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This tool creates an object which takes its transform from the world-space position of a UV point on a polygonal surface. You can then parent another object to the Sticky object to make the object follow the surface.
This is similar to the Rivet tool; however, this tool is more precise since you can attach the sticky anywhere on the surface and you can animate the position as well as the object. For example, you could animate a monkey riding on an elephant’s back while sliding across the surface trying to balance.
The Sticky Object gets its transform from the surface of a polygonal mesh. The mesh must also have texture coordinates that are used to determine the parameterization of the polygons.
Sticky Objects may be parented to other sticky objects. In this case they will parent their 2d UV transformation (both the UV offset and the rotation). If one parents sticky objects, the Fetch World Transform should be turned on.
The Sticky Geometry path determines the object to stick to. To stick objects to sticky geometry, you must parent the geometry you want stuck to the Sticky node.
For example to stick a sphere to a grid, make sure the grid has uv texture attributes, create a Sticky Object, set the Sticky Geometry to the grid, and parent the sphere to the Sticky Object.
The SOP to stick the geometry to.
The attribute name of the texture to use for the polygonal parameterization.
The UV coordinates to evaluate the mesh at.
The angle to rotate the local coordinate frame about the surface normal. It will only take effect when Orient to Surface is on. However, any other sticky objects parented to this one will inherit this rotation.
Orient To Surface
Whether the local orientation of the point should be used. The surface normal is used as the Z axis and the texture’s U axis is used as the Y axis.
Fetch World Transform
If this is set, the transform of the Sticky Geometry will be used. If not set, the parent transform of this node will be used.
Wrap in U/V
When not set, u and v values outside the range will be ignored. When it is set, they will be wrapped until they lie within the range.
This is the range of texture space to work within. Geometry whose texture coordinates lie outside this range will be ignored.
Assume UV Coordinates Unchanging
The sticky object builds a cache of the target surface’s texture coordinates. When this is set, the cache is kept even if the target’s geometry changes.
Clear UV Caches
The Sticky Object is conservative about rebuilding the UV information. This will force it to update the UV texture lookups.
Whether or not this object is displayed in the viewport and rendered. Turn on the checkbox to have Houdini use this parameter, then set the value to 0 to hide the object in the viewport and not render it, or 1 to show and render the object. If the checkbox is off, Houdini ignores the value.
Set Wireframe Color
Use the specified wireframe color
The display color of the object
Viewport Selecting Enabled
Object is capable of being picked in the viewport.
Script to run when the object is picked in the viewport. See select scripts .
Cache Object Transform
Caches object transforms once Houdini calculates them. This is especially useful for objects whose world space position is expensive to calculate (such as Sticky objects), and objects at the end of long parenting chains (such as Bones). This option is turned on by default for Sticky and Bone objects.
See the OBJ Caching section of the Houdini Preferences window for how to control the size of the object transform cache.
Uniform scaling about the xyz axes.
Whether to display only the icon, only the axis, or both.
Displays only the icon geometry.
Displays only the axis.
Icon and Axis
Displays both the icon and axis.
Switches between the type of geometry to display.
Displays null geometry (i.e. cross).
Displays circle primitives.
Displays box primitive.
Displays plane primitives.
Null and Circles
Displays null and circle primitives.
Null and Box
Displays null and box primitives.
Null and Planes
Displays null and plane primitives.
If an input source is specified, this option will display the geometry of the input.
Used in conjunction with circle or plane primitives. Determines which circles or planes to display.
Displays circle or plane primitives on the YZ, ZX and XY planes.
Displays a circle or plane primitive on the YZ plane.
Displays a circle or plane primitive on the ZX plane.
Displays a circle or plane primitive on the XY plane.
YZ, ZX planes
Displays circle or plane primitives on the YZ and ZX planes.
YZ, XY planes
Displays circle or plane primitives on the YZ and XY planes.
ZX, XY planes
Displays circle or plane primitives on the ZX and XY planes.
Determines whether to display the primitives as shaded objects or as wireframe objects.
Displays primitives in wireframe mode.
Displays primitives in shaded mode.
In this example, a donut is stuck to an animated sticky object on the surface of a grid.
The following examples include this node.