Cineversity

Hi Folks;

I have always been confused by what I can and can’t do with the Broadcast Version simulation system. A specific question I have is can I drive a *gear* system with the new R16 version with the Broadcast sim tags or do I need to have the full studio version? I have tried and can’t seem to do it, but that just may be me setting it up incorrectly. 

Cheers
Steve

Hi Steve,

As far as I know there is no limitation for that part, but I can’t find an updated comparison chart at the moment. So, my answer has to remain a little bit blurry for now.

However, if you like to set up a Cogwheel scene, I would not even bother to do it with any “Dynamic System”. I think it is faster with XPresso, and from my point of view even simpler.

I have seen people telling you need to do the math with the size and such. Well, that works, but as you will set the “wheels” anyway in a correct position to each other, the number of teeth on each wheel is the only thing that really matters. Having said that, this is then easily to set up in XPresso.
My personal way of doing it, is based on that each wheel is a child of a Null Object, so I can adjust the “fit” to each. Once it is set up, it works without calculation, and very fast!

If you have a small scene, please share and I set it up for you.

All the best

Sassi

Hi Dr. Sassi

Very generous offer, thanks for making it. I haven’t created the scene just yet, I wanted to see if I could drive the chain of gears with a single gear and dynamics. Never thought to use expresso (probably because I don’t understand it). When I create the scene I will pass it on.

But I do have a question. I understand how the dynamics would work, basically a single gear drives the rest of the gears as rigid bodies but would the espresso simulate that action, (for example simulate rotational timing or actually recreate the same *dynamic* movement just done programmatically) just curious. 

Cheers
Steve

Hi Steve,

The Dynamic solution would have the need to be very precisely set up in terms of hierarchy with all elements. The first element must be calculated first, then the second, etc. If that logic is not consistent through the chain of actions, I would expect some kind of trouble. If that is for a production, I would make is as safe as possible.

I have attached a scene file with three cogwheels. I used here the smallest element in XPresso to calculate something. The “$1” stand for the input. The negative is needed for every second element to change the rotation direction. Then you can see that I just did the tooth-math.

As any element in a change is dependent on the initial element, I do not create a chain of calculations., to keep it clean.

If you change the R.B. (see image) of the first Null object 9not the cogwheel), then it should work fine.

If you like to do a gear box or a clock, then you find that there are often two cog-wheels connected on one axis, but with different amount of teeth and diameter. This twin wheel that branches the rotation to a new line, is then the starting point of a new XPresso Node, as from there the rotation speed might change. Hence the idea of a gear box to change speed in the first place.

If the chain of elements needs that little imprecision, the gap between the teeth of two elements, a little bit more work is needed, perhaps a memory node to have that established.

I talk here about preparation for animation, for a rendering. There is my target and ideas.

All the best
Sassi

P.S., the file is r15 as I was not certain which version you have already installed.

Hi Dr. Sassi,

This is awesome! Exactly what I was looking for. Much simpler than using dynamics.  Thank you for your time and expertise !

Cheers
Steve

Thanks for the nice feedback, Steve.

Let me know if there is any question, I’m happy to ahve a look into it.

My best wishes

Sassi