Remember me

Register now!
H3D.org Feeds

Browsing this Thread:   1 Anonymous Users

Difference between HapticShapeConstraint and HapticSpring
#1
Not too shy to talk

Hi
The document which described the force (HapticShapeConstraint) calculated is a spring force.

Thus, I want to know the difference between this force effect and the HapticSpring effect. After all, the HapticShapeConstraint can be used to simulate the contact force effect.

Many thanks

Posted on: 2016/3/9 10:29

Re: Difference between HapticShapeConstraint and HapticSpring
#2
Webmaster

The difference is that HapticSpring effect is a force effect which will only calculate a spring force towards a point.

Whereas the HapticShapeConstraint will calculate a spring effect towards the closest point (to the haptic device position) on any HAPI::Collision::CollisionObject (for example a bunch of triangles). If the haptic shape that is given is just a point then this force effect will behave the same as a HapticSpring.

Just to be clear, these are the ones I am referring to:
HapticSpring
and
HapticShapeConstraint

Posted on: 2016/3/9 15:17

Re: Difference between HapticShapeConstraint and HapticSpring
#3
Not too shy to talk

I am sorry I confused with HapticShapeConstraint and HapticPrimitive. Actually, I want to know the difference between HapticPrimitive and HapticSpring.

How do you achieve the HapticPrimitive effect? Is it still a spring effect or different one?

I cannot find relevant information from HapticPrimitive

Thank you.

Posted on: 2016/3/9 17:22

Re: Difference between HapticShapeConstraint and HapticSpring
#4
Webmaster

I assume you are working with HAPI directly and not H3DAPI at all? If you are using H3DAPI then simply add a SmoothSurface to your appearance.

If you work with HAPI directly then look at the example in examples/HAPI/SurfaceExample to see how a HapticPrimitive is used. It is not inheriting from the HAPIHapticsEffect and is therefore not considered a spring effect. The device is required to have a haptics renderer set, for example RuspiniRenderer. Exactly how that algorithm work you can find out by going to the paper referred to in the RuspiniRenderer.h.

Internally the forces are calculated using a stiffness constant, and the final force is calculated in a similar way to a spring force yes, by multiplying a vector with a scalar.

[EDIT] btw, the link is now fixed. Thanks for the report.

Posted on: 2016/3/10 7:42

Re: Difference between HapticShapeConstraint and HapticSpring
#5
Not too shy to talk

Thank you for your help, I understand now.

Posted on: 2016/3/10 12:59

You can view topic.
You cannot start a new topic.
You cannot vote in polls.
You cannot attach files to posts.
You cannot post without approval.
You cannot use topic type.
You cannot use HTML syntax.
You cannot use signature.
You cannot create pdf.
You cannot get print page.