I cannot get it to work via your method … also another question reguarding a Transform SOP and particles , I can pipe my sim into a copy sop and then into a transform SOP , I have a sphere piped into my copy SOP , If i emit 1 particle and then in the transfrom SOP use $ CEX , $CEY , CEZ I get a nice rotation of the ball in its z axis , if I use this with more particles its gets ignored and all the 5 particles end up rotating around there world pivot not there own local ….what gives there ? its on page 151 of will cunninghams book !
R
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Technical Discussion » impulse birth rate
- circusmonkey
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Technical Discussion » impulse birth rate
- circusmonkey
- 2624 posts
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Hi is there any way with an expression to control at which frames I want particles to birth at. I know that the impulse birth rate is on a per frame basis, so I would of thought to define a range of specific frame numbers would be pretty simple.
Can anyone point me in the right direction where to find the information?
cheers rob
Can anyone point me in the right direction where to find the information?
cheers rob
Technical Discussion » texporter
- circusmonkey
- 2624 posts
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Technical Discussion » texporter
- circusmonkey
- 2624 posts
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I was thinking along the lines of maya's script editor… for getting values. Instead of calling up various nodes via “tab” why not just script what I want to build with all its settings and run it
Rob
This program has me hooked ……
Rob
This program has me hooked ……
Technical Discussion » texporter
- circusmonkey
- 2624 posts
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Houdini Lounge » random offset for Sin waves
- circusmonkey
- 2624 posts
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adam Ive tried your solution but I cannot get it to work , do you have a simple file I could look at , grid , sphere , copy stamp ?.
I was thinking along the lines of just have the 1 sin wave then somehow offsetting when and where the the objects start moving along the sin wave maybe using there object ID to drive this.
A slight update using the copy SOP stamp with this expression in the X or Y values
varible1 sin(($F*2) + ($PT*2))
varible2 sin(($F*2)*3 + ($PT*5))
I get a nice movement still a bit to uniform , but at least it works ! would it be possible to add some noise into these expressions using noise(x,y,z) certainly interested in thoughts
R
I was thinking along the lines of just have the 1 sin wave then somehow offsetting when and where the the objects start moving along the sin wave maybe using there object ID to drive this.
A slight update using the copy SOP stamp with this expression in the X or Y values
varible1 sin(($F*2) + ($PT*2))
varible2 sin(($F*2)*3 + ($PT*5))
I get a nice movement still a bit to uniform , but at least it works ! would it be possible to add some noise into these expressions using noise(x,y,z) certainly interested in thoughts
R
Houdini Lounge » random offset for Sin waves
- circusmonkey
- 2624 posts
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An update ….
what I have done is to get a correct motion is to use a transform SOP and create a Sin expression on the X axis and the Z axis , this works much better than the bend SOP. this way I can have the sin wave work in both X and Y.
Now I would like to use stamp function in the copy SOP ,to randomly apply this sin wave to all my copies created .
I have tried sin($FF*3)*10) it works fine in the Copy sop (stamp) but all the copies move togeather. I have also tried sin($FF*(rand(123)))*10) , again it worked but all the copies get the same motion from the sin wave.
cheers R
what I have done is to get a correct motion is to use a transform SOP and create a Sin expression on the X axis and the Z axis , this works much better than the bend SOP. this way I can have the sin wave work in both X and Y.
Now I would like to use stamp function in the copy SOP ,to randomly apply this sin wave to all my copies created .
I have tried sin($FF*3)*10) it works fine in the Copy sop (stamp) but all the copies move togeather. I have also tried sin($FF*(rand(123)))*10) , again it worked but all the copies get the same motion from the sin wave.
cheers R
Houdini Lounge » random offset for Sin waves
- circusmonkey
- 2624 posts
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I am looking at creating a sin random value to a sign wave inside a bend op, with primary axis set to X
using sin ($FF *3 )*12
This works fine , now is there a way to also have it moving in Y at the same time ? coupled with a rand expression , so when I use the copy stamp all my stems will be randomly moving in X and Y. I know the rand (value ) and I know a sin wave works between +1 and -1 so really I am just looking for a rand value that would off set the ($FF * ) as a starting point. If anyone could give me some pointers I would be greatfull.
Rob
using sin ($FF *3 )*12
This works fine , now is there a way to also have it moving in Y at the same time ? coupled with a rand expression , so when I use the copy stamp all my stems will be randomly moving in X and Y. I know the rand (value ) and I know a sin wave works between +1 and -1 so really I am just looking for a rand value that would off set the ($FF * ) as a starting point. If anyone could give me some pointers I would be greatfull.
Rob
Houdini Lounge » COPY SOP
- circusmonkey
- 2624 posts
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Thanks for the tip , at the moment I have a randomly spread stems ( the poly tubes ) spread over a surface , and ocilating using a sin wave in xy and zy randomly and ontop of these stems I wanted tp spread randomly sized spheres , hence this is where my problem of defining the poly on the stem comes in , Im just about to try the divide node and define a point on the top of the stem as a group. !
So far since picking up Houdini its given me back some excitment over 3d , its just the lack information in the help files , much of what Im learning seems to come from fireside chat , this board or an ex sidefx employee … but none the less Im very excited about where houdini is going !
R
So far since picking up Houdini its given me back some excitment over 3d , its just the lack information in the help files , much of what Im learning seems to come from fireside chat , this board or an ex sidefx employee … but none the less Im very excited about where houdini is going !
R
Houdini Lounge » COPY SOP
- circusmonkey
- 2624 posts
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I have a question concerning input of data though, I thought using a group SOP I could define 1 poly as my group , pipe this into my copy SOP input 2 , for my input 1 into my copy SOP Im piping a sphere in , but what ever I do I end up with 6 spheres copied to my input 2, even though the group is defined as a poly .
After looking at this and trying various fixes what ever I do to the group SOP it only seems to read groups of points , whenever I have used the edit TAB in the group SOP to try and convert points to primative group , I get the RED play arrow.
regards R
After looking at this and trying various fixes what ever I do to the group SOP it only seems to read groups of points , whenever I have used the edit TAB in the group SOP to try and convert points to primative group , I get the RED play arrow.
regards R
Houdini Lounge » a good editor
- circusmonkey
- 2624 posts
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Houdini Lounge » extrude SOPs
- circusmonkey
- 2624 posts
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Thanks again Edward ! and Alex, I hope you can suffer my questions however simple they may seem as I am sure to have more very soon !
R
R
Houdini Lounge » extrude SOPs
- circusmonkey
- 2624 posts
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I note there are several options for extruding SOP poly extrude / and SOP extrude. If I create a circle I can use either SOP , but only with poly extrude SOP can I add divisions to the extrusion. What if I am using a nurbs circle and wish to extrude that how do I add divisions to my nurbs extrusion ?
R
R
Houdini Lounge » Limited tutorials
- circusmonkey
- 2624 posts
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thanks for the comments guys , Sidfx should not be relying on 3rd party vendors to produce there learning material that is business suicide. If you want more experienced people to learn / use promote houdini you have to make it easy to pick up fast .I had a job a while ago , seeds blowing off a flower dandylion head.Using houdini would of been great , but just looking at the difficulties I have had this week , with only this place to ask questions , and docs with large holes in. I would not of been able to complete the job in time.
I know the gnomon DVDs are a great start , theres another coming out soon,but please sidefx employ somebody to produce better content for your help , because the more into you put ino help Tus the more people will pick it up !
R
I know the gnomon DVDs are a great start , theres another coming out soon,but please sidefx employ somebody to produce better content for your help , because the more into you put ino help Tus the more people will pick it up !
R
Houdini Lounge » Limited tutorials
- circusmonkey
- 2624 posts
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IF sidefx want more people to take up Houdini how come they dont produce more tutorials / better help with the application.I am coming from xsi /maya and the biggest thing stopping me ramping up quickly is the lack of information.I am used to normally relying on the sdk help / help but its so fustrating knowing what I want to do but not knowing where to look, just look at the xsi HTML help or the xsi SDK , or Maya Mel reference.
R
R
Houdini Lounge » expression help
- circusmonkey
- 2624 posts
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Houdini Lounge » expression help
- circusmonkey
- 2624 posts
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I have created a circle and used a poly extrude sop to create a cylinder which I can then add subdivisions to.
I am looking at creating an expression that increases the amount of divisions the more I translate the extrude in Y
So far I know that I want a minium of 3 subdivisons per unit of lengh. So this is where I start to come unstuck, I have worked out that ( $BBY ) is the the height of my object at any time so if that should maybe measured in 0 to 1
(1-$BBY) from here I am not sure what or how my expression evaluates that it needs 3 subdivisions per unit of extrusion.
I was thinking it would be something like L = D * 3 with L= Lengh D= Divisions
Any help would be gratfully recieved
Rob
I am looking at creating an expression that increases the amount of divisions the more I translate the extrude in Y
So far I know that I want a minium of 3 subdivisons per unit of lengh. So this is where I start to come unstuck, I have worked out that ( $BBY ) is the the height of my object at any time so if that should maybe measured in 0 to 1
(1-$BBY) from here I am not sure what or how my expression evaluates that it needs 3 subdivisions per unit of extrusion.
I was thinking it would be something like L = D * 3 with L= Lengh D= Divisions
Any help would be gratfully recieved
Rob
Houdini Lounge » Moving the objects centre point/ transform axis
- circusmonkey
- 2624 posts
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I create a line using line SOP / its centre point is at 0,0,0 , I create a tube SOP its centre point is 0,5,0 if it is 10units in height. How do I move the axis/centre point of an object , for instance to one end of a tube.
In xsi I would select a bunch of verts and use “centre to selection”.
R
In xsi I would select a bunch of verts and use “centre to selection”.
R
Houdini Lounge » Hi all
- circusmonkey
- 2624 posts
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Just thought I would introduce myself and say hello , I hope to be using houdini at some point in the future , although being more artist than technical I shall see how I get on, certainly impressed , so far ..the biggest difficulty is seeing that the same hot key works differently in each pane > and switching between all the modes !!!
One other question , Ive created a curve sop , what sop can I use to add / remove points and alter my basic curve ?
R
One other question , Ive created a curve sop , what sop can I use to add / remove points and alter my basic curve ?
R
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