Quit Gambling with Huge Files! Scott McEachron DC CADD (Dallas, TX)

Transcription

1 November 30 December 3, 2004 Las Vegas, Nevada Quit Gambling with Huge Files! Scott McEachron DC CADD (Dallas, TX GI33-2 Ever import a 250MB ESRI Shape file or a 3GB aerial image? We'll show you how to use the tools in Autodesk Land Desktop and Autodesk Map to handle files of such enormous size, yet still add manageable character to your mapping and design projects. About the Speaker: For the past 6 years, Scott has taught subdivision/site design using Autodesk products to users nationwide at federal, state, and local agencies in both the public and private sectors. As a Solutions Specialist with DC CADD in Dallas, TX, Scott has built his reputation by offering real-world solutions to everyday civil/survey issues, and is considered a leader in the field. He has written courseware and published several documents, tips, and tricks featured on TenLinks.com as well as other websites.

2 Outline Hardware recommendations Software recommendations System variables Application ID table Ballooning drawings Drawing cleanup using Autodesk MAP Recovering damaged drawings Hardware Recommendations Dual Processors AutoCAD is simply a complex mathematical program. With dual processors, you ll notice just a 2-4% increase in performance over a single processor. When cost is a consideration, your best bet is still a single processor running at least 2.4 GHz. If your work requires a lot of imagery, a dual processor may work well for you. I run dual P4 s at 3.2 GHz on my laptop and my files range in size from 10 to 100Mb. I don t notice much lag time when modeling complex corridors in Civil3D. Video Card NVidia or ATI. Both companies have a proven history with Autodesk products; accept nothing less. I run an ATI Mobility Radeon 9700 with 128Mb RAM on-board; you can t go wrong with 128Mb and the card will last as long as the system. If you decide an ATI card meets your needs in terms of cost and performance, disable the PowerPlay option. PowerPlay has a tendency to have a negative effect on an AutoCAD when working in 3D (Orbiting. With Powerplay turned on, I notice a significant decrease in performance in AutoCAD

3 I also recommend setting your video adapter for high performance as opposed to high quality. Video cards have come a long way; you won t sacrifice quality when setting an adapter for performance. RAM 2 GHz, can t beat it and the system will remain strong as new and /or updated software is released. If price is a consideration, get at least 1GHz. 3

4 Software Recommendations Operating System WindowsXP Professional it s made to run on workstations. Depending upon your IT structure, you ll want to keep XP updated by visiting windowsupdate.microsoft.com on a regular basis. I have WindowsXP Service Pack 2 and have no issues running Autodesk 2005 products. AutoCAD Updates and Service Packs Stay in touch with Autodesk on the WWW. Some of the most common AutoCAD problems are resolved simply by applying a service pack. I still get calls from users having difficulty plotting to the HP 1050C from Model Space. A service pack was released to resolve the issue almost 2 months ago. Keep your software updated; keep your hardware drivers updated. AntiVirus Software I ve been running Norton Anti-Virus alongside AutoCAD as long as I can remember, and I ve never had an issue with system performance; but I ve done some things to keep the two programs from conflicting: Enable Auto-Protect, but don t scan the AutoCAD files, including the files stored in the user profile as well as the Common Shared Files. 4

5 Run Auto-Update in the background, or update your Anti-Virus files regularly. Norton AntiVirus can be purchased via the web for $50 a small price to pay to protect your valuable data. 5

6 Defragment Your filing cabinet at the office is a mess. It s difficult to find files EVEN if you know what drawer they re in. Your hard drive is no different keep it clean. You can use either the Windows defrag utility or various third-party packages. PerfectDisk and DisKeeper have consistently high ratings. I ve used them all, but in the end settled for the Windows defragmenter. System Variables ISAVEPERCENT The ISAVEPERCENT system variable controls the amount of wasted space tolerated in a drawing file. The default value of 50 means the wasted space within the file will not exceed 50 percent of the total file size. Wasted space is eliminated by periodic full saves, but by setting the variable to zero, the system forces a full save, with no wasted space, each time a drawing is saved. By limiting wasted space, a more stable drawing file is created. Increasing the value of the ISAVEPERCENT system variable decreases the amount of time used to save a drawing by allowing a greater amount of wasted space in the drawing. This usually results in a larger size for the drawing file. Decreasing the value of the ISAVEPERCENT system variable often results in a smaller file size and can decrease the amount of time it takes to open a drawing. However, save operations may be slower. In a 100Mb file, I notice little difference. 6

7 CRC Validation CRC Validation specifies whether a cyclic redundancy check (CRC will be performed each time an object is read into the drawing. CRC is an error-checking mechanism. If drawings are being corrupted and hardware problems or AutoCAD errors are suspected, turn this option on, and read/write errors will automatically be corrected when opening/saving files. It may have a slight performance impact on larger files. But, over time it stands a good chance of correcting problems on the fly without user interaction. Audit your work Computer hardware problems, power surges, user mistakes, or software problems can cause errors that prevent you from editing or plotting the drawing. By saving and AUDITing your work regularly, you can ensure a minimum of lost data if your system fails. For easy access, AUDIT places all objects for which it reports errors in the Previous selection set. However, editing commands affect only the objects that belong to the current paper space or model space. If you set the AUDITCTL system variable to 1, AUDIT creates an ASCII file describing problems and the action taken and places this report in the same directory as the current drawing, with the file extension.adt. Application ID Table Ballooning Drawings RegApps Some major programs on the market (not Land Desktop, not Civil3D, not Microstation have a tendency to save a registered application with an invalid name, such as "##*a%"?s*" in an AutoCAD drawing file. Anytime this drawing is used, even as an xref, new "##*a%"?s*" RegApp entries will be added to the drawing referencing it, as AutoCAD doesn't recognize that "##*a%"?s*" is already registered in the current drawing; a "virus" is born. Invalid RegApp entries will balloon a drawing over time, Audit will report no errors, but at some point, the drawing will no longer open. If you have a file where the visual content doesn't justify the file size and it seems to be getting progressively worse, you can check if the "bloating" is indeed caused by this virus by doing the following test: 7

8 Issue the following command at the AutoCAD command prompt: (tblnext "appid" 5(while (print (tblnext "appid" If this action produces a similar listing to the one below (often scrolling infinitely, you need to clean the infected drawing: ((0. "APPID" (2. "ACAD" (70. 0 ((0. "APPID" (2. "RAK" (70. 0 ((0. "APPID" (2. "ADE" (70. 0 If you enter -purge at the Command prompt, -PURGE displays the following prompt on the command line: Enter type of unused objects to purge: [Blocks/Dimstyles/LAyers/LTypes/Plotstyles/SHapes/textSTyles/Mlinestyles/Tablestyles/Regapps/All]: Enter "R" to purge unused applications. -PURGE removes only one level of reference. Repeat -PURGE until there are no unreferenced named objects. As an alternative, use the following LISP routine: (defun purge-appids ( / name names (vlax-for app (vla-get-registeredapplications (vla-get-activedocument (vlax-get-acad-object (and (setq name (vla-get-name app (not (vl-catch-all-error-p (vl-catch-all-apply 'vla-delete (list (vlax-ename->vla-object (tblobjname "appid" name 8

9 (setq names (cons name names (reverse names Browse to IntelCAD for more information: Drawing Cleanup Using Autodesk MAP RegApps The Drawing Cleanup functionality offers an easy way to improve the accuracy of your maps, correct common map errors (resulting from surveying, digitizing, scanning errors, and so on, and remove unnecessary detail from complex maps. This functionality is essential when you need accurate and complete maps suitable for defining topologies, performing map analyses, or plotting and presentations. With Drawing Cleanup, you can perform the following cleanup actions: delete duplicate objects, erase short objects, break crossing objects, extend undershoots, extend to apparent intersections, snap clustered nodes, dissolve pseudo nodes, erase dangling objects (overshoots, simplify objects, delete zero-length objects, and weed 3D polyline vertices. It's not unusual to cut an enormous file in half by issuing a Cleanup. I use the following options (in order: Zero Length objects Simplify objects Extend undershoots Break crossing objects Erase dangling objects Snap clustered nodes Consult the Help files for more information on using the powerful Cleanup commands. Recovering Damaged Drawings There are several methods for recovering damaged drawing files. It seems everyone has their own tried and true method(s. These are mine: Batch Drawing Converter Can t open the file? Try converting it to an earlier release. I can t express enough the luck I ve had with this. MAP Query Attach the problem drawing to a new drawing using the MAP Workspace. Query it for all of the objects; I ve had better luck with this than the AutoCAD Recover command. 9

10 Partial Open Many times a problem drawing has bad entities on a distinct layer. By opening a drawing one layer at a time and copying and pasting all objects to a single drawing, you may be able to recover most of your work. This could take a while, but when all else fails, it works quite well. Intellicad An old tried-and-true method. Intellicad just does NOT understand AutoCAD objects and will open ALMOST anything without fail. When all else fails, download a trial version. 10