http://www.sidefx.com/images/stories/blogs/houdini9_blog/h9_quick_ref_card.pdf [sidefx.com]
It's for H9 but guess most of the stuff still works (to some extend).
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Houdini Indie and Apprentice » is there a way to change Rotate Axis
- Pagefan
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Houdini Indie and Apprentice » is there a way to change Rotate Axis
- Pagefan
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Houdini Indie and Apprentice » Controlling with attractors (modeling challenge)
- Pagefan
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Anna,
here is the rest of the file. You turned it into a nice python thread. Think i'll try to pythonify my setup this weekend.
here is the rest of the file. You turned it into a nice python thread. Think i'll try to pythonify my setup this weekend.
Houdini Indie and Apprentice » Controlling with attractors (modeling challenge)
- Pagefan
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Also, when looking at Pagefan's code, I am not sure I understand correctly:
attribcreate_pointdistance creates one attribute and puts three floats into it referring to distances to each of the attractors, right?
Yes you are right about that. In the color_volumepoints I use them to make the RGB color. The attribcreate_pointdistance creates the PTDIST attribute. I use that attribute in the color_volumepoints like this: $PTDIST1 for the first value of the 3-float attribute and $PTDIST2 for the 2nd etc…
The truncated line probably means either that it is a secondary input to a node. I guess you deleted your null node and now it is wired into the 2nd input of a copy or point node.
Houdini Indie and Apprentice » Controlling with attractors (modeling challenge)
- Pagefan
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Anna,
the color_points work because the attractors are sphere primitives, they only have one piont, one primitive and one vertex. So in the color_points I just selected sphere 0, 1 and 2 (hard coded in the group).
I first started out with a single point for attractor (with the same setup) but thought a nice sphere might give some more feedback of what is going on in case you want to animate the attractors.
And yes, Graham is right about the position of the point sops, they should have been before the merge node!
the color_points work because the attractors are sphere primitives, they only have one piont, one primitive and one vertex. So in the color_points I just selected sphere 0, 1 and 2 (hard coded in the group).
I first started out with a single point for attractor (with the same setup) but thought a nice sphere might give some more feedback of what is going on in case you want to animate the attractors.
And yes, Graham is right about the position of the point sops, they should have been before the merge node!
Houdini Indie and Apprentice » Controlling with attractors (modeling challenge)
- Pagefan
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Houdini Indie and Apprentice » Controlling with attractors (modeling challenge)
- Pagefan
- 519 posts
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Houdini Indie and Apprentice » Controlling with attractors (modeling challenge)
- Pagefan
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In the lookat node there is an expression to create the normals. It is also a point SOP like the color node. Since there is nothing but points in the scene atm it is very easy to create a vector (the normal in this case) by subtracting the two point positions:
point(“../FOCUS, 0, ”P", 0)-$TX
which means, get the x-value of point number 0 on the FOCUS node and subtract the x-value of the current point (the points part of the lookat sop).
In the color_point node pretty much the same thing happens except for the color attributes.
I'll post the first part of the network later tonight. In the meantime try to figure out how the attribpromote sop works.
*edit* Rob…you changed Australia for NY?
point(“../FOCUS, 0, ”P", 0)-$TX
which means, get the x-value of point number 0 on the FOCUS node and subtract the x-value of the current point (the points part of the lookat sop).
In the color_point node pretty much the same thing happens except for the color attributes.
I'll post the first part of the network later tonight. In the meantime try to figure out how the attribpromote sop works.
*edit* Rob…you changed Australia for NY?
Houdini Indie and Apprentice » Controlling with attractors (modeling challenge)
- Pagefan
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The color_point node is a renamed point sop. You can rename your nodes so that you, or somebody else, can figure out, to a certain extend, what they do. So this point sop adds the color attribute.
The null_basevolume is just a left over, it is not neccesarry in the current setup. But the null node is very handy as a “placeholder”. When you have scripts you can reference a null node and change the network above without having to worry that your script might break. I also use them because i am terribly lazy: it is easier to type PCOL in an expression than color_point or whatever name sops normally have.
When you are at the attribpromote SOP and you still haven't figured out what to do, post your hip file and i'll take a look.
The null_basevolume is just a left over, it is not neccesarry in the current setup. But the null node is very handy as a “placeholder”. When you have scripts you can reference a null node and change the network above without having to worry that your script might break. I also use them because i am terribly lazy: it is easier to type PCOL in an expression than color_point or whatever name sops normally have.
When you are at the attribpromote SOP and you still haven't figured out what to do, post your hip file and i'll take a look.
Houdini Indie and Apprentice » Controlling with attractors (modeling challenge)
- Pagefan
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Yup i did
If you have trouble with it i can give you some more leads. I think the trickiest part is getting the right values for the switch sop but as i said, the vop scatter tutorials has some great pointers at how you can solve that. This setup also uses that atttributepromote SOP. So to answer your question from the other thread…when you have a detail attribute on your geometry you can uses it with the detail expression:
detail(“../pathtosop”, “attrname”, index)
Cheers,
Hans
If you have trouble with it i can give you some more leads. I think the trickiest part is getting the right values for the switch sop but as i said, the vop scatter tutorials has some great pointers at how you can solve that. This setup also uses that atttributepromote SOP. So to answer your question from the other thread…when you have a detail attribute on your geometry you can uses it with the detail expression:
detail(“../pathtosop”, “attrname”, index)
Cheers,
Hans
Technical Discussion » Find minimum attribute value in vop
- Pagefan
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If you have point or primitive attributes you can find minimum or maximum values (and average values and a lot more) by using an attributepromote SOP. Pipe in the geometry with the attributes, set the new class to (for example) detail and the promotion method to whatever you need.
Houdini Indie and Apprentice » Controlling with attractors (modeling challenge)
- Pagefan
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Hi Anna,
you can try to do something like this:
1
you can try to do something like this:
1
- Use whatever you want to generate a the volume, just a simple box, metaballs or an imported file. Use the pointsfromvolume sop to generate random points inside the geometry.
2I created three primitive spheres to use as attractors (primitive type should be primitive) and colored them.
3Add a series of attributes to calculate the distance. First start of with a 3 float attribute to calculate the distance of each point to each of the attractors(attribcreate_pointdistance). Then use an attributepromote to get the maximum value of each of these distances (promote to a detail attribute). Then you can normalize each of the distances by dividing the distance by the maximum distance and use these fro RGB values (color_volumepoints).
4Add whatever you want
5Use a copy sop with a stamp function to copy your geometry on the points. The trick here is to remap the RGB values to a value of 0-2 which you use in the switch sop with the stamp function. Have a look at Dave Koesters VOP scatter tutorial to get an idea how you can do that. The expression is in the attribute_H sop (the H is from HSV)
6 and 7I used an add sop to create the focus point. After creating the points in the volume you can add a point SOP to create normals; use an expression for the normals (just subtract the position of the point in the volume from the focus point position). The copy sop will orientate the geometry from 4.
Cheers,
Hans
Technical Discussion » config resources file
- Pagefan
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Hey Koen,
my experience with config files is that they reside either in $home or in $hh. If there are two config files with the same name in those dirs, the $hh takes precedence.
An option would be to delete the file in the $hh and give your users either a big font version of the config file or the default config file in their $home dirs.
There is probably (and hopefully) a smarter way to get this done.
Groeten,
Hans
my experience with config files is that they reside either in $home or in $hh. If there are two config files with the same name in those dirs, the $hh takes precedence.
An option would be to delete the file in the $hh and give your users either a big font version of the config file or the default config file in their $home dirs.
There is probably (and hopefully) a smarter way to get this done.
Groeten,
Hans
Technical Discussion » Repeating Animation
- Pagefan
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You can add another file node and set it to read, then read the files in back from disc. Use the expression as filename.
Technical Discussion » learning to script houdini ?
- Pagefan
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hey,
learning python wouldn't hurt since it is used by a lot of other packages. I think sesi intends to get rid of hscript and to use python exclusively. But hscript will be around for some time. It's rather easy to learn and most of the time faster than write than the cmd.cmd().cmd.cmd python stuff
learning python wouldn't hurt since it is used by a lot of other packages. I think sesi intends to get rid of hscript and to use python exclusively. But hscript will be around for some time. It's rather easy to learn and most of the time faster than write than the cmd.cmd().cmd.cmd python stuff
Houdini Indie and Apprentice » repeat texture
- Pagefan
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*warning: very crude explanation*
I suppose it works like in maya, that is scaling your s,t parameters of your surface. In VOPS (think that is slim in maya or the hypershader) there might be a tile vop. When you write your own shaders you prolly want to do something like:
float ss = s / scale;
float tt = t /scale;
Then use ss,tt to scale down your image.
I suppose it works like in maya, that is scaling your s,t parameters of your surface. In VOPS (think that is slim in maya or the hypershader) there might be a tile vop. When you write your own shaders you prolly want to do something like:
float ss = s / scale;
float tt = t /scale;
Then use ss,tt to scale down your image.
Houdini Indie and Apprentice » Reverse Sim
- Pagefan
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Try this:
Blah`$NFRAMES-$SF4`.sim
When you put a global variable in a name it will expand to the value. When you enclose them in ` ` the expression gets evaluated and returns the number you want. (if the ` ` do not work, try “” i tend to confuse the two quite often - trial and error always works…eventually)
Cheers,
Hans
Blah`$NFRAMES-$SF4`.sim
When you put a global variable in a name it will expand to the value. When you enclose them in ` ` the expression gets evaluated and returns the number you want. (if the ` ` do not work, try “” i tend to confuse the two quite often - trial and error always works…eventually)
Cheers,
Hans
Technical Discussion » line segments
- Pagefan
- 519 posts
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Have a look at the ADD sop. It has the option to delete all geometry except the points. Then on the polygon tab you can recreate the curve so that it consists out of 5 primitives. Then you can access the primitive numbers. If you want to keep the original curve you can use an ATTRIBUTETRANSFER sop to copy anything you want back on the orignal curve.
Cheers,
Hans
Cheers,
Hans
Houdini Indie and Apprentice » Rigging Character: render? and what's with the normals here
- Pagefan
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Hey Chris,
the eyes do render but the rest of your Lego man is missing from the file. If it is part of the problem, lock the file sop in the geo node and upload your scene again.
Hans
the eyes do render but the rest of your Lego man is missing from the file. If it is part of the problem, lock the file sop in the geo node and upload your scene again.
Hans
Technical Discussion » Setting material procedurally in the material sop
- Pagefan
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Duh, thought i tried that configuration too, probably made a typo. But it works….
Thanks Tamte
Thanks Tamte
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