`grail.data.vbmfile` Module

Version: 16.2

Table of Contents

Overview
Examples
Functions
Constants

Overview

An ASCII VBM (Variable Block Model) file is used to store the vertices of 2D polylines. Multiple polylines can be stored in the same file. The VBM (ASCII) format consists of a header line with a plane number (usually the elevation or section line), a feature code to define the line, and optional orientation information. This is followed by a field of x, y points in free format:

2210.00 999
2480.80 4973.30
2457.50 4989.80
2460.40 5010.60
2463.40 5032.40
2472.20 5041.20
2495.70 5039.70
2515.70 5037.60
2536.70 5035.30
2562.50 5027.40
2589.50 5019.10
2605.90 5001.80
2622.20 4984.50
2639.40 4966.30
2639.40 4942.80
2625.10 4929.90
2610.10 4916.40
.0 .0
2225.00 999
2449.70 5038.20
2451.70 5041.50
2461.70 5052.20
2459.00 5055.80
2471.10 5080.90
2483.90 5107.20
2501.40 5125.40
2518.80 5143.60
2536.30 5161.80
2553.70 5180.00
2571.20 5198.20
.0 .0

Examples

The following snippet illustrates how to write to a VBM file:

from grail.data import vbmfile

path = "C:\\example.vbm"

polyline = [[0,0,0],[1,0,0],[1,1,0],[0,1,0],[0,0,0]]

#note that even though we only have one pointlist, we still must pass it in as a list of lists

myList = [polyline]

vbmfile.writeVBMFile(myList, path)

Functions

readVBMFile(path, orientation)

Opens a VBM file, parses the contents, returns a list of pointlists (one for each polyline contained in the file).

Arguments:

path : string

orientation : This value indicates on which plane the polyline exists (see constants)

Returns:

pointLists : a list of lists

writeVBMFile(pointLists, path)

Creates a regular SRV file. Note that if you only have one polyline to include, the function still expects a list containing the one point list.