Yeah, I don't know how I missed this. I've actually done it before! I did a test and I ended up with an unexpected result.
Thanks for the response.
-Judah
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Technical Discussion » ObjectMerge Globbing?
- judahbaron
- 9 posts
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Technical Discussion » ObjectMerge Globbing?
- judahbaron
- 9 posts
- Offline
I am looking for a way to glob object data, similar to how the fetch CHOP node works.
I see that it's possible to add multiple objects in the ObjectMerge node, but that must be done explicitly. I need to pull objects in more procedurally.
Thanks.
-Judah
I see that it's possible to add multiple objects in the ObjectMerge node, but that must be done explicitly. I need to pull objects in more procedurally.
Thanks.
-Judah
Technical Discussion » Multi object/channel CHOP Structure question.
- judahbaron
- 9 posts
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Hi friedasparagus (is that is indeed your name - Henry),
This is just what I was looking for. It works exactly as expected.
By the way, on another topic, your instructional videos have been quite helpful. We are in the process of evaluating Houdini as a rigging alternative. I see some great potential, but I'm still not familiar enough with it to see the complete pipeline.
Today, just about anything can be considered a real word. I don't think “globbable” is much of a stretch, though it does offer some humor
Thanks again for the example file. Super helpful.
-Judah
This is just what I was looking for. It works exactly as expected.
By the way, on another topic, your instructional videos have been quite helpful. We are in the process of evaluating Houdini as a rigging alternative. I see some great potential, but I'm still not familiar enough with it to see the complete pipeline.
Today, just about anything can be considered a real word. I don't think “globbable” is much of a stretch, though it does offer some humor
Thanks again for the example file. Super helpful.
-Judah
Technical Discussion » Multi object/channel CHOP Structure question.
- judahbaron
- 9 posts
- Offline
I am looking for a way to drive the transform components of multiple objects with a single CHOP network if possible. I am currently using a fetch node to gather input channels and an export node to direct the resultant output. The problem I'm running into is that the fetch and export nodes order the channel data differently. For example, setting up the fetch to bring in t r & z delivers the expected channels, ordered as expected: channels grouped by object first, then component. But the export node does not respect or maintain that order. Instead, export jumbles the channels, ordering by component instead of object. This is what the mapping looks like:
object01.tx –> object01.tx
object01.ty –> object02.tx
object01.tz –> object03.tx
object02.tx –> object01.ty
object02.ty –> object02.ty
object02.tz –> object03.ty
object03.tx –> object01.tz
object03.ty –> object02.tz
object03.tz –> object03.tz
To get around this I have created a single CHOP network to handle each component individually: There is a CHOP network for tx, one for ty, one for tz, etc. This is rather bulky and seems less efficient than using a single network. Is there a better way to do this?
Thanks,
-Judah
object01.tx –> object01.tx
object01.ty –> object02.tx
object01.tz –> object03.tx
object02.tx –> object01.ty
object02.ty –> object02.ty
object02.tz –> object03.ty
object03.tx –> object01.tz
object03.ty –> object02.tz
object03.tz –> object03.tz
To get around this I have created a single CHOP network to handle each component individually: There is a CHOP network for tx, one for ty, one for tz, etc. This is rather bulky and seems less efficient than using a single network. Is there a better way to do this?
Thanks,
-Judah
Technical Discussion » Hierarchy Manipulation (Bug?)
- judahbaron
- 9 posts
- Offline
My bad. The inverter's parameters are not referencing themselves. They are referencing the handle's parameters. That was a transcription error on my part. The uploaded sample files do not have this issue. I've updated the original post to reflect the expressions accurately.
Stranger, this problem seems to be intermittent. I just loaded the file that I posted earlier and I can't reproduce the problem.
Stranger, this problem seems to be intermittent. I just loaded the file that I posted earlier and I can't reproduce the problem.
Edited by judahbaron - Jan. 16, 2018 14:57:15
Technical Discussion » Hierarchy Manipulation (Bug?)
- judahbaron
- 9 posts
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Hello,
I am coming from Maya and have a question about how Houdini handles hierarchical transformation in the context of manipulation. I'm attempting to do something that works fine in Maya, but behaves erratically in Houdini.
The hierarchy looks like this:
root/inverter/handle
The inverter has expressions on the translate channels that look like this:
tx: ch(“../handle/tx”)*-1
ty: ch(“../handle/ty”)*-1
tz: ch(“../handle/tz”)*-1
The result is intended to negate translation, so the handle appears to be stationary, but in fact it stores some offset data in the translate attributes. If the values are entered and keyed on the handle's translate properties using the parameter interface, everything works as expected.
But if the translate manipulator is used instead (dragged in the viewport), the behavior becomes erratic. It looks like there is an accumulation problem due to how manipulation is being handled.
Rather than storing an initial manipulation identity vector at the start of manipulation, it appears a new vector is calculated as long as the manipulation cycle is active and there is a non-zero delta. Consequently, there is an undesirable additive effect that makes this technique unusable: The inverter shoots off quite quickly when it should just move in the opposite direction and magnitude of the cumulative manipulation vector. It is also unwieldy in when reversing direction of the manipulator, resulting in a rather laggy and sluggish feel.
In Maya this does not happen. I'm hoping this can be considered a bug because it is a technique I use a great deal for rigging. In this example I'm using translation, but this works equally well for rotation.
Attached is a file that has 2 simple hierarchies that are set up very similarly. The only difference is that one hierarchy is built using nulls, while the other is built from geometry nodes. Other than that, the functionality is identical. Just grab one of the green rings and drag a little. Watch what happens to the red box.
Thanks.
-Judah
I am coming from Maya and have a question about how Houdini handles hierarchical transformation in the context of manipulation. I'm attempting to do something that works fine in Maya, but behaves erratically in Houdini.
The hierarchy looks like this:
root/inverter/handle
The inverter has expressions on the translate channels that look like this:
tx: ch(“../handle/tx”)*-1
ty: ch(“../handle/ty”)*-1
tz: ch(“../handle/tz”)*-1
The result is intended to negate translation, so the handle appears to be stationary, but in fact it stores some offset data in the translate attributes. If the values are entered and keyed on the handle's translate properties using the parameter interface, everything works as expected.
But if the translate manipulator is used instead (dragged in the viewport), the behavior becomes erratic. It looks like there is an accumulation problem due to how manipulation is being handled.
Rather than storing an initial manipulation identity vector at the start of manipulation, it appears a new vector is calculated as long as the manipulation cycle is active and there is a non-zero delta. Consequently, there is an undesirable additive effect that makes this technique unusable: The inverter shoots off quite quickly when it should just move in the opposite direction and magnitude of the cumulative manipulation vector. It is also unwieldy in when reversing direction of the manipulator, resulting in a rather laggy and sluggish feel.
In Maya this does not happen. I'm hoping this can be considered a bug because it is a technique I use a great deal for rigging. In this example I'm using translation, but this works equally well for rotation.
Attached is a file that has 2 simple hierarchies that are set up very similarly. The only difference is that one hierarchy is built using nulls, while the other is built from geometry nodes. Other than that, the functionality is identical. Just grab one of the green rings and drag a little. Watch what happens to the red box.
Thanks.
-Judah
Edited by judahbaron - Jan. 16, 2018 14:37:39
Technical Discussion » Difficulty with chsop()
- judahbaron
- 9 posts
- Offline
Ok, I figured this out. Digital Assets require any internal dependent parameters to be identified in “linked channels”.
Edited by judahbaron - Jan. 4, 2018 13:45:10
Technical Discussion » Difficulty with chsop()
- judahbaron
- 9 posts
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I am having some difficulty with the chsop() command when using it in an expression on a parameter of an operator within a subnet/digital asset. If I create the parameter on the subnet by dragging the parameter from the contained operator to the Edit Parameter interface it seems to work fine. But if I then attempt to reference the subnet parameter, just created, from another parameter, from that or another operator contained within the subnet, it doesn't work. The field doesn't turn green as it does on the field that is functioning as expected, and clicking on the field name doesn't toggle between the parameter value and the expression string.
I have intermittently been able to get some of these to work, but I can't identify a pattern that makes any sense. Is there something specific that determines whether this sort of connection will work or not? Is there a known issue with chsop() in expressions?
Thanks,
-Judah
I have intermittently been able to get some of these to work, but I can't identify a pattern that makes any sense. Is there something specific that determines whether this sort of connection will work or not? Is there a known issue with chsop() in expressions?
Thanks,
-Judah
Technical Discussion » Node Reference vs direct Parental Transform
- judahbaron
- 9 posts
- Offline
I am wondering if there is a performance cost associated with a node reference parameter that does not exist for direct parental transform connections. I understand that there is going to be an initial lookup cost as the scene graph is searched, but I am assuming that the result of this lookup is cached. So beyond the initial cost of finding the node specified, is there an ongoing performance cost?
Thanks,
-Judah
Thanks,
-Judah
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