3SPACER©

FastSCANTM

Stylus

February 2004

Copyright c© 1998–2004 by PolhemusColchester, Vermont USA

All rights reserved. No part of this publication may be reproduced, stored in a re-trieval system, or transmitted, in any form or by any means, mechanical, photocopy-ing, recording or otherwise, without the prior written permission of Polhemus. Nopatent liability is assumed with respect to the use of the information contained herein.While every precaution has been taken in the preparation of this manual, Polhemusassumes no responsibility for errors or omissions. Neither is any liability assumedfor damages resulting from use of the information contained herein.

3SPACE R© is a registered trademark of Polhemus.

FastSCAN Stylus i

FCC STATEMENT

This equipment has been tested and found to comply with the limits for a Class Adigital device, pursuant to part 15 of the FCC Rules. These limits are designed toprovide reasonable protection against interference when the equipment is operatedin a commercial environment. This equipment generates, uses, and can radiate radiofrequency energy and, if not installed and used in accordance with the instructionmanual, may cause interference to radio communications. Operation of this equip-ment in a residential area is likely to cause interference, in which case the user will berequired to correct the interference at his own expense.

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Contents

1 Introduction 11.1 Stylus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.2 Laser Pointer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

2 Setup 32.1 Stylus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32.2 Laser Pointer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

3 Capturing Points 4

4 Capturing Lines 6

5 Exporting 95.1 Export Stylus Points Dialog Box . . . . . . . . . . . . . . . . . . . . . . . 95.2 CSV Export Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105.3 ASCII Export Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

6 Limited Warranty and Limitation of Liability 12

7 Indemnity Against Patent Infringement 14

8 Customer Service 15

FastSCAN Stylus 1

1 Introduction

Many applications require localization of discrete points on a 3D surface, in additionto the captured 3D surface itself. This can be done using a point digitizer. Two differentmethods of point localization have been integrated into FastSCAN:

1. An electromagnetic stylus.

2. An optical laser pointer (or optical stylus).

In both instances, the digitized points ± orientations can be saved to a separate file,or in some instances, integrated into export file formats, e.g. AAOP.

1.1 Stylus

The FastSCAN stylus is shown in Figure 1. It contains an electromagnetic tracker, andthe location and orientation of the stylus tip is recorded whenever the stylus buttonis depressed.

Note that the FastSCAN stylus plugs into the ‘Reference’ port of the PU, and thereforethe system cannot be used in Receiver is Reference mode.

The stylus is an optional extra, and can be purchased at any time from your distribu-tor. The stylus implementation will work immediately with the slimline PU, shippingsince October 2002, and FastSCAN software version 3.6.0 or later. Older PUs can bemodified to enable stylus functionality for a fee – contact techsupport@polhemus.comto inquire about modification details.

Figure 1: The FastSCAN stylus.

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1.2 Laser Pointer

Use of the optional shutter turns your FastSCAN into a point digitizer, or ‘opticalstylus’, as shown in Figure 2.

The hinged shutter is swung down when you are in laser pointer mode and changesthe laser line into a point. The location of the point on the object’s surface, and theorientation of the Wand is recorded whenever the Wand trigger is depressed when inlaser pointer mode.

The FastSCAN shutter can be purchased at any time from your distributor. Unlikethe (electromagnetic) stylus, the optical stylus requires an additional license to beinstalled.

(a) (b)

Figure 2: The optical stylus shutter, with the shutter positioned for laser pointer mode(a), and the shutter positioned for normal scanning mode (b).

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2 Setup

2.1 Stylus

To setup the stylus, follow the instructions below.

1. Switch the PU off, connect the stylus to the reference receiver port, then switchthe PU back on.

2. Ensure Scanner / Transmitter is Reference is checked.

3. Pull the Wand trigger, and you will be prompted to point the Wand at the Trans-mitter and pull the trigger, in the usual way.

4. Scan the object.

5. When you are ready to use the stylus, first press the stylus button once, andyou will be prompted to setup the stylus hemisphere, in a manner analogous tosetting up the Wand; namely, when directed, point the stylus at the Transmitterand push the stylus button.

6. You may now use the stylus.

If the above steps are not followed correctly resulting in incorrect stylus hemispheresetup, chose Stylus / Reset Hemisphere to repeat Step 5 above.

2.2 Laser Pointer

To use the FastSCAN Cobra as a laser pointer, follow the instructions below.

1. Scan the object.

2. When you are ready to collect points or lines, put the optical stylus shutter intothe down position as shown in Figure 2(a).

3. The software is put into laser pointer mode in one of the following ways:

• Click on the Laser Pointer Mode icon ( ) on the button bar. Note that thisicon is only present when the correct license has been installed and once theFastSCAN software has been correctly initialized.

• Click on ’P’ or ’L’ keys to start Laser Pointer Mode in point capture or linecapture mode respectively, as explained below.

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3 Capturing Points

Once setup, each depression of the stylus button (or Wand trigger) generates a posi-tion and orientation output within the tracker’s spatial system. The FastSCAN soft-ware records these co-ordinates and displays them on screen. This assumes of coursethat the stylus (or Wand) is somewhere within the trackers range. Normally, thesemarkers would be somewhere on the surface of the object being scanned, althoughthis is not necessarily a constraint in the case of the electromagnetic stylus.

Figure 3 shows a number of markers that were applied to the scanned surface of amannequin.

(a) Raw surface (b) Processed surface (c) Close-up

Figure 3: The makers on the raw data (a), the same markers shown in the processedsurface (b), and close-up in (c).

Figure 3(c) shows a close-up of the mannequin’s right ear with two markers present.The markers take the form of cones, providing an indication of the exact position andorientation of the stylus1 when at the marked point. Other marker shapes are alsoavailable, via the Stylus / Properties menu.

The Stylus List dialog box can be used to manipulate the points and lines (capturinglines is described in a subsequent section) collected with the stylus. The Stylus Listdialog box is shown in Figure 4, and is opened via the Stylus / Stylus List menu.

1For the remainder of this document, the term ‘stylus’ will be used to refer to either the electromagneticstylus or the optical stylus.

FastSCAN Stylus 5

To highlight a point, click on the list item. The color of the sweep in the main windowwill be changed to the preview color (normally red). To hide a point or line, click onthe check-mark to the left of the list item. Hidden points or lines are not saved whenthe data is exported, but all points or lines, visible or not, are saved when you savethe Raw Data in the HLS format.

The Move to Surface button is used to drop points onto the closest part of the surface.This is useful as if the stylus point is required to lie exactly on the surface. Highlightthe stylus point and click on the Move to Surface button. The point will move tothe closest part of the surface that is within range. If no part of the surface is withinrange then the point will not be moved. The range is set using the entry box besidethe button. If a stylus point has been moved to the surface, the stylus list will displaya different icon, namely change from the icon to the icon, and the distance it wasmoved is displayed in the second column. The Raw and Export Surfaces are notexactly the same, so points may move to slightly different places on each surface.

Figure 4: The Stylus List dialog box.

Once the Stylus List dialog box is open, you can manipulate the selection and pointvisibility via keyboard shortcuts. Press { and } (curly braces) to move the selectionup and down, and press " (double quote) to toggle the visibility of the selected styluspoint. You can also remove the last added stylus point using the Undo Stylus Markitem in the Stylus menu.

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4 Capturing Lines

When in “Line” mode you can mark lines in the tracker’s spatial system by pressingand holding the stylus button/trigger while moving it. Each line is made up of aseries of samples, joined by line segments. You can adjust the minimum line segmentsize, so that FastSCAN will only record a new sample when the stylus has movedat least that distance from the previous sample. When accuracy is important, use asmall line segment size (such as 1mm). When you want fewer points in total (anddon’t mind the loss of detail), increase the line segment size. If you move the stylusquickly then line segments may be larger than your specified minimum size.

To change to “Line” capture mode, select the Stylus / Properties menu item, andclick on the Capture Lines option, as shown in Figure 5. To change the minimum linesegment size, edit the Line Segment Size value, also in the Stylus Properties dialogbox. You can use both “Point” and “Line” modes, and use different line segmentsizes, in the same scan.

Figure 5: The Stylus Properties dialog box.

Once in “Line” mode, capture a line as follows:

1. Place the stylus tip (or laser point) where you want to start, as shown in Fig-ure 6(a).

2. Press and hold the stylus button (or Wand trigger). In the case of the electro-magnetic stylus, it is important to firmly hold down the stylus button to ensurethat continuous connection of the button contacts is maintained.

3. Move the stylus tip along the path or line that you want to capture.

4. When you have reached the end of your line, release the stylus button/trigger.

The display of stylus points and lines is also controlled via the Stylus Propertiesdialog box, by selecting from from the drop-down boxes in the lower half of the dialog

FastSCAN Stylus 7

box. You can also remove the last added stylus line using the Undo Stylus Mark itemin the Stylus menu.

Lines are displayed as a wide, solid line with ’hairs’ at each sample, as shown inFigure 6(b). The hairs represent the position and orientation of the stylus at thatsample. As shown in Figure 6(c), the Stylus List dialog box lists both lines and points,using the icon for lines, and for lines that have been moved to the surface.

When a line is moved to the surface, only those samples that are close enough tothe surface are moved. This may create discontinuities where the line moves off thesurface, as shown in Figure 7. If some samples are not moved, increase the maximummove distance. Even if not all samples are moved, the line will still be marked asbeing on the surface; to recalculate its position switch Move to Surface off then onagain. Lines containing a large number of sample points may take some time to move.

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(a) Line capture. (b) The resulting scan.

(c) Lines in stylus list.

Figure 6: Using the stylus to capture a line from an object.

FastSCAN Stylus 9

Figure 7: A line moved partially onto the surface.

5 Exporting

All stylus data is saved along with the raw data at the time when the HLS file is saved.Additionally, in some instances, is is integrated into export file formats, e.g. AAOP.The stylus data may also be exported independently of the scanner data, and is doneas a separate step, which is described in the following sections.

5.1 Export Stylus Points Dialog Box

To save stylus locations, select File / Export / Stylus Points, although the FastSCANsoftware will ask if you want to save stylus data whenever you export a surface. Ifyou have moved some stylus points to the surface then the on-surface locations willbe saved, not the original locations.

The Export Stylus Points dialog box is shown in Figure 8. The marker data can be ex-ported as ASCII text (.TXT) or Comma Separated Values (.CSV). Just as for exportingsurfaces, you can export stylus data in either the Screen View or Tracker Referencecoordinate systems. You can also choose between four data types to control whatdata is saved:

Points saves just the x, y and z values.

Points + Normals also saves the stylus orientation as three elements dx, dy and dz ofa vector pointing in the same direction as the stylus.

Points + Eulers saves the orientation of the stylus as three Euler angles.

4× 4 Matrix saves the complete orientation matrix of the stylus, in row-major order(the first four numbers are the first row, the next four the second row, and so

10 FastSCAN Stylus

on).

Figure 8: Export Stylus Points dialog box.

5.2 CSV Export Format

CSV (Comma Separated Values) is a simple, portable spreadsheet format. You shouldbe able to load it with any common spreadsheet. The CSV export format contains onerow for each sample. Hidden points and lines will not be included. A point is a singlesample; a line is a series of samples. The columns in the file depend on the Data Typethat you export. The columns in common are:

item The item number of the point or line. Each point, and the whole of each line,counts as a single item.

line index If the sample is a line, the index of that sample in the line. Blank if thesample is a point.

x, y, z Location of the sample.

on surface “TRUE” if the sample has been moved to the surface, “FALSE” otherwise.

The ”Points + Normals” data type adds:

FastSCAN Stylus 11

dx, dy, dz The vector giving the direction that the stylus was pointing for the sample.

The ”Points + Eulers” data type adds:

alpha, beta, gamma The Euler angles giving the direction that the stylus was point-ing for the sample.

The “4× 4 Matrix” data type gives the 16-element orientation matrix of the stylus (inrow major order). The sample location (the x, y and z columns) is part of this matrix.

Figure 9 shows a sample CSV export using “Points” data type, containing two points(items 2 and 3) and part of a line (item 5), when loaded into Excel.

Figure 9: A CSV export file loaded into Excel.

5.3 ASCII Export Format

The ASCII export format is similar to, but simpler than the CSV format. It uses white-space separated fields and comment lines start with ‘%’. The columns ‘item’, ‘lineindex’ and ‘on surface’ are not included; only data columns are listed. There is noway to determine whether a sample is on the surface or part of a line. When youdon’t need this extra information, the ASCII format may be easier to use, otherwiseuse the CSV format.

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6 Limited Warranty and Limitation of Liability

6.1

Polhemus warrants that the Systems shall be free from defects in material and work-manship for a period of one year from the date ownership of the System passed fromPolhemus to Buyer. Polhemus shall, upon notification within the warranty period,correct such defects by repair or replacement with a like serviceable item at Polhe-mus’ option. This warranty shall be considered void if the System is operated otherthan in accordance with the instructions in Polhemus’ User Manual or is damaged byaccident or mishandling. Parts or material which are clearly expendable or subjectto normal wear beyond usefulness within the warranty period such as lamps, fuses,etc., are not covered by this warranty.

6.2

In the event any System or portion thereof is defective, Buyer shall, within the war-ranty period, notify Polhemus in writing of the nature of the defect, remove the de-fective parts and, at the direction of Polhemus Customer Service, ship such parts toPolhemus. Upon determination by Polhemus that the parts or Systems are defectiveand covered by the warranty set forth above, Polhemus, at its option shall repair orreplace the same without cost to Buyer. Buyer shall pay all charges for transporta-tion and delivery costs to Polhemus’ factory for defective parts where directed to besent to Polhemus, and Polhemus shall pay for transportation costs to Buyer’s facilityonly for warranty replacement parts and Systems. Removed parts covered by claimsunder this warranty shall become the property of Polhemus.

6.3

In the event that allegedly defective parts are found not to be defective, or not cov-ered by warranty, Buyer agrees that Polhemus may invoice Buyer for all reasonableexpenses incurred in inspecting, testing, repairing and returning the Systems and thatBuyer will pay such costs on being invoiced therefor. Buyer shall bear the risk of lossor damage during transit in all cases.

6.4

Any repaired or replaced part or System shall be warranted for the remaining periodof the original warranty or thirty (30) days, whichever is longer.

FastSCAN Stylus 13

6.5

Warranties shall not apply to any Systems which have been:

(a) repaired or altered other than by Polhemus, except when so authorized in writingby Polhemus.

(b) used in an unauthorized or improper manner, or without following normal oper-ating procedures; or

(c) improperly maintained and where such activities in Polhemus’ sole judgement,have adversely affected the Systems. Neither shall warranties apply in the caseof damage through accidents or acts of nature such as flood, earthquake, light-ning, tornado, typhoon, power surge or failure, environmental extremes or otherexternal causes.

6.6

POLHEMUS DOES NOT WARRANT AND SPECIFICALLY DISCLAIMS THE WAR-RANTY OF MERCHANTABILITY OF THE PRODUCTS OR THE WARRANTY OFFITNESS OF THE PRODUCTS FOR ANY PARTICULAR PURPOSE. POLHEMUSMAKES NO WARRANTIES, EXPRESS OR IMPLIED, EXCEPT OF TITLE ANDAGAINST PATENT INFRINGEMENT, OTHER THAN THOSE SPECIFICALLY SETFORTH HEREIN.

6.7

IN NO EVENT SHALL POLHEMUS BE LIABLE UNDER ANY CIRCUMSTANCESFOR SPECIAL INCIDENTAL OR CONSEQUENTIAL DAMAGES, INCLUDING,BUT NOT LIMITED TO LOSS OF PROFITS OR REVENUE. WITHOUT LIMIT-ING THE FOREGOING POLHEMUS’ MAXIMUM LIABILITY FOR DAMAGES FORANY CAUSE WHATSOEVER, EXCLUSIVE OF CLAIMS FOR PATENT INFRINGE-MENT AND REGARDLESS OF THE FORM OF THE ACTION (INCLUDING BUTNOT LIMITED TO CONTRACT NEGLIGENCE OR STRICT LIABILITY) SHALLBE LIMITED TO BUYER’S ACTUAL DIRECT DAMAGES, NOT TO EXCEED THEPRICE OF THE GOODS UPON WHICH SUCH LIABILITY IS BASED.

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7 Indemnity Against Patent Infringement

Polhemus shall have the right at its own expense, to defend or at its option to settle,any claim, suit or proceeding brought against Buyer on the issue of infringement ofany United States patent by any product, or any part thereof, supplied by Polhemusto Buyer under this Agreement. Polhemus shall pay, subject to the limitations here-inafter set forth in this paragraph, any final judgement entered against Buyer on suchissue in any such suit or proceeding defended by Polhemus. Polhemus at its soleoption shall be relieved of the foregoing obligations unless Buyer notified Polhemuspromptly in writing of any such claim, suit or proceedings, and at Polhemus’ expense,gave Polhemus proper and full information and assistance to settle and/or defendany such claim, suit or proceeding. If the product, or any part thereof, furnished byPolhemus to Buyer becomes, or in the opinion of Polhemus may become, the subjectof any claim, suit or proceeding for infringement of any United States patent, or in theevent of an adjudication that such product or part infringes any United States patent,or if the use, lease or sale of such product or part is enjoined, Polhemus may, at itsoption and its expense: (a) procure for Buyer the right under such patent to use, leaseor sell, as appropriate, such product or part, or (b) replace such product or part, or(c) modify such product, or part, or (d) remove such product or part and refund theaggregate payments and transportation costs paid therefore by the Buyer less a rea-sonable sum for use, damage and obsolescence. Polhemus shall have no liability forany infringement arising from: (i) the combination of such product or part with anyother product or part whether or not furnished to Buyer by Polhemus, or (ii) the mod-ification of such product or part unless such modification was made by Polhemus, or(iii) the use of such product or part in practicing any process, or (iv) the furnishingto Buyer of any information, data, service or application assistance. Buyer shall holdPolhemus harmless against any expense, judgement or loss for infringement of anyUnited States patents or trademarks which results from Polhemus’ compliance withBuyer’s designs, specifications or instructions. Polhemus shall not be liable for anycosts or expense incurred without Polhemus’ written authorization and in no eventshall Polhemus’ total liability to Buyer under, or as a result of compliance with, theprovisions of this paragraph exceed the aggregate sum paid to Polhemus by Buyerfor the allegedly infringing product or part, exclusive of any refund under option (4)above. The foregoing states the entire liability of Polhemus, and the exclusive remedyof Buyer, with respect to any actual or alleged patent infringement by such productor part.

FastSCAN Stylus 15

8 Customer Service

If you encounter any problems with your FastSCAN instrument, help is just a tele-phone call away. Call 802/655-3159 (800/357-4777 U.S. and Canada) and ask for Cus-tomer Service. For the most part, our Customer Service engineers can handle yourproblems over the telephone and get you back into the fast lane right away. If theproblem requires repair of your instrument, the Customer Service engineer will issueyou a Return Merchandise Authorization (RMA) number. Polhemus strongly sug-gests retaining the original shipping container for your FastSCAN instrument in theevent that the instrument may require repair. Please do not return any instrumentwithout an RMA number, as it will not be accepted. If your instrument is still underwarranty, Polhemus will repair it free of charge according to the provisions of thewarranty as stated in Section 6 of this document. The proper return shipping addressis:

Polhemus40 Hercules DriveColchester, Vermont 05446

Telephone (voice): (802) 655-3159Toll Free (USA & Canada): (800) 357-4777Telephone (FAX): (802) 655-1439Email: techsupport@polhemus.com

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P.O. BOX 560, 40 HERCULES DRIVECOLCHESTER, VT 05446

802/655-3159FAX: 802/655-1439

USA & CANADA: 1-800/357-4777

http://www.polhemus.com/