Design Integration Laboratory

Modeling Notes

Tips for Using DesignWorkshop with Bigger Models

a.k.a. -- DesignWorkshop Survival Skills

Allocate Enough Memory | Save System Memory | Avoid Risk Factors | Avoid Known Bugs

Most Common Source of Problems -- Not Enough Memory for the Model .

A very rough formula would be 6000K RAM base for DesignWorkshop (DW) itself, plus 1500K more RAM for each 100K of file, to ensure full reliability for cutting and pasting, shadow-casting, printing, etc. This formula produces the following table of suggested memory allocations for DesignWorkshop:

Model
File  Suggested
Size  DW RAM 

100K  7500K

200K  9000K

300K  10200K . <-- easy on a 16MB-RAM PCI Mac

400K  12000K . <-- reasonable max on a 16MB PCI Mac without virtual memory

500K  13500K . <-- okay on a 16MB PCI Mac with minimum virtual memory (17MB)

600K  15000K . <-- reasonable on a 16MB PCI Mac with 20-24MB virtual memory

700K  16500K

800K  18000K . <-- really slow on a 16MB PCI Mac with 24+MB virtual memory

900K  19500K . <-- okay on a 24MB Power Mac with minimum virtual memory (25MB)

1000K  21000K

1200K  24000K . <-- easy on a 32MB PCI Mac

1400K  27000K . <-- reasonable max on a 32MB PCI Mac without virtual memory

1600K  30000K . <-- reasonable on a 16MB PCI Mac with 36+MB virtual memory

2000K  36000K

4000K  66000K . <-- largest known models made with DW PPC 1.2.2

Special conditions may call for even more RAM, such as printing at very large sizes, or working with a monitor setting of millions of colors (instead of thousands). Working in wireframe, cutting and pasting only part of a model at once, and exporting PICTs instead of printing directly from DW will help make the most of your available memory if you're in a pinch. If you have the RAM, use it -- there's no penalty for allocating too much! However, if you have to use VM, then there is a performance penalty for using more, so you'll want to work the boundary.

See also -- Building Model Quality Tips, especially regarding both conservation of objects and conservation of faces.

Allocate Enough Memory | Save System Memory | Avoid Risk Factors | Avoid Known Bugs

System Adjustments to Maximize Free Memory :

There are some things which can be removed from the system of your Macintosh which will free up memory for model building. THIS MUST BE DONE CAREFULLY, otherwise, you could render your computer inoperative, and waste a lot of time getting it fixed up.

Note: After making these changes, you will have to restart your Mac for them to take effect. Before restarting, in the Finder use the Apple menu About This Macintosh... command to check the memory your system is using. Write down two numbers, the Largest Unused Block, and the System Software memory size. After you restart, check these numbers again to see how much working memory you've gained.

Note: These notes are based on Macintosh System 7.5.x, and should be used with caution.

In the "Memory" Control Panel
The Disk Cache Size should be set near or at the minimum of 32K before resorting to the use of Virtual Memory, and also while using virtual memory. The Modern Memory Manager should be On, if that is an option.
It can be very useful to turn on the very minimum amount of virtual memory, since this gives the Macintosh internal memory manager some more sophisticated options, which allow the main memory to be used more efficiently without a big performance impact.
Control Panels

In your System Folder, make a new folder called Control Panels-Disabled. This is an important step to keep the parts of your operating system organized. Then open your Control Panels folder, set its Finder window to view by Name, and move some or all of the following items from the Control Panels folder into the Control Panels-Disabled folder, to take them out of use (if you don't have some of these items, don't worry - just skip them):
Auto Power On/Off, AutoRemounter, CloseView, Cache Switch, Control Strip, Desktop Patterns, Easy Access, Extensions Manager, Launcher, Macintosh Easy Open, PC Exchange, Power Macintosh Card (unless you are using one), anything beginning with PowerBook (unless you are using one), Serial Switch, Token Ring, WindowShade. Also, if you can live without file sharing to your Mac, you should also move over File Sharing Monitor, Sharing Setup, and Users & Groups.
Extensions

In your System Folder, make a new folder called Extensions-Disabled. This is an important step to keep the parts of your operating system organized. Then open your Extensions folder, set its Finder window to view by Name, and move some or all of the following items from the Extensions folder into the Extensions-Disabled folder, to take them out of use (if you don't have some of these items, don't worry - just skip them):
A/Rose, Apple Guide, AppleScript, Color Picker, EM Extension, Finder Scripting Extension, MacTCP Token Ring Extension, anything beginning with Microsoft (unless you need to use a Microsoft application), anything beginning with PowerBook (unless you are using one), extensions for printers you will never use, anything beginning with Quadra (unless you are using one). Also, if you can live without file sharing to your Mac, you should also move over the File Sharing Extension.

Allocate Enough Memory | Save System Memory | Avoid Risk Factors | Avoid Known Bugs

Other Sources of Problems, and Ways to Avoid Them:

Unextruded polylines, or zero-thickness extrusions, may cause problems when shading.

Workaround:. Delete these objects if they're not needed anymore, or if they are still useful, move them to a separate phase which you can keep turned off when shading.

Identical, Duplicate Objects occupying the same space.

Workaround:. Redundant objects occur only by a form of user error, usually from copying and pasting within a model, and then not doing anything with the pasted objects. They can make a model very confusing to work on, waste large amounts of memory, and sometimes can cause rendering problems. Avoid them by making sure you use all the new objects after you have pasted.

If your model already has many redundant objects,. you can sift them out by carefully going through the following process on a copy of your model file. Click to carefully select one object, then hit the Delete key. If the exact object disappears when you delete, immediately Undo to bring it back, and then immediately Hide that object so you know it has already been checked, and click on the next object. If the exact object still appears to be there after deleting, what you are seeing is a duplicate object, so leave the previous copy deleted, and click again on the remaining object to repreat the process on it.
If there's only one set of redundant objects (two of each object total), the object will properly disappear the second time, so Undo, Hide, and go to the next object. But if you pasted several times, there could be several sets of redundant objects, and you'll have to select and delete repeatedly to get down to the last object, which disappears when deleted, so you should Undo, Hide, and so on.

Too many openings in one piece of wall.

Workaround:. Make the wall out of a few pieces with several openings each, rather than one large piece with many openings. You may be able to just trim an existing wall into more modest sections.

Large horizontal openings, especially large horizontal poly-openings.

Workaround:. Large horizontal openings should be constructed by building the solid shapes around the opening, using blocks or extrusions,

Objects oversized compared to the rest of the model, such as very long walls, or large, complex expanses of floor or roof made in one piece.

Workaround:. Use the Trim tool to slice these oversize objects into a few smaller pieces, but don't overdo it. Objects which are shorter than half the diagonal length of the overall model should be fine.

Self-intersecting or non-planar objects.

Workaround:. The most common source of self-intersecting problems is messy corners on extrusions, sometimes almost microscopically, so you have to zoom way in to see the source of the trouble. These objects should be carefully reshaped to clean up their geometry. If there are several edges all bunched together in the corner of an extrusion, it may be best to trim off the mess (with a small cut across the extrusion end-cap) and then reshape the simpler resulting piece.

Very large or very fine background grids.

Workaround:. Make the background grid smaller or coarser, or remember to turn it off when shading.

Risky disk operations.

Avoid risky disk operations by only working on a local hard disk, period.

Never work directly off a floppy disk, or save directly to a floppy disk, or work directly off a network disk, or save to directly to a network disk, or work on a DesignWorkshop file sitting on the Desktop, or on a file in a folder which is out on the Desktop.
Back your work up to floppy disks by first quitting DesignWorkshop, and then dragging the model file over to the floppy disk in the Finder.

The only partial, careful exception to this is necessary on the five Power Mac 7500's in the UO Architecture DCL. Due to a bug in the security software, these Macs require you to save through an application to back your work up to a floppy disk. For safe operation on these machines, you should ALWAYS save first to the hard disk, then Save As to the floppy disk, then promptly quit, and check the file size of the corresponding model file on both the hard disk and the floppy disk, using the Finder Get Info command. Compare the numbers in parentheses for (X bytes used). If these are not the same, open the model file from the hard disk, and Save As onto a different floppy disk, then check the file sizes again.

Allocate Enough Memory | Save System Memory | Avoid Risk Factors | Avoid Known Bugs

Known Bugs to Avoid

Undoing the creation of a poly-opening.

Workaround:. Select and delete the poly-opening, instead of undoing the creation.

Resizing the length or width of a rectangle using the Object Info box, before extruding the rectangle.

Workaround:. Give the rectangle some thickness, either by dragging of using the object info box, then change its length and/or width.

Closing a library document with objects still selected, after copying objects, may cause the application to crash.

Workaround:. When using library files, be sure to deselect all objects before closing the library model. A quick, easy, reliable way to deselect all objects in a model is to double-click on the Arrow tool.

Deleteing Phases may occasionally cause subtle file problems.

Workaround:. To avoid the possibility of these problems, rename phases, but don't delete them.

Workaround:. If you feel you need to delete phases, only do it on a copy of your model, never on an only original. Then delete phases as you wish, and immediately save, quit, and reopen the file to carefully check that it is intact, and all the objects still show in the normal wireframe view. If the file reopens properly, you can go ahead and use it. Otherwise, go back to the original version.

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http://www.dil.uoregon.edu/computing/tools/modeling/big_model_tips.html
Posted 95.11.27 KMM, rev. 96.03.19