Difference between revisions of "STEP-NC WebGL Demo"

Revision as of 11:40, 15 February 2012

STEPTools Inc (Troy, NY) has developed a WebGL demonstration of standards-based display of CAD/CAM content over the web. The starting point is a STEP-NC file, conforming to Application Protocol 238 of the STEP standard for manufacturing data. A STEP-NC file contains information for computer aided manufacturing and may contain geometry for the workpiece at stages of the manufacture as well as geometry of the cutting tools, toolpaths, fixtures and machine centers, as well as process data.

• boxy.xml Warning 39 MB XML file.
• STEP-NC file This is a Zip archive of a STEP Part 28 (XML encoding) file.
• shell55130_tri.x3d Workpiece rendered through IndexedTriangleSet node , with per-triangle normals provided
• shell55130_tri_nonormal.x3d Workpiece rendered through IndexedTriangleSet node, without per-triangle normals included.
• shell55130_nurbs_transpose.x3d Workpiece rendered through NurbsTrimmedSurface, with parameters transposed for rendering on InstantReality X3d browser.

An XSLT script can generate an X3D file from the triangle data in WebGL data. The script used takes two parameters. Using the xsltproc XSLT command line tool, the invocation looks like:

xsltproc  -param "shape" "//shell[@id='id55130']" -param "include-normal" "false()"   convert_to_x3d.xsl boxy.xml > boxy_shell.x3d

<?xml version="1.0" encoding="utf-8"?>

'''XSLT script: convert_to_x3d.sxl'''
<!-- 
XSL transformation to generate an X3D file from the xml data used for 
the STEPTools WebGL demo (http://www.steptools.com/demos)

This transformation takes two parameters
shape : an XPath expression identifying the nodes in the source XML file which contains
geometry to be converted to X3D

include-normal : enter as true() or false()  whether normal geometry data taken from
source file should be included in X3D geometry

Copyright 2012 Vincent Marchetti

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.


-->



 
<xsl:stylesheet version="1.0" 
                xmlns:xsl="http://www.w3.org/1999/XSL/Transform" 
                xmlns:str="http://exslt.org/strings"
                extension-element-prefixes="str">

<xsl:output method="xml" encoding="utf-8"/>


<xsl:param name="shape"/>
<xsl:param name="include-normal" select="0"/>

<xsl:template match="/">
<X3D xmlns:xsd="http://www.w3.org/2001/XMLSchema-instance" 
    xsd:noNamespaceSchemaLocation="http://www.web3d.org/specifications/x3d-3.2.xsd" 
    version="3.2" 
    profile="Interchange">
  <head/>
  <Scene>
    <Background skyColor="0.2 0.5 0.2"/>
    <Shape>
    <xsl:apply-templates select="$shape"/>
    <Appearance>
        <Material containerField="material" diffuseColor="1.000000 1.000000 1.000000"/>
    </Appearance>
    </Shape>
</Scene>
</X3D>
</xsl:template>

<xsl:template match="shell">
<IndexedTriangleSet containerField="geometry" solid="FALSE">
    <xsl:attribute name="index">
    <xsl:for-each select="facets/f/@v">
        <xsl:for-each select="str:split(normalize-space(.))">
            <xsl:value-of select="number(./text())+0"/><xsl:text> </xsl:text>
        </xsl:for-each>
    </xsl:for-each>
    </xsl:attribute>
    <Coordinate containerField="coord">
    <xsl:attribute name="point">
    <xsl:for-each select="./verts/v/@p">
        <xsl:for-each select="str:split(normalize-space(.))">
            <xsl:value-of select="format-number(number(./text()),'###.####')"/><xsl:text> </xsl:text>
        </xsl:for-each>

        <xsl:if test="position() < last()">
            <xsl:text>, </xsl:text>
        </xsl:if>
    </xsl:for-each>
    </xsl:attribute>
    </Coordinate>
    
    <xsl:if test="$include-normal"> 
        <Normal containerField="normal">
        <xsl:attribute name="vector">
        <xsl:for-each select="facets/f/@fn">
            <xsl:for-each select="str:split(normalize-space(.))">
                <xsl:value-of select="format-number(number(./text()),'###.####')"/><xsl:text> </xsl:text>
            </xsl:for-each>
    
            <xsl:if test="position() < last()">
                <xsl:text>, </xsl:text>
            </xsl:if>
        </xsl:for-each>
        </xsl:attribute>
        </Normal>
    </xsl:if>
    
</IndexedTriangleSet>
</xsl:template>

</xsl:stylesheet>