Publishers of technology books, eBooks, and videos for creative people

Home > Articles > Web Design & Development > PHP/MySQL/Scripting

3D Modeling Basics

This chapter is from the book


In general, transforms are operations that alter the position, size, or orientation of an object. Such basic transforms as Move, Scale, and Rotate are essential to any modeling task, because you have to be able to adjust the position and orientation of the separate objects to make a scene.

Every program uses a different interface for controlling transforms, but many of them involve having some sort of gizmo appear inside or around a 3D object when it is selected. The gizmo usually includes a visual axis indicator representing the local axes of the object and its pivot point, and has some sort of handles you drag with the mouse to perform the selected transform.

Transforms may be affected by axis locks or axis constraints, which are controls in the software that enable you to turn off movement along the X, Y or Z-axis, or any combination of them. Axis constraints enable you to transform objects along the desired axis only, which prevents accidental movement in unwanted directions.


Because so many things affect axis orientation, what is the correct axis one minute might be wrong the next. So, if your object stubbornly refuses to move, rotate, or do any other transform in the desired direction, check to see whether axis constraints or some other types of locks are active.

The current coordinate system (view, world, local) in use can have a big impact on transforms. Transforms may also be affected by the pivot point location, because they use it as the center of the transform operation. The pivot point may be centered in the object or offset into the boonies somewhere. Usually an indicator of some kind shows you whether the program is set to use the object's pivot point or whether it is using one that the software sets in the center of the object.


It comes as no surprise that Move relocates objects, allowing you to place shapes and objects anywhere in the 3D universe. In most cases, this is done with the mouse, but many programs also provide a way to enter this data numerically for precise adjustments.

Move may be affected by the current coordinate system and axis constraints only, unless inverse kinematics (see Chapter 9, "Animation") are in effect. The pivot point setting has no effect on Move.


Rotate makes an object revolve around the selected axis. The tricky part about Rotate is making sure everything is set up so that the object revolves in the way you want. For example, do you want to rotate using the Screen, World, or Local axes? Which pivot point are you using, and is it centered in the object, or offset somewhere? The pivot point of an object is located at the junction of its local axes, similar to the way the origin point resides at the center of the three world axes. When you rotate the object, it revolves around this pivot point. Your 3D software will probably have some sort of controls for defining multiple pivot points and selecting which pivot point you want to use for a given Rotate operation.

Imagine you were making a simple model of the solar system. For the sphere representing Earth, you would want to set the pivot point at its center and rotate it around the Y (up/down) axis, so it spins around more or less like it should. (Ignore the fact that the Earth is tilted slightly off-axis for the moment.) In addition to spinning around like a top, the Earth also has to orbit around the Sun, which means you also need to have another pivot point in the center of the sphere representing old Sol. When you rotate around that center point, the Earth sphere will move in a broad circle around the Sun sphere.

When doing rotation or other transforms, make sure your software's visual axis indicator is turned on, if it has one. This will tell you where and which way the axes are located before you do the rotation. As you would expect, the axis you choose to rotate the object around has a dramatic effect on the results (see Figure 3.26).

Figure 3.26FIGURE 3.26 Rotate revolves objects around the desired axis. (a) The base object. (b) Rotation around the X-axis. (c) Rotation around the Y-axis. (d) Rotation around the Z-axis.


Use Scale to adjust the overall size of an object. Like other transforms, the results of a scale operation may vary according to the coordinate system, axis constraint settings, and pivot point. For example, if the X-axis is the only one active, a scale stretches the object horizontally only. If all three axes are active, scale re-sizes the object in all directions (see Figure 3.27).

Figure 3.27FIGURE 3.27 The Scale command re-sizes objects along the desired axes. (a) The base object. (b) Scaling the X-axis. (c) Scaling the Y-axis. (d) Scaling the Z-axis. (e) Scaling all axes simultaneously.

If the scale operation is set to use the object's non-centered pivot point, the scale will transform the object toward or away from that point. For example, if the pivot point is located on the left face of a cube, a scale operation will leave the left face in the same position while scaling all of the other faces away from it.


The transform command Mirror either reverses an object or copies a reversed version of it along the selected axis (see Figure 3.28). Some programs enable you to select multiple axes to mirror around as well. Mirror may be affected by the coordinate system and axis constraints.

Figure 3.28FIGURE 3.28 Effects of mirror: (a) The object is selected, and a mirror axis defined. (b) If the user elects to Mirror-copy the object, a second reversed version is created.

In addition to making reversed copies of entire objects, Mirror can be a great help when dealing with complex symmetrical objects, like human faces. If you work with only the right or left half of the face when editing, you reduce the clutter of having all those extra vertices. When you want to check your work, Mirror-copy the face to create the missing side.


Align enables you to bring object surfaces flush with each other or center multiple objects along one or more axes. Align is great for getting objects lined up the way you want them without tedious zooming and repositioning. Align is also useful for quickly bringing an object into the appropriate area of a scene if it has been accidentally created or imported into some obscure corner of 3D space. Align may be affected by the axis constraints.

There are quite a few different Align settings, depending on your software. The basic ones are Align Center, Align Left, and Align Right, which do exactly what they say (see Figure 3.29). The alignment can take place on one or more axes, and some products enable you to align to any object, face, edge, or vertex to another.

Figure 3.29FIGURE 3.29 Typical Align types: (a) The base objects are currently centered on the Z-axis, and the bottoms are aligned with each other. In the following examples, the small cube will be aligned to the larger one. (b) Align Center, on both the X- and Y-axis. (c) Align Left on the X-axis. (d) Align Left on the X-axis, plus Align Center on the Y-axis.

Peachpit Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from Peachpit and its family of brands. I can unsubscribe at any time.


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about Peachpit products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information

To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.


Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites; develop new products and services; conduct educational research; and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.


If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information

Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.


This site is not directed to children under the age of 13.


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information

If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at and we will process the deletion of a user's account.


Users can always make an informed choice as to whether they should proceed with certain services offered by Adobe Press. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive:

Sale of Personal Information

Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to

Supplemental Privacy Statement for California Residents

California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure

Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact

Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice

We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020