Present3D Help

P3D solutions for current problems

Alpha

1) to enable alpha channels for an image or movie, you need to set the fade to a value less than 1 so:

fade="0 0.999"

<!-- nebula movie -->
<slide>
<duration>25.0</duration>
<background></background>
<title></title>
<layer>
<model coordinate_frame="slide" scale="250" position="0.5 0.5 0" fade="0 0  1 1" rotate="60 1 0 0">starfield2.osg</model>
<stereo_pair fade="0 0.999" position="0.5 0.5 0" rotate="0.01 1 0 0"  scale="1">
<image_left   region="0.0 0.0 0.5 1.0" >stereoMovies/nebulaLA0.5.mov</image_left>
<image_right          region="0.5 0.0 1.0 1.0" >stereoMovies/nebulaLA0.5.mov</image_right>
</stereo_pair>
</layer>
</slide>

.

Transparency problem solutions for models with textures with alpha channel.

This applies to movie to or single file textures with alpha channel.  Generally alpha textures look blocky or flicker.  To get round this the model file must be converted to .osg file and edited. Below is example of requires information in osg file:

Geometry {

      DataVariance DYNAMIC

      StateSet {

        UniqueID StateSet_0

        DataVariance STATIC

        rendering_hint TRANSPARENT_BIN

        renderBinMode USE

        binNumber 10

        binName DepthSortedBin

        GL_CULL_FACE ON

        GL_LIGHTING ON

        GL_BLEND ON

        Material {

          DataVariance STATIC

          ColorMode OFF

          ambientColor 0 0 0 1

          diffuseColor 0.8 0.8 0.8 1

          specularColor 0.5 0.5 0.5 1

          emissionColor 0 0 0 1

          shininess 64

        }

        BlendFunc {

          DataVariance STATIC

          source SRC_ALPHA

          destination ONE_MINUS_SRC_ALPHA

        }

        textureUnit 0 {

          GL_TEXTURE_2D ON

          Texture2D {

            DataVariance STATIC

            file "radio.mov"

The entries in purple relate to transparency settings.  If you convert from .flt file using osgconv most of the values should be correct except GL_CULL_FACE OFF needs to be converted to ON.  If the .osg file is converted from a different format  eg .obj or via blender more of the settings may need to be changed.

2) a recent issue with movies with alpha has been solved by introducing a small rotate to the movie :

rotate="0.01 1 0 0"

but it only works, with the rotation in the x as above, see above example also.

Rotation of models on import using osgconv or rot plugin

osgconv

-o orientation     - Convert geometry from input files to output files.
Format of orientation argument must be the following: 
X1,Y1,Z1-X2,Y2,Z2
or
degrees-A0,A1,A2
where X1,Y1,Z1 represent the UP vector in the input
files and X2,Y2,Z2 represent the UP vector of the
output file, or degrees is the rotation angle in degrees
around axis (A0,A1,A2).  For example, to convert a model 
built in a Y-Up coordinate system to a model with a Z-up
coordinate system, the argument may look like
0,1,0-0,0,1
or 
-90-1,0,0

.

An example of it in action is a rotation of 90 degrees about the z axis:

osgconv cow.osg -o 90-0,0,1 test.osg

For Maya models you'll want something like:

osgconv cow.osg -o 90-1,0,0 test.osg

rot psuedo plugin

There is also the rot psuedo plugin which you can use like:

osgviewer cow.osg.90,0,0.rot

Which does a rotation by 90 degrees about the x axis. The parameters are rotation-X, rotation-Y, rotation-Z.

You'll be able to us the rot plugin in conjunction with the P3D xml file format, so instread of references cow.osg you just reference cow.osg.90,0,0.rot. The nice thing about this is you don't need to modify the file itself.

Applying a Movie to a Model:

Convert the .obj file to a .osg by using the osgconv function:

%osgconv file.obj file.osg

now open the file.osg file in BBEDIT and search for - file "picture.jpg" or, file "picture.png" if using alpha channels, and replace with full path to .mov file that you want use.

Note that movies need to be flipped horizontally and vertically to appear correctly - this can be done in Quicktime.

LWS file format

http://www.newtek.com/products/lightwave/developer/LW80/8lwsdk/docs/filefmts/lwsc.html

To remove unwanted animation from a .lws file create a .osg file by using osgconv :

$ osgconv file.lws file.osg

Then open the osg file in BBEDIT and search for :

this will probably be set to 1

use the replace all function to change all to :