Connecting Attributes

[Rafal123]

Example in Maya:

I got few hundreds od particle emitters. Now I create locator/null, add new attribute to it, i.e Scale, and then connect one attrubute from each particle emitter to new Scale attribute in locator/null. So I can control all of them using this one new attribute.

I wanna do something like that in Houdini but my problem is I don't know how to 'get' those attributes. I mean, in Maya I see all Mel stuff, so I can just cut it and paste where I want.

Can you explain how to do it in Houdini?

[Visual Cortex Lab]

If I correctly understood... isnt just a point SOP after each POP with a scale attribute set to get the "scaling" from the Null?

I might be wrong tought..

[TheUsualAlex]

Example in Maya:

I got few hundreds od particle emitters. Now I create locator/null, add new attribute to it, i.e Scale, and then connect one attrubute from each particle emitter to new Scale attribute in locator/null. So I can control all of them using this one new attribute.

I wanna do something like that in Houdini but my problem is I don't know how to 'get' those attributes. I mean, in Maya I see all Mel stuff, so I can just cut it and paste where I want.

Can you explain how to do it in Houdini?

24898[/snapback]

Hi,

Houdini has Attributes too. There are various types: Point, Primitive, Vertex, and Detail attribute. Point attributes are probably most often used and can be passed downstream whenever you created. You can access value of a point attributes of another node via point(). Primitive attributes are attached at primitive level, or per face, and can be acessed via prim(). And so forth.

To create attributes, use AttribCreate SOP. You can see what attribute value you have via spreadsheet. You can see what attribute you have when you MMB on a node. It should be pretty straight forward. This is pretty much how you "attach" attributes in Houdini.

HTH,

Alex

[michael]

this sounds different to me...

in Maya, attributes are things like tx etc

so it sounds like you want to create a new /parameter/ and use that to control other parameters...no?

have a look at the Property POP, you can put an expression inthere referencing your created Scale parameter...

HTH

[Rafal123]

thanks for answers guys

it was just an example, what I wanted is to create one attribute(variable?) to which I can connect many others attributes(the same type) and then use this ONE attribute/variable to control them all,

maybe lights could be better example:

so I wanna in Houdini create 500 lights, something like dome_light, I don't wanna spend half a day to setting their intensity, so my idea is to create one SPECIAL attribute on simple node like i.e NULL and connect 'dimmer' attribute from all these lights to new attribute, let's call it 'INTENSITY' in NULL,

anyway, thanks for info

maybe my way of solving this type of problem is strange so if U got some ideas please free to share

[michael]

I linked the Uniform Scale of the null called Dimmer_Control

to the Dimmer parameter of all the lights

now you can control one many parameters with just the one....

is this the kind of thing you are looking for?

dimmer_control.hip

[sibarrick]

That's even easier. Here's 3 suggested ways

Use an otl either with all your lights inside and all linked to a control on the front.

or

Create a spare channel on your special null object and create a channel reference to it in all the other nodes. Just RMB copy parameter, select all the lights and RMB paste reference.

or

Create a global variable using the alias and variables ui under the settings menu. for example add a variable called DIMMER then select all your lights and type $DIMMER in the channel you want to control.

The downside then is you can't animate it.

Is that what you meant?

[Rafal123]

hey guys, thanks for answers

Arctor: maybe this is not exactly what I wanted but....hmm, it works well, many thanks

Sidbarrick: I don't have an experience with OTL yet , I must check it, heey... spare_channel on NULL is the way to go, yeahh this is it, thanks man