TweetFollow Us on Twitter

Oct 97 - Macintosh Q and A

Volume Number: 13 (1997)
Issue Number: 10
Column Tag: develop

Macintosh Q & A

by Apple Developer Support Center

All Geometry Vertices Need UV Parameterization

Q. Is it possible to apply UV parameterization to some, but not all of a geometry's vertices?

A. No, you must apply UV parameterization to all of the vertices in a given geometry.


Default Number Of Surface Planes

Q. When rendering a QuickDraw 3D 1.5 file containing objects such as cylinders and ellipsoids, the default number of surface planes is much higher than in QD3D version 1.0.6. While this looks nice, it requires more memory. Is there a way in my application to limit the 'resolution' (i.e. the number of surface planes) used by QD3D 1.5?

A. You can use a subdivision style to get control over the number of faces generated. For example, you can create a subdivision style object as follows:

theSubdivisionStyleData.method = 
    kQ3SubdivisionMethodScreenSpace;
theSubdivisionStyleData.c1 = (float)20;
theSubdivisionStyleData.c2 = (float)20;
mSubdivisionStyle =
    Q3SubdivisionStyle_New(&theSubdivisionStyleData);

You can then submit the subdivision style in your rendering loop before you submit your geometry.


EllipsoidData Caps Field Explanation

Q. I am perplexed as to what the caps field in the TQ3EllipsoidData structure is used for. Can you explain?

A. Here's an explanation. If you cut a pool ball in half, you get a solid hemisphere. If you cut a basketball in half, you get a hollow hemisphere. The intention of the caps is to specify which sort of a ball you'd like to pretend you're rendering. You will IN THE FUTURE (NOT for 1.5.1) be able to specify min and max parameter values, making partial ellipsoids (cones, etc.). When this feature is released, you can either leave the caps field value as none (kQ3EndCapNone), in which case you'll get a hollow-looking partial sphere, or interior (kQ3EndCapMaskInterior), in which case you'll get a solid-looking partial sphere.


Using Hardware Acceleration

Q. How do I set up QuickDraw 3D hardware acceleration? Is there any specific API calls I have to make? Or does hardware acceleration just work automatically if you have a hardware accelerator board installed?

A. The QD3D interactive renderer automatically uses hardware acceleration if a card is present (and selects the best hardware if there are multiple cards). The wireframe renderer does not.

You can tell a renderer to use hardware acceleration with the Q3InteractiveRenderer_SetPreferences() and Q3View_SetRenderer functions.

Check out the BoxPaint sample code from the QD3D SDK which uses the above functions to set the renderer.


Default Surface/Shader UV Params For Caps of Cones & Cylinders

Q. Does anyone know what the default surface/shader UV parameterizations are for the caps of cones and cylinders in QuickDraw 3D version 1.5?

A. Check out the article titled, "New QuickDraw 3D Geometries", by Philip J. Schneider in develop journal issue 28. Look for the section "Ellipsoids, Cones, Cylinders, and Tori", where you'll find a discussion about the default UV parameterization of these primitives. Here's a relevant excerpt from the article: "For the cone and cylinder, the parametric origin is on the bottom edge, at the point where the majorRadius vector ends. V goes up while U goes around in the direction shown by the arrows. The bottom of the cone, and the top and bottom of the cylinder, are parameterized exactly like the disk."

The discussion about the disk primitive is in the article as well.

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Unite 3 3.1 - Turn websites into full-fe...
Unite 3 lets you turn websites into apps on your Mac and change the way you use your computer forever Creating your app It all starts with the new Unite creation tool. Simply enter a name for your... Read more
App Tamer 2.5.2 - Efficiently manage you...
App Tamer tames your processor-monopolizing apps and keeps them from chewing up excessive CPU time and battery life. Powered by a unique AutoStop feature, App Tamer stops each application when you... Read more
Sid Meier's Civilization IV 1.74 -...
Note: Sid Meier's Civilization IV is no longer under development and the developer provides no support for it. With Civilization IV, history as you know it, is history. Rule throughout time and... Read more
Day One 4.15.3 - Maintain a daily journa...
Day One is an easy, great-looking way to use a journal / diary / text-logging application. Day One is well designed and extremely focused to encourage you to write more through quick Menu Bar entry,... Read more
Backblaze 7.0.1.450 - Online backup serv...
Backblaze is an online backup service designed from the ground-up for the Mac. With unlimited storage available for $6 per month, as well as a free 15-day trial, peace of mind is within reach with... Read more
Visual Studio Code 1.47.0 - Cross-platfo...
Visual Studio Code provides developers with a new choice of developer tool that combines the simplicity and streamlined experience of a code editor with the best of what developers need for their... Read more
Apple Pages 10.1 - Apple's word pro...
Apple Pages is a powerful word processor that gives you everything you need to create documents that look beautiful. And read beautifully. It lets you work seamlessly between Mac and iOS devices, and... Read more
Shimo 5.0.2 - VPN client for everyone.
Shimo is the most versatile VPN client for OS X and it enables really everybody to master secure network. It supports more protocols than any other VPN application out there! CiscoVPN, AnyConnect,... Read more
Yasu 6.0.1 - System maintenance app.
Note: Yasu is not being sold anymore and is listed only for people who had purchased it in the past. Yasu was created with system administrators who service large groups of workstations in mind, Yasu... Read more
Keynote 10.1 - Apple's presentation...
Easily create gorgeous presentations with the all-new Keynote, featuring powerful yet easy-to-use tools and dazzling effects that will make you a very hard act to follow. The Theme Chooser lets you... Read more

Latest Forum Discussions

See All

Puzzle & Dragons welcomes the cast o...
Puzzle & Dragons has a history of wild crossovers, and its latest is no exception. The gates of hell are now open, and the cast of Devil May Cry have made their grand entrance into the world Puzzle & Dragons. The collaboration is set to... | Read more »
Meteorfall: Krumit's Tale is launch...
Meteorfall: Krumit's Tale is getting an iOS & Android beta test this Thursday, and you can sign up now to get involved. [Read more] | Read more »
Marvel Duel, NetEase's promising ca...
Marvel Duel, NetEase's collectable card battler, has now opened for pre-registration in Thailand, Indonesia, Malaysia, and the Philippines. [Read more] | Read more »
PUBG Mobile teams up with Yamaha for a l...
PUBG Mobile has had various collaborations with various companies since it first burst onto the scene. The latest sees the popular battle royale title teaming up with vehicle and marine products company Yamaha, meaning players can take one of... | Read more »
Marvel Super War launches its third seas...
Marvel Super War, NetEase's popular MOBA, has kicked off its third season today, introducing its Zone Invasion beta and an all-new playable superhero. [Read more] | Read more »
Brave Dungeon, Unlock Games' idle-R...
Brave Dungeon, Unlock Games' idle-RPG and auto chess title, has been downloaded over 1 million times since it launched last week. To commemorate reaching this milestone the developers have decided to host a series of in-game events. [Read more] | Read more »
Clash Royale: The Road to Legendary Aren...
Supercell recently celebrated its 10th anniversary and their best title, Clash Royale, is as good as it's ever been. Even for lapsed players, returning to the game is as easy as can be. If you want to join us in picking the game back up, we've put... | Read more »
Steam Link Spotlight - Disco Elysium
Steam Link Spotlight is a feature where we look at PC games that play exceptionally well using the Steam Link app. Our last entry was Signs of the Sojourner Read about how it plays using Steam Link over here. | Read more »
Distract Yourself With These Great Mobil...
There’s a lot going on right now, and I don’t really feel like trying to write some kind of pithy intro for it. All I’ll say is lots of people have been coming together and helping each other in small ways, and I’m choosing to focus on that as I... | Read more »
Pokemon Go's July Community Day wil...
Pokemon Go developers have announced the details concerning the upcoming Gastly Community Day. This particular event was selected by the players of the game after the Gas Pokemon came in second place after a poll that decided which Pokemon would... | Read more »

Price Scanner via MacPrices.net

New Verizon offer: $150 off on Apple Watch 5...
Verizon is offering a $150 discount on Apple Watch Series 5 models for a limited time. Use code SMARTWATCH150 at checkout to take advantage of this offer. The fine print: “New line of service and... Read more
Xfinity Mobile offers $200 off any new Apple...
New and existing customers can take $200 off the purchase of any new Apple iPhone model at Xfinity Mobile through 8/17/20. Service plan required: The fine print: “New customers and new line... Read more
Clearance 2019 13″ 1.4GHz/256GB MacBook Pro a...
Other World Computing has clearance, refurbished, 2019 13″ 1.4GHz/256GB MacBook Pros available for $1099 in both Space Gray and Silver colors. Their price is $400 off Apple’s original MSRP for these... Read more
Apple has 2020 13″ 4-Core MacBook Airs availa...
Apple has a full line of Certified Refurbished 2020 13″ 4-Core MacBook Airs available for $200 off the cost of new models. Each MacBook features a new outer case, comes with a standard Apple one-year... Read more
Apple restocks clearance 2019 13″ MacBook Pro...
Apple has restocked Certified Refurbished 2019 13″ 1.4GHz 4-Core Touch Bar MacBook Pros starting at $979 and up to $440 off original MSRP. Apple’s one-year warranty is included, shipping is free, and... Read more
US Cellular offers $300 off any new Cellular...
US Cellular is offering a $300 discount on any new Cellular Apple iPad, iPad Air, iPad Pro, or iPad mini with a new line of service. According to US Cellular, “Promotional pricing requires purchase... Read more
Sale! 16″ MacBook Pros for $400 off Apple’s M...
Amazon has 16″ MacBook Pros on sale for $400 off Apple’s MSRP today with prices starting at $1999. Shipping is free: – 2019 16″ 2.6GHz 6-Core MacBook Pro Space Gray: $1999.99 $400 off MSRP – 2019 16... Read more
Lowest price ever: Apple AirPods Pro for $214...
Amazon-owned Woot has new Apple AirPods Pro on sale for today only (Monday, July 13th) for $214.99 including free shipping for Prime members. Their price is $35 off Apple’s MSRP, and it’s the lowest... Read more
Woot is selling refurbished Apple iPhones tod...
Amazon-owned Woot is selling refurbished unlocked Apple iPhones today for as low as $99. Shipping is free for prime members. The following models are available, and note that many will sell out... Read more
Take $50 off the 64GB Apple iPhone SE at Simp...
Use coupon code SUMMER2020 at Simple Mobile through July 31, 2020, and take 20% off the 64GB Apple iPhone SE + service plan. This is in addition to their standard $50 discount on the iPhone SE.... Read more

Jobs Board

Perioperative RN - ( *Apple* Hill Surgical C...
Perioperative RN - ( Apple Hill Surgical Center) Tracking Code 62018 Job Description Monday - Friday - Full Time Days Possible Saturdays General Summary: Under the Read more
Surgical Coord/Scheduler-MG - *Apple* Hill...
Surgical Coord/Scheduler-MG - Apple Hill Medical Center - (full-time) - Days Tracking Code 62537 Job Description General Summary: Under general supervision, provides Read more
Office Assistant - *Apple* Hill Medical Cent...
Office Assistant - Apple Hill Medical Center- (part-time) - Days Tracking Code 62649 Job Description General Summary: Under general supervision, performs diversified Read more
Blue *Apple* Cafe Student Worker - Fall - P...
…to enhance your work experience. Student positions are available at the Blue Apple Cafe. Employee meal discount during working hours is provided. Duties include food Read more
Geek Squad Advanced Repair *Apple* Professi...
**769390BR** **Job Title:** Geek Squad Advanced Repair Apple Professional **Job Category:** Store Associates **Store Number or Department:** 000580-Reading-Store Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.