# switching between 2 mdds based on height or slope

• 11-27-2017, 03:19 PM
marchermitte
switching between 2 mdds based on height or slope
Hello there.
I have 2 mdds of a character, one running and one climbing
I'd like to pilote instances of a character (to create a crowd) based on their height so that they run on the flat floor and they climb on the slope .

I tried using logic nodes and gradient based on y distance or slope... but I'm stuck.

So my first question is: is there a way to dispatch two (or more) mdds over a population of instance? Can instances be connected to mdds?
And if so, any hint on how I could hook the node network up for that result?

Thank you very much
• 11-27-2017, 05:20 PM
Sensei
You're probably one of many people who don't understand how instances work.

Imagine you have some object, in the real world, not 3D,
around this object there are placed cameras,
these cameras record what object is doing.

Then whatever object is doing is replicated.

That's how instances works.

Matrix transformation.

If you apply MDD to object,
then instance it,
the all instances will get the same MDD..
In fact they are the same object as their reference from math point of view, just after vector multiplication by matrix (4x4).

There is possible different instancing algorithm, were object is literally duplicated, and then local matrix is applied.. But that's not LW instancing..
It's memory hungry algorithm.
• 11-28-2017, 02:55 AM
marchermitte
Thank you Sensei... you're always answering so fast and effectively!
There are more things than instances that I don't understand :-)
More seriously, I thougt It might be impossible and I get It, instances are just like... say hologramm of one reference mesh. So I guess I would have to create two reference meshes with specific MDDs THEN find a way to create instances of the running character on the floor and instances of the climbing character on the slopes. (which is very easy with gradient on the weight input of each instance)
But I won't be able to have the same instance switching from running mdd to climbing mdd.
I remember the HDinstance plugin that allowed to randomise some of the motion (speed / offset etc) and Modo instances can also be randomised but It takes so long to render, which illustrates your point about memory I guess.