Ventuz Blog

Receiving video streams in Ventuz seems always to be a kind of mystery.
The existence of Windows ME II (aka Vista) doesn’t make things any better!
Recently a customer was struggling with streaming again so I decided to write this blog entry.
This is not meant as a complete specification – it´s more a collections of hints.

Generaly Ventuz supports video input stream via DirectShow. QuickTime streaming is not supported yet!
The stream ULR has to be specified in the File property of the Movie Clip node.
There are three protocols which can be used under XP: MMS, HTTP and UDP
MMS and HTTP should work without any additional efforts. A codec which is definitely working is WMV.
To stream MPEG2 via UDP you need e.g.:
http://www.elecard.com/products/products-pc/consumer/mpeg2-plugin-wmp/

Under Vista/ Win 7  MMS does not work because of:
http://blogs.msdn.com/mediasdkstuff/archive/2009/02/05/rendering-a-url-with-graphedit.aspx
Some MMS Urls can be rendered anyhow if you change the protocol of the Url from MMS to HTTP:
mms://steaming_url… -> http://steaming_url…

People asking how to address data files like Excel Sheets, Movies and Images from Ventuz if they are not included inside the VPR presentation file. The common solution is to create a absolute folder on a certain location where these files resist (like C:\Data) and address them by an abosule file-reference URL.

There is a much more comfortable way to do this. Use relative paths.
A relative path is not defined by the standard file-URL scheme, but many application (as well Ventuz) created their own representation of a relative file-URL.

To use it, you need to utilize the URL node of Ventuz and set the scheme to “FILE”.
Make the resulting URL a relative path by putting a leading dot-slash before the actual filename.
All other settings of the URL node can be ignored.

"./data.xlsx"
"./subfolder/data.xlsx"

The resulting path is always relative to the current project:

• In Ventuz Designer the folder where the project file (.vzp) is located
• In Ventuz Presenter its the location of the presentation (.vpr) has been started
• In Ventuz Presenter/Runtime Director mode the location of the actual Director file (.vzd)

Download a mini-example for this here

A lot of people use a Glow layer in their Ventuz scenes to give objects a shiny look.
But they usually pass the complete object through the glow shader. This results in unnatural light effects which does not correspond to the laws of shading.
Actually a glow effect should only occure in the area of specular highlights.
Attached is scene which demonstrates a specular glow.  The drawback of this rendering technique is that an additional rendertarget is needed.

The Ventuz scene is here:
SpecularGlow.zip