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Technical Discussion » Does the Copy SOP not propagate groups?
- DASD
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Houdini Indie and Apprentice » Multiparm Block (list) has bug when nesting?
- DASD
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Thank you awong! This makes things clear!
Two questions remain for me:
1: Would it not make sense to have a variable specifically for the second list number? - Something like “#2”.
And then you could (theoretically) go even further and nest a list in the second list. This third list could then be represented by “#3” and so on.
2: How would you call a nested multi-block parameter from within a loop?
(So in the example above, I would have a loop running as often as the amount of curves I have and in that loop I would have a loop that would run as often as the amount of points in that curve. And each point could then be influenced by the value in the relevant parameter and be part of some complex operation.)
Two questions remain for me:
1: Would it not make sense to have a variable specifically for the second list number? - Something like “#2”.
And then you could (theoretically) go even further and nest a list in the second list. This third list could then be represented by “#3” and so on.
2: How would you call a nested multi-block parameter from within a loop?
(So in the example above, I would have a loop running as often as the amount of curves I have and in that loop I would have a loop that would run as often as the amount of points in that curve. And each point could then be influenced by the value in the relevant parameter and be part of some complex operation.)
Technical Discussion » Does the Copy SOP not propagate groups?
- DASD
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Turn your groups into attributes before you copy. Make sure the attribute gets transferred by the copy node and then group based on the attribute.
Houdini Indie and Apprentice » Composite frames into a grid
- DASD
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Probably would need to create a kind of loop with transformation in VOP COP2.
In qLib (https://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&p=192014) [sidefx.com] they have a node called “tile loader”. If it does not do what you are trying to do, it should at least give you a pretty good start.
In qLib (https://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&p=192014) [sidefx.com] they have a node called “tile loader”. If it does not do what you are trying to do, it should at least give you a pretty good start.
Houdini Lounge » Sort Prim Number by Color
- DASD
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As far as I understand, your only problem is that your sorting order gets recomputed every frame.
You can sort by an expression and you can add (and manipulate) additional attributes per frame to keep track of your previous sorting order.
You can sort by an expression and you can add (and manipulate) additional attributes per frame to keep track of your previous sorting order.
Technical Discussion » Linked Channels vs Channel Reference
- DASD
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As far as I am aware, there is no difference. Rather, you would refer to a parameter with something like ch(..) and the linking automatically keeps things updated if you rename something.
I think you can break the link (and prevent it from creation) to prevent the automatic update of parameters when you rename a node or parameter.
- Not sure about any of this.
I think you can break the link (and prevent it from creation) to prevent the automatic update of parameters when you rename a node or parameter.
- Not sure about any of this.
Technical Discussion » Boolean Modelling Resources for Houdini
- DASD
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I'm totally Looking forward to the tool improvements.
A neat trick with the clip tool, is to use its group parameter so that it only affects the relevant area.
A neat trick with the clip tool, is to use its group parameter so that it only affects the relevant area.
Houdini Engine for Unreal » Curve to UE4 workflow
- DASD
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Thank you!
1. Method 1 seems to work for me. Operator path parameters
2. I think the part that specifically does not seem to work are parameters of the type:
Operator Path
Maybe I just don't know how to correctly specifiy the string for these operators inside of Unreal. But I guess they are just not supported?
- I would expect them to work exactly like a Static Mesh Instance mesh slot, that is by default empty. And then I would use a multiparm block list (of Operator Path parameters) to control the amount of mesh inputs I need.
I realize this could be achieved with a Static Mesh Instance mesh slot, but then I don't have any control over multiple entries in one slot (because they get assigned randomly). Am I missing something?
1. Method 1 seems to work for me. Operator path parameters
2. I think the part that specifically does not seem to work are parameters of the type:
Operator Path
Maybe I just don't know how to correctly specifiy the string for these operators inside of Unreal. But I guess they are just not supported?
- I would expect them to work exactly like a Static Mesh Instance mesh slot, that is by default empty. And then I would use a multiparm block list (of Operator Path parameters) to control the amount of mesh inputs I need.
I realize this could be achieved with a Static Mesh Instance mesh slot, but then I don't have any control over multiple entries in one slot (because they get assigned randomly). Am I missing something?
Houdini Indie and Apprentice » Multiparm Block (list) has bug when nesting?
- DASD
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So I am trying to nest “Multiparm Block (list)”s and the default values are not what I would expect.
Example attached.
What I would expect:
# gives the number of the parameter in the first list
#_# gives the number of the parameter in the first nested list
So in my example
first point on the first curve would have the default value 1, 1, 0
seccond point on the first curve would have the default value 2, 1, 0
first point on the seccond curve would have the default value 1, 2, 0
etc.
Also, if you do simple math with the #_# it seems to bug out completely. Try putting #_#-#*10 into the default value and try adding and removing curves and points. Watch it break in unexpected ways.
Am I doing it wrong? Is multiparm block list nesting not supported or broken?
P.S. I think there is a lot of use for this technique and I am surprised by how little information there is on the topic of multiparm blocks (not to mention multiparm block nesting).
Example attached.
What I would expect:
# gives the number of the parameter in the first list
#_# gives the number of the parameter in the first nested list
So in my example
first point on the first curve would have the default value 1, 1, 0
seccond point on the first curve would have the default value 2, 1, 0
first point on the seccond curve would have the default value 1, 2, 0
etc.
Also, if you do simple math with the #_# it seems to bug out completely. Try putting #_#-#*10 into the default value and try adding and removing curves and points. Watch it break in unexpected ways.
Am I doing it wrong? Is multiparm block list nesting not supported or broken?
P.S. I think there is a lot of use for this technique and I am surprised by how little information there is on the topic of multiparm blocks (not to mention multiparm block nesting).
Edited by - Jan. 21, 2016 07:47:26
Houdini Learning Materials » Sharing my tutorials
- DASD
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Houdini Engine for Unreal » Curve to UE4 workflow
- DASD
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To 1.
A great Houdini-level work-around would be if we had a curve parameter. It could be something similar to the add node, where you can add and remove unlimited amounts of points.
Edit: - I just saw that the add node uses a “Multiparm Block (list)” parameter and it seems to work in UE4. So that could be turned into a sufficient work-around.
To 2. Basically I just export a thin polygon strip. Because UE4 does not seem to import NURBS curves or (Houdini) polygon lines. I can convert that thin polygon strip into a curve inside the HDA.
My actual question should be: How exactly do I get geometry into the HDA inside of UE4?
I think a good work around for this would be to create an asset with a curve, instantiate it, and then in your asset use that curve asset as an input asset.I'm not entirely sure I understand. How would I implement curves of varying amounts of CVs?
A great Houdini-level work-around would be if we had a curve parameter. It could be something similar to the add node, where you can add and remove unlimited amounts of points.
Edit: - I just saw that the add node uses a “Multiparm Block (list)” parameter and it seems to work in UE4. So that could be turned into a sufficient work-around.
To 2. Basically I just export a thin polygon strip. Because UE4 does not seem to import NURBS curves or (Houdini) polygon lines. I can convert that thin polygon strip into a curve inside the HDA.
My actual question should be: How exactly do I get geometry into the HDA inside of UE4?
Houdini Engine for Unreal » Curve to UE4 workflow
- DASD
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Hi,
This should be fairly straight forward, but I have a few issues:
1. I can create a Polygon curve on the HDA in UE4 under Houdini Inputs, but how would I feed that into a (Operator Path) parameter?
2. I can create a polygon that has the curve shape and import that into UE4 via FBX. How would I feed that into a (Operator Path) parameter?
This should be fairly straight forward, but I have a few issues:
1. I can create a Polygon curve on the HDA in UE4 under Houdini Inputs, but how would I feed that into a (Operator Path) parameter?
2. I can create a polygon that has the curve shape and import that into UE4 via FBX. How would I feed that into a (Operator Path) parameter?
Houdini Engine for Unreal » Multi-segment curves in Unreal
- DASD
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Hi, I don't seem to have the crash, but how do I feed a curve I created in UE4 (in a HDA under Houdini Inputs) into an input paramater (on the same HDA)?
Technical Discussion » visualizers, and the dreaded triplicate form
- DASD
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True, didn't check that.
-But I see that it is a (fairly simple) digital asset. Dive into it and change it according to your needs. That is, if SideFX doesn't fix it.
{edit: You will probably want to work with a copy.}
-But I see that it is a (fairly simple) digital asset. Dive into it and change it according to your needs. That is, if SideFX doesn't fix it.
{edit: You will probably want to work with a copy.}
Technical Discussion » visualizers, and the dreaded triplicate form
- DASD
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Two things:
Even if SideFX were not to fix this, you could use expressions to copy the string from the input into the other fields. You could then make that the default preset for the node and never worry about it again.
Because I work a lot with locking nodes, I was sad to see it gone. But I put the function on a custom hotkey and it works perfectly.
Even if SideFX were not to fix this, you could use expressions to copy the string from the input into the other fields. You could then make that the default preset for the node and never worry about it again.
Because I work a lot with locking nodes, I was sad to see it gone. But I put the function on a custom hotkey and it works perfectly.
Houdini Indie and Apprentice » bevel problem
- DASD
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You will probably have to look into straight skeletons: https://en.wikipedia.org/wiki/Straight_skeleton [en.wikipedia.org]
- There is useful info on that in other forum posts.
In H15 polyextrude with active limit and positive inset value gives good results. You might need to update your Houdini build, because there were some bug-fixes on the polyextrude since official release. There are still situations where it bugs out, but they can probably be solved with some clever selecting and deleting or raying.
Also worth considering would be to start from the cusp (use curves without thickness to shape the letters) and use polyexpand 2D. Then move and extrude the polyexpanded shape. Then ray the extruded front to the original curve by closest distance. Or something like that.
- There is useful info on that in other forum posts.
In H15 polyextrude with active limit and positive inset value gives good results. You might need to update your Houdini build, because there were some bug-fixes on the polyextrude since official release. There are still situations where it bugs out, but they can probably be solved with some clever selecting and deleting or raying.
Also worth considering would be to start from the cusp (use curves without thickness to shape the letters) and use polyexpand 2D. Then move and extrude the polyexpanded shape. Then ray the extruded front to the original curve by closest distance. Or something like that.
Houdini Indie and Apprentice » bevel problem
- DASD
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Technical Discussion » Orienting instanced geometry to primitive centroid
- DASD
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Currently the most efficient method to get the center of a primitive seems to be to use an Attribute Wrangle set to “Run Over: Primitives” with the following code:
addpoint(0, @P);
removeprim(0, @primnum, 1);
First line adds a point to the center of each primitive. (I believe it uses the point average for the center).
The second line is optional and removes the original primitives.
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Add an attribute SOP and create an “up” Vector attribute with value something like 0,1,0.
Then use a point VOP to get the vector from each point to wherever you want the object to rotate to. (Goal point minus start point equals vector from goal to start). Normalize that and bind export as the normal attribute “N”.
Feed that into copy and or instance SOP and you get what you want.
addpoint(0, @P);
removeprim(0, @primnum, 1);
First line adds a point to the center of each primitive. (I believe it uses the point average for the center).
The second line is optional and removes the original primitives.
-
Add an attribute SOP and create an “up” Vector attribute with value something like 0,1,0.
Then use a point VOP to get the vector from each point to wherever you want the object to rotate to. (Goal point minus start point equals vector from goal to start). Normalize that and bind export as the normal attribute “N”.
Feed that into copy and or instance SOP and you get what you want.
Houdini Indie and Apprentice » random in Foreach
- DASD
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https://vimeo.com/142534639 [vimeo.com] - watch this.
In the old foreach SOP the expression was soemthign like: stamp(“..”,“FORVALUE”,0).
In the new foreach you will need a wired metadata node and you get the iteration number with detail(“../metanode”,“iteration”,0)
In the old foreach SOP the expression was soemthign like: stamp(“..”,“FORVALUE”,0).
In the new foreach you will need a wired metadata node and you get the iteration number with detail(“../metanode”,“iteration”,0)
Houdini Learning Materials » How a 3D workflow works
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You can teach yourself, but a good formal education gets you to a much higher level much faster. There are differences between people, though. Some can learn on their own with online tutorials and forums and whatnot. - in fact you will do the same in a formal education, but you get more structure from teachers and assignments.
Personally I tried to teach myself for about a year, then went to IGAD NHTV in the Netherlands. Was there for 4 years to get my degree. Even though I already knew some stuff, it was really tough. Now, I'm still learning new stuff practically every day.
It is very difficult to find a good education in the field. Many CG school are little better than scams, because they don't really teach you useful skills and are very expensive. Anyways, you will want to find a school that focuses almost entirely on practice and project work, has a curriculum with strong focus on the field that actually interests you, is not expensive (because you might not find a job afterwards anyways, or decide to abort the study) and has a good reputation for putting out skilled students. If you go that route I highly recommend to invest time into properly researching the right school for you.
Personally I tried to teach myself for about a year, then went to IGAD NHTV in the Netherlands. Was there for 4 years to get my degree. Even though I already knew some stuff, it was really tough. Now, I'm still learning new stuff practically every day.
It is very difficult to find a good education in the field. Many CG school are little better than scams, because they don't really teach you useful skills and are very expensive. Anyways, you will want to find a school that focuses almost entirely on practice and project work, has a curriculum with strong focus on the field that actually interests you, is not expensive (because you might not find a job afterwards anyways, or decide to abort the study) and has a good reputation for putting out skilled students. If you go that route I highly recommend to invest time into properly researching the right school for you.
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