Can I customize the particle orientation using Edem API

Hi,

Depends what you mean. You could use a custom factory to make them start in whatever orientation you like, though you can do similar in a regular factory without the API.

If you mean mid simulation, then yes - kind of - but you can't explicitly set the orientation in the API, you would need to back calculate it from an appropriate force/torque. The same concept, but with velocity, is mentioned in this post:

https://community.altair.com/community?id=community_question&sys_id=b219e5811bd59d14507ca6442a4bcb8b&anchor=answer_88763c761b1dd954507ca6442a4bcbad

Cheers,

Richard

 

The random orientation is not truly random. I am trying to generate a bunch of particles and i have kept the orientation random but whenever the meta-particles get generated it is slightly biased in one direction why is ti so? Is there a workaround? can the orientation be set to a truly random number through an API at the beginning when the particle is generated? 

Please see the image below

There is some kind of a bias

why are there very less particles in y direction? i don't have too many constraint for factory generation the dimensions of the factory is 300*300 sq units Which is ample room to have a lot more orientations.

How to get a truly random orientation?

The random orientation is not truly random. I am trying to generate a bunch of particles and i have kept the orientation random but whenever the meta-particles get generated it is slightly biased in one direction why is ti so? Is there a workaround? can the orientation be set to a truly random number through an API at the beginning when the particle is generated? 

Please see the image below

There is some kind of a bias

why are there very less particles in y direction? i don't have too many constraint for factory generation the dimensions of the factory is 300*300 sq units Which is ample room to have a lot more orientations.

How to get a truly random orientation?

Hi,

I'd say that's not a huge sample size but I get your point - it certainly looks like it has a bias based on that sample. At first glance it doesn't look totally random but I'd maybe leave it running just to double check? Is it the same when looking along X and Y axes as well?

I couldn't tell you our implementation off the top of my head so it would require some investigation on our side.

In the mean time, if you did want to do a more random distribution (you will never get true random in code, without external input of some nature) you could write a custom factory using the API, where you can control the orientation. Alongside that, it's up to you what random number generator you want to use.

Cheers,

Richard

The random orientation is not truly random. I am trying to generate a bunch of particles and i have kept the orientation random but whenever the meta-particles get generated it is slightly biased in one direction why is ti so? Is there a workaround? can the orientation be set to a truly random number through an API at the beginning when the particle is generated? 

Please see the image below

There is some kind of a bias

why are there very less particles in y direction? i don't have too many constraint for factory generation the dimensions of the factory is 300*300 sq units Which is ample room to have a lot more orientations.

How to get a truly random orientation?

I just did my own meta particle random test and it seems fine to me:



Are you sure there's plenty of room for it to be oriented in all those different orientations? I could see how in a very small volume that there would only be a limited number of orientations possible

Please let me know how to write a custom factory?

I looked for examples in knowledge Base and couldn't find any examples for a API of custom factory to give orientation

Please let me know how to write a custom factory?

I looked for examples in knowledge Base and couldn't find any examples for a API of custom factory to give orientation

Never mind i found it EDEM tutorial 6 is for custom factory. 

I have a question about that API now. suppose i want to use that API to create particles of different orientations and random positions.

If there is any particle already present in that random position I pick how will I make the API skip that position? How can I check for the presence of another particle at that position? is there any inbuilt command for that?Please let me know

I only want to create particles with the API in the initial step only after that i don't want to control its position

 

Also can you create meta particles with this factory? because i get this error

 

Also can you create meta particles with this factory? because i get this error

 

Hi,

No, currently you can only place 'regular' particles. You can recreate the same behaviour as a meta-particle through a custom factory and bond the particles after creation, but it's a bit of work to do so. This is essentially what meta-particles are though.

Cheers,

Richard