Forums Search
Found 127 posts.

Search results Show results as topic list.

H20 Tech Art Challenge » Best Houdini Utility Entries

User Avatar
ObeidaZakzak
127 posts
Offline
 
Attribute Combine Vector SOP


This is similar to Attribute Combine SOP, but it only combines vectors, and it has specific operations, such as Cross product, Projection, and Rotation.

In a typical Houdini workflow, you will be manipulating attributes, adjusting and combining them. There's so many helpful nodes to make this easy. And the Attribute Combine Vector SOP is an addition to the user-friendly nodes that help quickly combine vector attributes, with spherical interpolation.

It can be used in many workflows, whenever it involves vector attributes. Hope you find helpful in your setups !

Check out the HDA's help card for some explanation of combine operations, and the attached hip file for examples shown in the video.

P.S : in this gold release, I added a second input to select attributes from a second geometry.






See full post 

Technical Discussion » How to accces prim intrinsic "bounds" values? [{SOLVED}]

User Avatar
ObeidaZakzak
127 posts
Offline
 
Hello,

Acessing intrinsic attributes requires using some functions, such as primintrinsic() or detailintrinsic() in VEX.

In your case, accessing bounds at index 3 looks like this in an attribute wrangle :

float bounds[] = primintrinsic(0, "bounds", @primnum);
f@bound3 = bounds[3];

Edited by ObeidaZakzak - Jan. 13, 2024 07:28:14
See full post 

Technical Discussion » Problem with Feathers, how can i export them to c4d?

User Avatar
ObeidaZakzak
127 posts
Offline
 
Hello,

You need to uncondense them before exporting to another software, using the Feather Uncondense SOP. This will convert feathers to curves (shaft+barbs) with attributes.
Edited by ObeidaZakzak - Jan. 13, 2024 05:48:50
See full post 

Technical Discussion » Is there a quick way to embed HDA(s)?

User Avatar
ObeidaZakzak
127 posts
Offline
 
Embedding an asset in a HIP file [www.sidefx.com]

You can save a copy of your HDA in the HIP (RMB > Digital Asset > Save Copy As > Location:Embedded), this allows users to create new instances of the HDA in this HIP if needed. Make sure to remove the '_copy' suffix to match operator name and update all instances of the HDA with the embedded one.
Edited by ObeidaZakzak - Jan. 7, 2024 04:29:33
See full post 

Technical Discussion » [H20] Language selection menu for expressions

User Avatar
ObeidaZakzak
127 posts
Offline
 
Don't know the reason why this menu was removed (couldn't find any info on the changelog), but there's a HOM function to do so :
hou.OpNode.setExpressionLanguage() [www.sidefx.com]

My workaround for this is to add script items to the parm gear menu Customize menus [www.sidefx.com]
See full post 

H20 Tech Art Challenge » WIP - Attribute Combine Vector SOP - [Houdini Utility]

User Avatar
ObeidaZakzak
127 posts
Offline
 
v0.6

And here's a hip to demonstrate vector operations by visualizing three vectors (operands and result).
See full post 

H20 Tech Art Challenge » WIP - Attribute Combine Vector SOP - [Houdini Utility]

User Avatar
ObeidaZakzak
127 posts
Offline
 
v0.5 : available to dwonload and test
  • Fixed a couple of bugs and performance issues, and reworked the structure of the VEX script so it's easier to maintain
  • Added a menu to select an adjustment operation on the combine vector (normalize or scale)
  • Added group parm so the combine operations apply only on selected group

Attached a hip file demonstrating how to bend and twist curves using this tool.
See full post 

Technical Discussion » Feather Orientation

User Avatar
ObeidaZakzak
127 posts
Offline
 
Hello,

Based on your screenshot, you use Guide Tangent Space node after the Guide Groom node.

It can set an orient attribute procedurally, so if you are outputing the barborient attribute with guide tangent space node, it will override your bursh work in guide groom node.

EDIT : So when you want to create barborient attribute procedurally before starting brush work, you can add guide tangent space node before guide groom node, not after it. Here's an example hip file.
Edited by ObeidaZakzak - Dec. 21, 2023 15:29:20
See full post 

Technical Discussion » Faster launch times?

User Avatar
ObeidaZakzak
127 posts
Offline
 
wlvl_gv
2. Is there a way to print out each step houdini is executing during lauch?

When loading your plugins from a server, you can use Wireshark to monitor the file requests sent by Houdini.

When loading plugins on the same machine, you can use ProcessMonitor (I know this one for Windows at least).

I had (still having ^^) a similar issue with launch time for Houdini in general from a NAS/server containing plugins, and got help from IT/SysAdmins to analyze data provided with these tools, and noticed that Houdini requests many files (like about 80k file requests) that do not exist.
See full post 

Technical Discussion » Labs Maps Baker does not output files via TOPS

User Avatar
ObeidaZakzak
127 posts
Offline
 
Hello,

You need to tell ROP Fetch TOP the name of the parameter containing the output filename in the Maps Baker node.

It can recognize it automatically for ROPs built in Houdini, but when you work with HDAs (like the Labs Maps Baker), you have to tell the exact name of this parm (as well as the parm/button that runs the render operation, usally called "execute").

In your scene, you need to set "Output Parm Name" to "sOutputFile" in the ropfetch node.
See full post 

Houdini Lounge » How to make a string parameter show as multiple lines

User Avatar
ObeidaZakzak
127 posts
Offline
 
You can open a text editor to edit the expression. Right click on the parm, in the Expression tab, select Edit Expression/string (or hit Alt+E)
See full post 

Technical Discussion » Houdini 20 new texture mask paint node limitations?

User Avatar
ObeidaZakzak
127 posts
Offline
 
Hello @FoamFX

Glad to help ^^

FoamFX
Btw I think (based on your latest setup)there's a simple workaround to be able to view modification to the texture, which is using UVquickshade node reading from cops.

Indeed, quickshade node gives feedback on texture modifications. Thanks for pointing this out !
See full post 

Technical Discussion » Houdini 20 new texture mask paint node limitations?

User Avatar
ObeidaZakzak
127 posts
Offline
 
Indeed, you will not be able to visualize the mask data from the geometry, as the texture data lives inside a 2D volume, not inside the geo.

You can add another Texture Mask Paint after modifications on the texture volume and enter the node state to visualize what happend.

However, I was playing around to find another way to visualize this volume, I found a way by importing texture volume into COPs, then coloring it with a ramp and sending it to a principaled shader, and assigning this shader to the geometry.

For some reason, any modification to the texture volume doesn't show on the shader interactively, to see modifications you should undisplay then display the texture_mask_shade node, or trigger a change in the color ramp.

Here's a hip file to see how to do it.
See full post 

Technical Discussion » Houdini 20 new texture mask paint node limitations?

User Avatar
ObeidaZakzak
127 posts
Offline
 
Hello @mleff,

You need to sample the 3D position of the geo having the uv attrib.

In the texture primitive/volume, the voxel position is the uv position of the input geo.

So in the uvsample function, you will need to sample the P attrib of the geo in it's uv space, using the position of the voxel (also called P in volume wrangle).

Here's a hip file with an example.
See full post 

Technical Discussion » Houdini 20 new texture mask paint node limitations?

User Avatar
ObeidaZakzak
127 posts
Offline
 
Regarding the grooming part, existing grooming nodes have a "Volume" or "Skin VDB" input, where you can plug in the texture volume/primitive, and use it as an override option on parms that support this feature. You don't have to convert this Texture Volume into an attribute in this case, as these nodes support Texture Primitives already.

You can also find some examples on how to convert an attribute into a texture volume, and a texture volume into an attribute (Attribute from Map SOP is the easiest way, but there's an example with VEX).
Edited by ObeidaZakzak - Dec. 7, 2023 13:24:25
See full post 

Houdini Lounge » HDA operator's default shape and color in Network View

User Avatar
ObeidaZakzak
127 posts
Offline
 
A good way to do this is by setting the shape and color in the HDA's OnCreated script.

kwargs["node"].setColor(hou.Color((1, 0.725, 0)))
kwargs["node"].setUserData('nodeshape', 'circle')

The list of available shapes can be accessed with hou.NetworkEditor.nodeShapes method.
See full post 

Technical Discussion » How to create a multi-select menu with check to HDA?

User Avatar
ObeidaZakzak
127 posts
Offline
 
Checkmarks seem to be available on menus built with HDK only (I only see them on compiled nodes), I couldn't find a way to do this when building an HDA, in many cases the trick is to promote a parameter that already has that menu with checkmark (group parameter in most cases).

As said by @jsmack, a checkmark string can help here, I tried this and it works fine :

a = ("a", "A")
b = ("b", "B")

pairs = [a, b]

menu = []
for p in pairs:
    menu.append(p[0])
    if p[0] in hou.evalParm("my_list").split(" "):
        menu.append(p[1] + " ✓")
    else:
        menu.append(p[1])

return menu
See full post 

Technical Discussion » How to apply SOP non-uniformly using point attribute?

User Avatar
ObeidaZakzak
127 posts
Offline
 
Hi,

The Sweep SOP can use the @pscale attribute to drive the radius along the curve. So if you set @pscale instead of @radius in the Attribute Randomize, you should get the result you are looking for, without having to write any expression in sweep node.

EDIT : it's just same thing as said by @animatrix_ we were writing at same time ^^
Edited by ObeidaZakzak - Dec. 1, 2023 13:34:14
See full post 

H20 Tech Art Challenge » WIP - Attribute Combine Vector SOP - [Houdini Utility]

User Avatar
ObeidaZakzak
127 posts
Offline
 
v0.2

  • All attribute classes are supported (point/primitive/vertex/detail)
  • Multiple combines can be done
  • Choice between a vector attribute or a constant vector parm to be combined
  • Added new operations : Copy, Add, Subtract
  • Added post-processing : normalize, and overal scale

Still TBD :
  • Adjust/process combined attrib before applying operation
  • Apply this node on a given group only

Creation of xform and/or orient attributes may come in another HDA, rather than being part of post-processing of this HDA.
Edited by ObeidaZakzak - Nov. 26, 2023 17:17:28
See full post 

Houdini Indie and Apprentice » H20 textureMask Udim

User Avatar
ObeidaZakzak
127 posts
Offline
 
You will need to provide a udim tile number attribute to make it work. This can be done with the Labs Udim Tile Number node [www.sidefx.com]
See full post 
  • Quick Links