View Full Version : What can read what in Layout?

02-16-2017, 02:20 PM
maybe this should be in the support forum, but I am looking more for some general guidelines than a way to solve a particular problem, so I am putting it here.

I am trying to solve a simple issue. I am trying to get a null that is moved using nodal motion to drive the dissolve channel of another object using cycler, and I cannot for the life of me get it to work. I have tried it strait up and that didn't work so I tried to apply a motion baker modifier to the null to capture the motion, but it still doesn't work.

The nodal motion modifier moves the null along the y, and I can see the null moving like it should, but the channel remains at 0 as far as cycler or motion baker is concerned. I have tried using motion baker to bake to the Existing y channel or an extra channel. No dice. I have toggled after IK in the nodal motion on and off with no effect.

Is there a good rule of thumb to follow when figuring out what can read what. what data can channel modifiers read?

update. Ok if I use a null in between it seems to work. so an extra null with the nodal motion, and then the null with motion baker that the dissolve channel reads is constrained to that node using same as item.

Still not sure what the rule is, though.

02-16-2017, 02:51 PM

02-16-2017, 03:12 PM
It doesn't really answer the answer of "what can read what" (evaluation order), but you might be able to copy your nodal calculation graph into the Dissolve=>Envelope=>Modifiers=>Textured Channel=>Procedural=>Node Editor and eliminate the Null Y-Position middle-man.

First, get into the Nodal Motion editor for the Null, drag-select the nodes which calculate the Y position, right-click and select Copy. Then, for the object to be dissolved, click the Render tab=>Dissolve Envelope button and in the Graph Editor's Modifiers tab, add Textured Channel (removing or disabling Cycler). Double-click Textured Channel to bring up the options, and click the Texture button. Select Procedural Texture, and from the Procedural Type pull-down, select Node Editor (just above Turbulence). Set the Texture Value to 1.0, then click Edit Nodes. Right-click anywhere and select Paste. Adjust your nodal calculation if required.

Hope it works for you!


02-16-2017, 04:04 PM
Thanks for the help.
RH, that is exactly what I was looking for.
Mtp, I will have to try the nodal texture channel modifier trick to see if that works. I would rather not have to use motion baker if I can help it.

One more question, what are the rules concerning multiple motion modifiers. In what order are they evaluated? Or are multiple motion modifiers just a bad idea.

02-16-2017, 04:21 PM
Stacks evaluate top to bottom. As for channel modifiers (cant remeber if I mention it explicitly in the vid or not, but if u think through the details, u can see its implied at least)... channel mods work OVER the recorded keyframe values present in the channel, if you set a control via nodes, or constraints, or whatever else, then that data is not present in the channel (as actual keys), ergo, channel mods cant operate atop it... plus, since they evaluate after keyframing, they'd be overridden by other constraints further down the pipe.

It doesn't really answer the answer of "what can read what" (evaluation order)

It does... anything can (technically speaking) read anything else... the determining factor of how one "area" reads the content of another, is the order in which they're evaluated... evaluation order is the ONLY answer to the question.

02-16-2017, 11:53 PM
Got it, Thanks! The reason I was asking about the evaluation order of motion modifiers in the stack is that motion baker wouldn't write key frame data based on the motion modifier (nodal motion) above it. But it would bake the motion if it was passed through another null using same as item. I guess maybe Motion baker only writes keys for motion that is has been evaluated by IK level stuff?

02-17-2017, 04:43 AM
use this guy...