example, you may want the wooden barrel texture on Krazee Bob to appear immediately at full resolution, while the car and all the junk behind the door stream in. You can change the default behavior by making specific objects streamable. You can also set the streaming priority to control which objects are streamed first.
To turn on streaming of geometry, textures, or sound files:
- In the World Explorer, expand and select the element you want to modify.
- In the Parameter Editor, turn on/off Streamable.
- Select the Streaming priority.
A low-resolution version of a streamed geometry (such as a null geometry) is inserted at the beginning of the axs stream. When the geometry is displayed in a web page, the low resolution geometry is downloaded first, then the real geometry is displayed as soon as it is downloaded.
Textures or sound files are streamable by default. If you want them to be downloaded immediately, turn off Streamable.
Geometry is not streamable by default. If you have a large object that does not appear immediately, you should turn on its Streamable parameter so that it does not hold up the display of your web page.
If you experiment with streaming, you will find that you can sometimes significantly reduce the initial display time by streaming parts of your World, especially textures and sounds. You can compare the download time estimates and the time at which they appear to the surfer (remember to choose which connection you are using in your Time Estimates).
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