XB PointStream/extending xbps

Extending XB PointStream

Using the internal XB PointStream parser and shader

If you decide to use the internal XB PointStream parser and shader, you can have a script displaying your point cloud in about 10 lines of JavaScript. However, you will be required to send in your point cloud as an .ASC file as that is the only format we currently support. Also, the built-in shader will only draw the minimum necessary for you point cloud. That is, it will only render vertex positions and colors.

Using the internal XB PointStream parser with a custom shader

It is possible to create shader effects on point cloud objects to add effect such as mirroring, etc.

If you decide to use the internal .ASC parser and write a custom shader, you'll need to ensure your vertex shader uses the correct uniform and attribute variable names which XB PointStream refers to.

The built-in .ASC parser only reads in vertex position and colors, so you must use the following names to refer to those attributes in your vertex shader:

vec3 ps_Vertex vec4 ps_Color

XB PointStream will refer to the following uniforms:

For transformations: mat4 ps_ModelViewMatrix mat4 ps_ProjectionMatrix

For point size: float ps_PointSize vec3 ps_Attenuation

Using the internal XB PointStream shader with a custom parser

If your point cloud is in a format other than .ASC, but you want to use the built-in shader, you'll need to make sure your parser writes to the correct attribute names

insert URL to example*

"ps_Vertex" "ps_Color"

Your script must also register your parser with XB PointStream with: ps.registerParser("XYZ", Your_XYZ_Parser_Name);

Using a custom shader and parser