• Products
  • Solutions
  • Made with Unity
  • Learning
  • Support & Services
  • Community
  • Asset Store
  • Get Unity

UNITY ACCOUNT

You need a Unity Account to shop in the Online and Asset Stores, participate in the Unity Community and manage your license portfolio. Login Create account
  • Blog
  • Forums
  • Answers
  • Evangelists
  • User Groups
  • Beta Program
  • Advisory Panel

Navigation

  • Home
  • Products
  • Solutions
  • Made with Unity
  • Learning
  • Support & Services
  • Community
    • Blog
    • Forums
    • Answers
    • Evangelists
    • User Groups
    • Beta Program
    • Advisory Panel

Unity account

You need a Unity Account to shop in the Online and Asset Stores, participate in the Unity Community and manage your license portfolio. Login Create account

Language

  • Chinese
  • Spanish
  • Japanese
  • Korean
  • Portuguese
  • Ask a question
  • Spaces
    • Default
    • Help Room
    • META
    • Moderators
    • Topics
    • Questions
    • Users
    • Badges
  • Home /
  • Help Room /
avatar image
0
Question by Matthewek · Jan 31, 2017 at 02:34 PM · rotationtransformquaternioneulerlinecast

Rotating Vector3, linecast

Hello, I am am creating a Physics2d.LineCast that starts in middle of the objects, and ends in same vector with x bigger by 1 unit. It looks like that:

alt text

I am trying to make this linecast follow transforms rotation, so for example, if I would rotate my transform by 90 degrees on Z axis, that would be my expectation (left) but instead I get linecast with weird rotation plus linecast is much longer (depends on transforms rotation)

alt text

I am drawing linecast and rotating it this way:

 void FixedUpdate ()
 {
         Vector3 myVector = transform.position + new Vector3(1, 0, 0);
         Vector3 rotatedVector = transform.rotation * myVector;
         Debug.DrawLine(transform.position, rotatedVector);
 }

But as you can see it does not work as intended, I would appreciate help how to rotate Vector3 properly, so it follows transforms rotation. Thank you.

2.jpg (36.0 kB)
1.jpg (9.2 kB)
Comment
Add comment
10 |3000 characters needed characters left characters exceeded
▼
  • Viewable by all users
  • Viewable by moderators
  • Viewable by moderators and the original poster
  • Advanced visibility
Viewable by all users

1 Reply

· Add your reply
  • Sort: 
avatar image
1
Best Answer

Answer by Hellium · Jan 31, 2017 at 02:35 PM

In Vector Arithmetic, a sum of two vectors results in a point, not a vector while the difference between two points results in a vector. Here, you need to rotate a directional vector, thus, simply do the following :

     void FixedUpdate()
     {
         Vector3 rotatedVector = transform.rotation * new Vector3(1, 0, 0);
         Debug.DrawLine( transform.position, transform.position + rotatedVector );
     }
Comment
Add comment · Show 1 · Share
10 |3000 characters needed characters left characters exceeded
▼
  • Viewable by all users
  • Viewable by moderators
  • Viewable by moderators and the original poster
  • Advanced visibility
Viewable by all users
avatar image Matthewek · Jan 31, 2017 at 02:38 PM 0
Share

Thank you very much, indeed I did not think about it this way, once again thanks.

Your answer

Hint: You can notify a user about this post by typing @username

Up to 2 attachments (including images) can be used with a maximum of 524.3 kB each and 1.0 MB total.

Welcome to Unity Answers

The best place to ask and answer questions about development with Unity.

To help users navigate the site we have posted a site navigation guide.

If you are a new user to Unity Answers, check out our FAQ for more information.

Make sure to check out our Knowledge Base for commonly asked Unity questions.

If you are a moderator, see our Moderator Guidelines page.

We are making improvements to UA, see the list of changes.



Follow this Question

Answers Answers and Comments

5 People are following this question.

avatar image avatar image avatar image avatar image avatar image

Related Questions

unwanted rotation in y axis 0 Answers

limit Quaternion.Euler rotation 2 Answers

How can I set rotation properly? 0 Answers

How to make a 2D sprite rotate towards a specific point while facing perpendicular to the camera ? 1 Answer

Quaternion Rotation - AngleAxis/EulerAngle 2 Answers


Enterprise
Social Q&A

Social
Subscribe on YouTube social-youtube Follow on LinkedIn social-linkedin Follow on Twitter social-twitter Follow on Facebook social-facebook Follow on Instagram social-instagram

Footer

  • Purchase
    • Products
    • Subscription
    • Asset Store
    • Unity Gear
    • Resellers
  • Education
    • Students
    • Educators
    • Certification
    • Learn
    • Center of Excellence
  • Download
    • Unity
    • Beta Program
  • Unity Labs
    • Labs
    • Publications
  • Resources
    • Learn platform
    • Community
    • Documentation
    • Unity QA
    • FAQ
    • Services Status
    • Connect
  • About Unity
    • About Us
    • Blog
    • Events
    • Careers
    • Contact
    • Press
    • Partners
    • Affiliates
    • Security
Copyright © 2020 Unity Technologies
  • Legal
  • Privacy Policy
  • Cookies
  • Do Not Sell My Personal Information
  • Cookies Settings
"Unity", Unity logos, and other Unity trademarks are trademarks or registered trademarks of Unity Technologies or its affiliates in the U.S. and elsewhere (more info here). Other names or brands are trademarks of their respective owners.
  • Anonymous
  • Sign in
  • Create
  • Ask a question
  • Spaces
  • Default
  • Help Room
  • META
  • Moderators
  • Explore
  • Topics
  • Questions
  • Users
  • Badges