• 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 /
avatar image
2
Question by Noam · Apr 03, 2011 at 11:24 AM · physicsraycast

Raycasting to the bottom side of a plane?

Hi,

I have a short question. Currently, If I use Physics.Raycast and cast a ray from below a plane, it won't hit it. If I cast a ray from above, it will.

Is there a way to have the raycast hit in both ways, without creating a manual dual-sided plane object?

Thanks!

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

2 Replies

· Add your reply
  • Sort: 
avatar image
3
Best Answer

Answer by Bunny83 · Apr 03, 2011 at 12:03 PM

Since the default plane in Unity have just a Mesh collider, you can replace it with a BoxCollider and make it very thin. I guess a BoxCollider performs better than two Meshcollider with a 200 tris mesh ;) (the plane have 10*10*2 tris).

The opposite Raycast was also my first thought, but I guess you will detect a lot of other colliders than the one you'd expected. I think I would use a BoxColider, but it depends on your needs.

Comment
Add comment · Show 4 · 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 Statement · Apr 03, 2011 at 01:26 PM 0
Share

Bunny: You'd do a RaycastAll and get the last hit on the reverse operation.

avatar image Statement · Apr 03, 2011 at 01:27 PM 0
Share

I'd pick a BoxCollider any day I could make the swap. However, if you're dealing with custom meshes then you obviously can't do this since you'd expect some other shape.

avatar image Bunny83 · Apr 03, 2011 at 08:49 PM 0
Share

That's true, but it's not very effective to use RaycastAll. Also it depends on what information you need from the raycast. RaycastAll juat gives you a list of all colliders and no hitpoint(s). For custom meshes you need to use a mesh collider and then you have no way around that. If you want to check for one specific Collider only you can use Collider.Raycast ins$$anonymous$$d of Physics.Raycast. Collider.Raycast can only hit this collider.

avatar image Bunny83 · Apr 03, 2011 at 08:52 PM 0
Share

BTW: Do you know if you can rely on the order of the returned collider array of RaycastAll? Never tried that.

avatar image
1

Answer by Statement · Apr 03, 2011 at 11:33 AM

No. You'll have to do two opposite Raycasts, or two opposite planes. I'd suggest the latter.

Comment
Add comment · 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

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

If you’re new to Unity Answers, please check our User Guide to help you navigate through our website and refer to our FAQ for more information.

Before posting, make sure to check out our Knowledge Base for commonly asked Unity questions.

Check our Moderator Guidelines if you’re a new moderator and want to work together in an effort to improve Unity Answers and support our users.

Follow this Question

Answers Answers and Comments

No one has followed this question yet.

Related Questions

Picking up few different objects 0 Answers

Stop picked up object clipping through walls? 0 Answers

Having a RaycastHit event create a component? 1 Answer

Problem With RayCast 3 Answers

thousands of raycasts in nested for loop 0 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