TweetFollow Us on Twitter

December 95 - Graphical Truffles: Making the Most of QuickDraw 3D

Graphical Truffles: Making the Most of QuickDraw 3D

Nick Thompson and Pablo Fernicola

For those of us on Apple's QuickDraw 3D team, the highlight of SIGGRAPH '95 (the annual conference of the ACM's computer graphics interest group) was having the chance to work with developers who were showing QuickDraw 3D products. Considering that we only started working with developers in December 1994, the number of applications already up and running is inspiring. By the time you read this column, 10 or 15 QuickDraw 3D products will be shipping, including modeling and animation software, 3D hardware accelerators, 3D model clip art, and games. More than 50 developers are actively working on products based on QuickDraw 3D, and those will ship in 1996.

If you're not yet a QuickDraw 3D developer and don't want to be left out, take a look at the develop articles "QuickDraw 3D: A New Dimension for Macintosh Graphics" in Issue 22 and "The Basics of QuickDraw 3D Geometries" in Issue 23. This column gives a hodgepodge of additional information.

IMPROVING ACCELERATOR PERFORMANCE

One of the things that has attracted developers to QuickDraw 3D is seamless access to hardware acceleration. In addition to Apple's PCI accelerator card, hardware acceleration cards have been announced by Matrox, Yarc, Radius, and Newer Technology. If you really want your application to fly, you need to make sure that you're using the fastest renderer possible and that if a hardware acceleration card is installed, you're using the card. If you use the QuickDraw 3D API, QuickDraw 3D will take care of this for you, but there's something else you can do that might improve your application's performance.

Certain cards, including Apple's accelerator card, will yield better frame rates in some situations if you use what we call double buffer bypass, an option enabled by a flag. Double buffering causes all objects to be drawn first into a back buffer; this entire buffer is then copied to the front buffer (the window). If the scene you're rendering is simple and thus takes very little time to redraw -- say, less than 1/10 of a second -- enabling double buffer bypass is faster because it avoids having to copy memory from the back buffer to the front buffer. On the other hand, if you use this option with a complex scene, tearing may occur. Therefore, you may want to time a frame (and take into account the complexity of your models) before using double buffer bypass. To time a frame, call the Toolbox routine Microseconds, draw the frame, call Q3Renderer_Sync to make sure the frame has been fully drawn, and then call Microseconds again and subtract the start time from the end time.

If you're using QuickDraw 3D's interactive software renderer, all the code you need to turn on double buffer bypass is shown in Listing 1.

Listing 1. Turning on double buffer bypass

// Create the renderer.
if ((myRenderer = Q3Renderer_NewFromType(kQ3RendererTypeInteractive))
       != nil) {
   if ((myStatus = Q3View_SetRenderer(myView, myRenderer))
          == kQ3Failure) {  // Handle the error.
      ...
   }   // Set bypass.
   Q3InteractiveRenderer_SetDoubleBufferBypass(myRenderer, kQ3True);
}

The interactive renderer can render using software only or using hardware acceleration. The interactive renderer is set by default to look for the best device possible, so if a hardware accelerator is installed, the accelerator will always be used. On occasion, though, you may want to switch from using hardware to using software (for demos or testing, for example). In this case you must explicitly request the software rasterizer, as follows:
Q3InteractiveRenderer_SetPreferences(myRenderer,
   kQAVendor_Apple, kQAEngine_AppleSW);

INTERACTING WITH INPUT DEVICES

QuickDraw 3D provides an input device abstraction layer that allows you to interact with different input devices without having to write special code for each of them. The sample application NewEra demonstrates interaction with tablets and other input devices; this application is available on the CD that comes with the book 3D Graphics Programming With QuickDraw 3D, and a newer version can be found on this issue's CD.

To take advantage of QuickDraw 3D's input device layer, you need to create a tracker object and associate it with a controller object (created by an input device driver), as Listing 2 does. Once you've set up your tracker, you can poll it to get its new position and orientation, as shown in Listing 3. To reflect the change in your scene, you apply the values returned by the tracker to a transform object, affecting either a particular geometry or group (if an object was selected and being manipulated) or the camera, depending on the interaction model for your application.

Listing 2. Creating a tracker object and attaching it to a controller object

theDocument->fPositionSN = 0;
theDocument->fRotationSN = 0;
theDocument->fTracker = Q3Tracker_New(NULL);
myStatus = Q3Controller_Next(NULL, &controllerRef);
while (controllerRef != NULL && myStatus == kQ3Success) {
   Q3Controller_SetTracker(controllerRef, theDocument->fTracker);
   myStatus = Q3Controller_Next(controllerRef, &controllerRef);
}
Listing 3. Updating position and orientation
// We received a null event; grab a new position and orientation
// for the model.
TQ3Boolean      positionChanged;
TQ3Boolean      rotationChanged;

Q3Tracker_GetPosition(doc.fTracker, &doc.fPosition, NULL,
    &positionChanged, &doc.fPositionSN);
Q3Tracker_GetOrientation(doc.fTracker, &doc.fRotation, NULL,
    &rotationChanged, &doc.fRotationSN);
QuickDraw 3D's input device abstraction layer also makes writing input device drivers easier. For example, it took us about three days to write a driver for the Magellan device from Logitech, Inc., a 3D input device with six degrees of freedom. As illustrated in Figure 1, this device enables movement along the x, y, and z axes, as well as rotation about the three axes.

Figure 1. Magellan: a six-degrees-of-freedom input device (courtesy of Logitech)

SETTING THE CORRECT FILE TYPE

When saving QuickDraw 3D metafiles, you should set the file type as '3DMF', regardless of how the contents of the file are formatted (as plain-text or binary, or any combination of the different types of organization, such as database or stream). This will enable the file to be read or opened by other QuickDraw 3D applications. If you'd like your end users to read a file as text, add an Export As Text option to your application and then set the file type to 'TEXT'. This is helpful for debugging (and for sending questions or bugs to Developer Technical Support).

HAVING FUN WITH CUSTOM ATTRIBUTES

By taking advantage of QuickDraw 3D's custom attributes and extensible metafile format, you can have objects that encapsulate specialized data relevant to your application. For instance, to navigate through the World Wide Web in 3D, you can attach Web data (like URLs) to QuickDraw 3D objects as custom attributes. When those objects or scenes are read into one of the many viewers supporting the URL custom attribute, the viewer can communicate through Apple events with applications like Netscape (or your favorite Web browser) to produce 3D navigation. You'll find a sample application that shows how to do this on this issue's CD.

Custom attributes also enable you to associate sound and other data with objects in your 3D scene.

DEBUGGING

There are two really handy techniques that you can use to diagnose problems you may be having with your QuickDraw 3D application. For both of these approaches to debugging your software, you'll want to make sure that you have MacsBug installed on your machine and that you're using the debugging version of the QuickDraw 3D extension supplied with the QuickDraw 3D development software.

The first technique is to install error and warning handlers, described in our article in develop Issue 22. Error and warning handlers are particularly useful for telling you of potential problems with your use of the QuickDraw 3D library. If you don't install error and warning handlers, you won't know if you're doing something that the library identifies as erroneous. Although we stated this in our original article, many developers missed its significance and thus have experienced longer debugging times than necessary and a great deal of frustration.

The second technique is to use a software tool, the 3D debugger, included on this issue's CD. This application enables you to examine the QuickDraw 3D heap and look at the different objects, their attributes, and their reference count. Please note that you're looking under the hood, so you may encounter untyped blocks, and the reference count for objects may reflect references internal to the QuickDraw 3D system.

LOOKING AHEAD

We'll continue to release great new QuickDraw 3D features, so bring your applications along for the ride. By early 1996 we expect to have all major existing 3D applications on the Macintosh using QuickDraw 3D, along with applications that developers port from other platforms. Many 2D applications will be making use of the 3D Viewer as well.

Watch develop for further articles about other aspects of QuickDraw 3D. Meanwhile, you may want to check out the Addison-Wesley book 3D Graphics Programming With QuickDraw 3D (which includes the QuickDraw 3D development software) and see this issue's CD for the development software and the latest versions of the sample code and utility applications. And for the latest news on QuickDraw 3D, see our Web page at http://www.info.apple.com/qd3d.

NICK THOMPSON (eWorld NICKT), transplanted English soccer fan and member of Apple's Developer Technical Support team, thinks that this could be the year for the Arsenal Football Club. With the acquisition of Dutch star Dennis Bergkamp and England striker David Platt, things are looking up at Highbury. By the time you read this, the Premier League standings will tell if this is the dawning of a new era or more of the same "boring, boring, Arsenal," as those charming Spurs fans like to chant.

PABLO FERNICOLA (eWorld EscherDude), of Apple's Interactive Multimedia Group, is much more relaxed since shipping QuickDraw 3D 1.0. He now has time to eat his dad's great barbecue, dally with his lovely wife, and sleep -- although the latter entails the challenge of trying to get his golden retriever, aptly named Mac, to give up some of the space he takes up in the bed. Pablo's latest research project is to find out exactly what the purpose is for those orange balls that one finds on high power transmission lines.

For more information on making your application work with Magellan, contact Stephan Ilberg at Logitech by sending a message to stephan_ilberg@logitech.com.

Thanks to Robert Dierkes and Fábio Pettinati for reviewing this column, and a special thanks to Dan Venolia and David Vasquez for supplying some of the code and applications discussed.

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Splash Cars guide - How to paint the tow...
Splash Cars is an arcade driving game that feels like a hybrid between Dawn of the Plow and Splatoon. In it, you'll need to drive a car around to repaint areas of a town that have lost all of their color. Check out these tips to help you perform... | Read more »
The best video player on mobile
We all know the stock video player on iOS is not particularly convenient, primarily because it asks us to hook a device up to iTunes to sync video in a world that has things like Netflix. [Read more] | Read more »
Four apps to help improve your Super Bow...
Super Bowl Sunday is upon us, and whether you’re a Panthers or a Broncos fan you’re no doubt gearing up for it. [Read more] | Read more »
LooperSonic (Music)
LooperSonic 1.0 Device: iOS Universal Category: Music Price: $4.99, Version: 1.0 (iTunes) Description: LooperSonic is a multi-track audio looper and recorder that will take your loops to the next level. Use it like a loop pedal to... | Read more »
Space Grunts guide - How to survive
Space Grunts is a fast-paced roguelike from popular iOS developer, Orange Pixel. While it taps into many of the typical roguelike sensibilities, you might still find yourself caught out by a few things. We delved further to find you some helpful... | Read more »
Dreii guide - How to play well with othe...
Dreii is a rather stylish and wonderful puzzle game that’s reminiscent of cooperative games like Journey. If that sounds immensely appealing, then you should immediately get cracking and give it a whirl. We can offer you some tips and tricks on... | Read more »
Kill the Plumber World guide - How to ou...
You already know how to hop around like Mario, but do you know how to defeat him? Those are your marching orders in Kill the Plumber, and it's not always as easy as it looks. Here are some tips to get you started. This is not a seasoned platform... | Read more »
Planar Conquest (Games)
Planar Conquest 1.0 Device: iOS Universal Category: Games Price: $12.99, Version: 1.0 (iTunes) Description: IMPORTANT: Planar Conquest is compatible only with iPad 3 & newer devices, iPhone 5 & newer. It’s NOT compatible with... | Read more »
We talk to Cheetah Mobile about its plan...
Piano Tiles 2 is a fast-paced rhythm action high score chaser out now on iOS and Android. You have to tap a series of black tiles that appear on the screen in time to the music, being careful not to accidentally hit anywhere else. Do that and it's... | Read more »
Ultimate Briefcase guide - How to dodge...
Ultimate Briefcase is a simple but tricky game that’s highly dependent on how fast you can react. We can still offer you a few tips and tricks on how to survive though. Guess what? That’s exactly what we’re going to do now. Take it easy [Read more... | Read more »

Price Scanner via MacPrices.net

12-inch 1.2GHz Silver Retina MacBook on sale...
B&H Photo has the 12″ 1.2GHz Silver Retina MacBook on sale for $1399 including free shipping plus NY sales tax only. Their price is $200 off MSRP, and it’s the lowest price for this model from... Read more
iPads on sale at Target: $100 off iPad Air 2,...
Target has WiFi iPad Air 2s and iPad mini 4s on sale for up to $100 off MSRP on their online store for a limited time. Choose free shipping or free local store pickup (if available). Sale prices for... Read more
Target offers Apple Watch for $100 off MSRP
Target has Apple Watches on sale for $100 for a limited time. Choose free shipping or free local store pickup (if available). Sale prices for online orders only, in-store prices may vary: - Apple... Read more
Apple refurbished 2014 13-inch Retina MacBook...
Apple has Certified Refurbished 2014 13″ Retina MacBook Pros available for up to $400 off original MSRP, starting at $979. An Apple one-year warranty is included with each model, and shipping is free... Read more
Macs available for up to $300 off MSRP, $20 o...
Purchase a new Mac or iPad using Apple’s Education Store and take up to $300 off MSRP. All teachers, students, and staff of any educational institution qualify for the discount. Shipping is free, and... Read more
Watch Super Bowl 50 Live On Your iPad For Fre...
Watch Super Bowl 50 LIVE on the CBS Sports app for iPad and Apple TV. Get the app and then tune in Sunday, February 7, 2016 at 6:30 PM ET to catch every moment of the big game. The CBS Sports app is... Read more
Two-thirds Of All Smart Watches Shipped In 20...
Apple dominated the smart watch market in 2015, accounting for over 12 million units and two-thirds of all shipments according to Canalys market research analysts’ estimates. Samsung returned to... Read more
12-inch 1.2GHz Retina MacBooks on sale for up...
B&H Photo has 12″ 1.2GHz Retina MacBooks on sale for $180 off MSRP. Shipping is free, and B&H charges NY tax only: - 12″ 1.2GHz Gray Retina MacBook: $1499 $100 off MSRP - 12″ 1.2GHz Silver... Read more
12-inch 1.1GHz Gray Retina MacBook on sale fo...
B&H Photo has the 12″ 1.1GHz Gray Retina MacBook on sale for $1199 including free shipping plus NY sales tax only. Their price is $100 off MSRP, and it’s the lowest price available for this model... Read more
Apple now offering full line of Certified Ref...
Apple now has a full line of Certified Refurbished 2015 21″ & 27″ iMacs available for up to $350 off MSRP. Apple’s one-year warranty is standard, and shipping is free. The following models are... Read more

Jobs Board

*Apple* Retail - Multiple Positions (US) - A...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
*Apple* Subject Matter Expert - Experis (Uni...
This position is for an Apple Subject Matter Expert to assist in developing the architecture, support and services for integration of Apple devices into the domain. Read more
*Apple* Macintosh OSX - Net2Source Inc. (Uni...
…: * Work Authorization : * Contact Number(Best time to reach you) : Skills : Apple Macintosh OSX Location : New York, New York. Duartion : 6+ Months The associate would Read more
Computer Operations Technician ll - *Apple*...
# Web Announcement** Apple Technical Liaison**The George Mason University, Information Technology Services (ITS), Technology Support Services, Desktop Support Read more
Restaurant Manager - Apple Gilroy Inc./Apple...
…in every aspect of daily operation. WHY YOU'LL LIKE IT: You'll be the Big Apple . You'll solve problems. You'll get to show your ability to handle the stress and Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.