I'm presuming …. I could use the expression editor to construct a Hyperbolic using:

$X * $X + $Y - $Z*$Z

or a Sphere using:

$X*$X + $Y*$Y + $Z*$Z - 1

or a Tetrahedron using

max( $Z-2+tan(deg($PI/3))*abs($X) , tan(deg($PI/3))*abs($Y)-$Z-2 )

or a Torus using

(sqrt($X*$X+$Z*$Z)-0.5) * (sqrt($X*$X+$Z*$Z)-0.5) + $Y*$Y - (0.2*0.2)

etc. etc. Sadly, I don't know how to tackle this project.

2nd question how do I save my new Iso surfaces and Primitives to be reused inside Houdini?

Tia!

you can define an implicit function inside the isosurface sop. just put it in the implicit function parm.

not sure what you mean by save? once you create them you can use them as would any other geo

zdimaria
you can define an implicit function inside the isosurface sop. just put it in the implicit function parm.

I'm a new to this!
Where is the Isosurface sop icon/menu item hiding?

TAB menu (over Scene View or Network Editor) > type “isosurface” (inside geometry context)

pusat
TAB menu (over Scene View or Network Editor) > type “isosurface” (inside geometry context)

a picture is worth 1000 words. Sadly the words in the Help menu are failing me. A simple how to would be in order here, are you listening sidefx?

so far I have:

1. hit Tab in 3d view
2. From the Tab menu, hit geometry
3. from geometry flyout menu pick geometry (geo1)
4. Now what ? where do I type ?

I assume, you're quite new to houdini?
You should definetly watch the introduction tutorials from sidefx.
http://www.sidefx.com/index.php?option=com_content&task=blogcategory&id=202&Itemid=361 [sidefx.com]

Dive into the geo container node (select and enter or just double-click).
In the geo (aka sop) context, the isosurface node is available: Hit TAB and start to type isosur… then select the node.

Cheers

bollili
I assume, you're quite new to houdini?
You should definetly watch the introduction tutorials from sidefx.
http://www.sidefx.com/index.php?option=com_content&task=blogcategory&id=202&Itemid=361 [sidefx.com]

Thanks bollili I finally understood…… its all about language
Its a bit strange that Houdini does not simply include those nodes such as Isosurface under another title in the Tab menu.
also I'm currently devouring 35 fundamental videos from 3dbuzz
http://www.3dbuzz.com/training/view/houdini-fundamentals/h9-fundamentals [3dbuzz.com]

On the one hand you're right. On the other hand I think sidefx does a very good job to balance things out. The shelves would be quite cluttered if to much of simple stuff (a geo container plus one node) would be in there.

But, feel free to create a shelve yourself and put in your own tools. That's one of the things where houdini shines. If a kind of building block or even complex tool doesn't exist, just create your own and install it permanently. If you're through the very basics, have a look on the so called ‘digital assets’. One of there core concepts in houdini…

You anticipated my followup question? How do save my Isosurface equations, besides in individual .hip files. There are a number of Isosurfaces listed in the gear icon menu. I would like to append my newly named Isosurfaces to that list.

TIA!

If you want to browse the various operators in a specific network type without holding down the tab key, you can always use the Tool Palette (the gallery) view to do this.

Just drag-n-drop the operators over.

A quick search in the Houdini help for “iso surface” would have returned the Iso Surface SOP along with a bunch of other nodes that can create and modify iso surfaces.

The list under the gear icon is a list of presets.
Et voilá, the same gear icon provides you a option ‘save preset’.

When you click it, you have an option to install the preset to the current file only ($HIP) or to the houdini home folder ($HOME/houdinixx.x) which means you can access this presets also from other houdini sessions.

Is that what you were asking for?

bollili
Is that what you were asking for?

genau… danke schoen!

I was very close, but too timid to use “save preset” because I was not sure what it meant…lol! Fantastic its now part of that menu.

Now suppose I want to share my gyroid Isosurface with other forum users. Where has this file been saved to on my Hdd?
Doing a gyroid*.* search in the Side Effects Software folder yields nothing

jeff
If you want to browse the various operators in a specific network type without holding down the tab key, you can always use the Tool Palette (the gallery) view to do this.

Just drag-n-drop the operators over.

A quick search in the Houdini help for “iso surface” would have returned the Iso Surface SOP along with a bunch of other nodes that can create and modify iso surfaces.

Thanks jeff for chiming in: I will investigate your advice, however I'm a little more concerned about how additional equation Parameters are handled in the Expression editor.
for example: the following isosurface has 2 additional parameters.

ch(“a”) -($X*$X + $Y - $Z*$Z)^2+(cos($X+sin($X)/ch(“b”)) +cos($Y+sin($Y)/ch(“b”)) +cos($Z+sin($Z)/ch(“b”)))

What format will I need to type, that will cause the Expression editor to recognize the Parameters for a and b ?

Tia!

The location of houdini's config is os specific.
I assume, you're on windows…

$HOME is not the application folder in c:\program files
$HOME is set by houdini installer as an environment variable in your windows settings. It points to a houdini config folder in your windows user folder.
http://www.sidefx.com/docs/houdini9.5/basics/config_env [sidefx.com]

For the isosurface sop's presets the path is something like “c:\users\yourUserName\documents\houdinixx.x\presets\sop\iso.idx”

yak
I'm a little more concerned about how additional equation Parameters are handled in the Expression editor.
for example: the following isosurface has 2 additional parameters.

ch(“a”) -($X*$X + $Y - $Z*$Z)^2+(cos($X+sin($X)/ch(“b”)) +cos($Y+sin($Y)/ch(“b”)) +cos($Z+sin($Z)/ch(“b”)))

What format will I need to type, that will cause the Expression editor to recognize the Parameters for a and b ?

Tia!

Try to enclose the ch() expressions in backquotes:

`ch(“a”)`-($X*$X+$Y-$Z*$Z)^2+(cos($X+sin($X)/`ch(“b”)`)
+cos($Y+sin($Y)/`ch(“b”)`)+cos($Z+sin($Z)/`ch(“b”)`))


To make hscript expressions such as ch() evaluate in string fields, you need to encase these expressions in backquotes ``. This will force them to evaluate.

Without the backquotes, the hscript expressions will be evaluated as text only and not as an expression. Only in value parameters are hscript expressions interpreted and evaluated.