The Physic Material adjusts friction and bouncing effects of colliding GameObjectsThe fundamental object in Unity scenes, which can represent characters, props, scenery, cameras, waypoints, and more. A GameObject’s functionality is defined by the Components attached to it. More info
See in Glossary.
To create a Physic Material, select Assets > Create > Physic Material from the menu bar. Then drag the Physic Material from the Project View onto a ColliderAn invisible shape that is used to handle physical collisions for an object. A collider doesn’t need to be exactly the same shape as the object’s mesh - a rough approximation is often more efficient and indistinguishable in gameplay. More info
See in Glossary in the scene.
Property: | Function: |
---|---|
Dynamic Friction | The friction used when already moving. Usually a value from 0 to 1. A value of zero feels like ice, a value of 1 will make it come to rest very quickly unless a lot of force or gravity pushes the object. |
Static Friction | The friction used when an object is laying still on a surface. Usually a value from 0 to 1. A value of zero feels like ice, a value of 1 will make it very hard to get the object moving. |
Bounciness | How bouncy is the surface? A value of 0 will not bounce. A value of 1 will bounce without any loss of energy, certain approximations are to be expected though that might add small amounts of energy to the simulation. |
Friction Combine | How the friction of two colliding objects is combined. |
- Average | The two friction values are averaged. |
- Minimum | The smallest of the two values is used. |
- Maximum | The largest of the two values is used. |
- Multiply | The friction values are multiplied with each other. |
Bounce Combine | How the bounciness of two colliding objects is combined. It has the same modes as Friction Combine Mode |
Friction is the quantity which prevents surfaces from sliding off each other. This value is critical when trying to stack objects. Friction comes in two forms, dynamic and static. Static friction is used when the object is lying still. It will prevent the object from starting to move. If a large enough force is applied to the object it will start moving. At this point Dynamic Friction will come into play. Dynamic Friction will now attempt to slow down the object while in contact with another.
When two bodies are in contact, the same bounciness and friction effect is applied to both of them according to the chosen mode. There is a special case when the two colliders in contact have different combine modes set. In this particular case, the function that has the highest priority is used. The priority order is as follows: Average < Minimum < Multiply < Maximum. For example, if one material has Average set but the other one has Maximum, then the combine function to be used is Maximum, since it has higher priority.
Please note that the friction model used by the Nvidia PhysX engine is tuned for performance and stability of simulation, and does not necessarily present a close approximation of real-world physics. In particular, contact surfaces which are larger than a single point (such as two boxes resting on each other) will be calculated as having two contact points, and will have friction forces twice as big as they would in real world physics. You may want to multiply your friction coefficients by 0.5 to get more realistic results in such a case.
The same logic applies to the bounciness model. Nvidia PhysX doesn’t guarantee perfect energy conservation due to various simulation details such as position correction. So for example when the bounciness value of an object affected by gravity is 1 and is colliding with ground that has bounciness 1 expect the object to reach at higher positions than then initial one.
PhysicMaterial
When you visit any website, it may store or retrieve information on your browser, mostly in the form of cookies. This information might be about you, your preferences or your device and is mostly used to make the site work as you expect it to. The information does not usually directly identify you, but it can give you a more personalized web experience. Because we respect your right to privacy, you can choose not to allow some types of cookies. Click on the different category headings to find out more and change our default settings. However, blocking some types of cookies may impact your experience of the site and the services we are able to offer.
More information
These cookies enable the website to provide enhanced functionality and personalisation. They may be set by us or by third party providers whose services we have added to our pages. If you do not allow these cookies then some or all of these services may not function properly.
These cookies allow us to count visits and traffic sources so we can measure and improve the performance of our site. They help us to know which pages are the most and least popular and see how visitors move around the site. All information these cookies collect is aggregated and therefore anonymous. If you do not allow these cookies we will not know when you have visited our site, and will not be able to monitor its performance.
These cookies may be set through our site by our advertising partners. They may be used by those companies to build a profile of your interests and show you relevant adverts on other sites. They do not store directly personal information, but are based on uniquely identifying your browser and internet device. If you do not allow these cookies, you will experience less targeted advertising. Some 3rd party video providers do not allow video views without targeting cookies. If you are experiencing difficulty viewing a video, you will need to set your cookie preferences for targeting to yes if you wish to view videos from these providers. Unity does not control this.
These cookies are necessary for the website to function and cannot be switched off in our systems. They are usually only set in response to actions made by you which amount to a request for services, such as setting your privacy preferences, logging in or filling in forms. You can set your browser to block or alert you about these cookies, but some parts of the site will not then work. These cookies do not store any personally identifiable information.