Geometry COMP

From TouchDesigner 088 Wiki

Summary

The Geometry Component is a 3D surface that you see and render in TouchDesigner with a Render TOP. Lights, Cameras and other Components affect the scene, but are not visible surfaces. Each Geometry Component contains a network with SOPs, where SOPs are the operators that define its 3D shape. The 3D surfaces can be polygons, particles, sprites, meshes, NURBS (with trim curves), Bezier patches or metaballs. They can be rendered as solid-shaded surfaces or as wireframes.

In the Geometry COMP's network, the [SOP]]s (Surface Operators) whose Render flag is On are rendered by a Render TOP. (SOPs whose Display flag is on are seen in the camera component viewers.)

More than one SOP can be turned on for rendering in a Geometry component.

Some SOPs, like the Texture SOP determine how texture images wrap and fit on the surface.

Every Geometry component needs a material operator to apply to the surface. This is assigned in the Material parameter of the Geometry component, or with a Material SOP.

To get to the Geometry Component's network, use the roller wheel to zoom into it, or select Enter Component from the component's pop-up menu, or hit Enter or 'd' after selecting a Geometry Component.

See Render Flag and Display Flag.

PythonIcon.png geometryCOMP_Class

Geometry Component.jpg

Parameters - Xform Page

The Xform parameter page controls the object component's transform in world space.

Transform Order xord - The menu attached to this parameter allows you to specify the order in which the changes to your Component will take place. Changing the Transform order will change where things go much the same way as going a block and turning east gets you to a different place than turning east and then going a block. In matrix math terms, if we use the 'multiply vector on the right' (column vector) convention, a transform order of Scale, Rotate, Translate would be written as translate * rotate * scale * vector.

Rotate Order rord - The rotational matrix presented when you click on this option allows you to set the transform order for the Component's rotations. As with transform order (above), changing the order in which the Component's rotations take place will alter the Component's final position.

Translate / Rotation / Scale t[xyz] r[xyz] s[xyz] - The three fields allow you to specify the amount of movement along any of the three axes; the amount, in degrees, of rotation around any of the three axes; and a non-uniform scaling along the three axes. As an alternative to entering the values directly into these fields, you can modify the values by manipulating the Component in the Viewport with the Select & Transform state.

Pivot p[xyz] - The Pivot point edit fields allow you to define the point about which a Component scales and rotates. Altering the pivot point of a Component produces different results depending on the transformation performed on the Component.

For example, during a scaling operation, if the pivot point of an Component is located at -1, -1, 0 and you wanted to scale the Component by 0.5 (reduce its size by 50%), the Component would scale toward the pivot point and appear to slide down and to the left.

Objects17.gif

In the example above, rotations performed on an Component with different pivot points produce very different results.

Uniform Scale scale - This field allows you to change the size of an Component uniformly along the three axes.

Note: Scaling a camera's channels is not generally recommended. However, should you decide to do so, the rendered output will match the Viewport as closely as possible when scales are involved.

Constrain To constrain - Allows the location of the object to be constrained to any other object whose path is specified in this parameter.

Look At lookat - Allows you to orient your Component by naming the Component you would like it to Look At, or point to. Once you have designated this Component to look at, it will continue to face that Component, even if you move it. This is useful if, for instance, you want a camera to follow another Component's movements. The Look At parameter points the Component in question at the other Component's origin.

Tip: To designate a center of interest for the camera that doesn't appear in your scene, create a Null Component and disable its display flag. Then Parent the Camera to the newly created Null Component, and tell the camera to look at this Component using the Look At parameter. You can direct the attention of the camera by moving the Null Component with the Select state. If you want to see both the camera and the Null Component, enable the Null Component's display flag, and use the Select state in an additional Viewport by clicking one of the icons in the top-right corner of the TouchDesigner window.

Look At Up Vector lookup - When specifying a Look At, it is possible to specify an up vector for the lookat. Without using an up vector, it is possible to get poor animation when the lookat Component passes through the Y axis of the target Component.

  • Don't Use Up Vector - Use this option if the look at Component does not pass through the Y axis of the target Component.
  • Use Up Vector - This precisely defines the rotates on the Component doing the looking. The Up Vector specified should not be parallel to the look at direction. See Up Vector below.
  • Use Quaternions - Quaternions are a mathematical representation of a 3D rotation. This method finds the most efficient means of moving from one point to another on a sphere.

Path SOP pathsop - Names the SOP that functions as the path you want this Component to move along. For instance, you can name an SOP that provides a spline path for the camera to follow.

Production Tip: For Smooth Motion Along a Path - Having a Component follow an animation path is simple. However, when using a NURBS curve as your path, you might notice that the Component speeds up and slows down unexpectedly as it travels along the path. This is usually because the CVs are spaced unevenly. In such a case, use the Resample SOP to redistribute the CVs so that they are evenly spaced along the curve. A caution however - using a Resample SOP can be slow if you have an animating path curve.

An alternative method is to append a Basis SOP to the path curve and change it to a Uniform Curve. This way, your Component will move uniformly down the curve, and there is no need for the Resample SOP and the unnecessary points it generates.

Roll roll - Using the angle control you can specify a Component's rotation as it animates along the path.

Position pos - This parameter lets you specify the Position of the Component along the path. The values you can enter for this parameter range from 0 to 1, where 0 equals the starting point and 1 equals the end point of the path. The value slider allows for values as high as 10 for multiple "passes" along the path.

Orient Along Path pathorient - If this option is selected, the Component will be oriented along the path. The positive Z axis of the Component will be pointing down the path.

Up Vector up - When orienting a Component, the Up Vector is used to determine where the positive Y axis points.

Auto-Bank Factor bank - The Auto-Bank Factor rolls the Component based on the curvature of the path at its current position. To turn off auto-banking, set the bank scale to 0.


Parameters - Pre-Xform Page

The Pre-Xform parameter page applies a transform to the object component before the Xform page's parameters are applied. That is, it is the same as connecting a Null COMP as a parent of this node, and putting same transform parameters in there as you would in the Pre-Xform page. In terms of matrix math, if we use the 'multiply vector on the right' (column vector) convention, the equation would be preXForm * xform * vector.

Xform Matrix/CHOP/DAT xformmatrixop - This parameter can be used to transform using a 4x4 matrix directly. If a CHOP is used, the 16 elements of the matrix are taken from the first 16 channels of the CHOP. It only uses the first sample of each channel. The matrix data is laid out in such as way that the 13th, 14th and 15th channels contain the translation. This can be thought of as either column or row-major conventions, reading the channels column by column or row by row.

If a DAT is used it should be a 4x4 table with the desired matrix values in each cell. The translation should be in the last column, which means it is using the convention of multiplying vectors/points on the right of the matrix (like GLSL does). If you are converting from a Table DAT using a DAT to CHOP, you'll want to use a Transpose DAT to get the channels in the correct order. It applied to the Xform Matrix in the Pre-Xform page of all Object CHOPs and the Projection Matrix in the View page of Lights and Cameras.

A tdu.Matrix can also be directly specified. Example of using a tdu.Matrix:

m = tdu.Matrix()
m.translate(5, 0, 0)
m.rotate(0, 45, 0)
someNode.store(‘xformMat’, m)

and in the node parameter you would put:

me.fetch(‘xformMat’)


Parameters - Instance Page

The Instance parameter page provides the ability to create hardware instances of geometry. This is only supported on Geforce 8000 series and better graphics cards. Each instance has an instance ID which can be passed into a MAT shader via a uniform value. The instance ID can be retrieved by the Render Pick CHOP. Any code in a vertex shader can customize the instance based on the instance ID. Instances can also be transformed using CHOP channels.

Instancing instancing - Turns on instancing for the Geometry Component.

Instance Count instancemode - Two modes to determine how many instances will be created.

  • Manually - Use the Num Instances parameter below to set the number of instances.
  • CHOP Length/DAT Num Rows - The number of CHOP samples/DAT rows in the Instance CHOP/DAT determines the number of instances.

Num Instances numinstances - When using the Manual mode for Instance Count, this parameter set the number of instances.

Instance CHOP/DAT instanceop - Specify a path to a CHOP or DAT used to transform the instances. Number of samples/rows in this CHOP or DAT determines the number of instances when using the CHOP Length/DAT Num Rows mode for Instance Count.

First Row is instancefirstrow - What to do with the first row of a table DAT when using DAT rows for Instance Count.

Transform Order instxord - The menu attached to this parameter allows you to specify the order in which the changes to your Component will take place. Changing the Transform order will change where things go much the same way as going a block and turning east gets you to a different place than turning east and then going a block.

Rotate Order instrord - The rotational matrix presented when you click on this option allows you to set the transform order for the Component's rotations. As with transform order (above), changing the order in which the Component's rotations take place will alter the Component's final position.

T[XYZ] instancet[xyz] - Select the channel/column (by name) to use from the Instance CHOP/DAT to translate instances.

R[XYZ] instancer[xyz] - Select the channel/column (by name) to use from the Instance CHOP/DAT to rotate instances.

S[XYZ] instances[xyz] - Select the channel/column (by name) to use from the Instance CHOP/DAT to scale instances.

Rotate to Vector[XYZ] instances[xyz] - Select the channel/column (by name) to use from the Instance CHOP/DAT to rotate to vector instances.

Rotate Up[XYZ] instances[xyz] - Select the channel/column (by name) to use from the Instance CHOP/DAT to rotate up instances.

Instance Order instanceorder - Sets how transforms are applied to the instances.

  • Instance, then World Transform - Use the individual instance transforms first, then apply the world transform (i.e. Xform and Pre-Xform parameter pages).
  • World Transform, then Instance - Use the world transform first, then apply the individual instance transforms.

Parameters - Instance 2 Page

Texture Mode instancetexmode - Set how the texture coordinates are applied to the instances.

  • Replace - Replaces texture coordinates.
  • Offset - Offsets texture coordinates.

U V W instance[uvw] - Select the channel/column (by name) to use from the Instance CHOP/DAT to apply texture coordinates to the instances. This interacts with the first texture layer uv[0] attributes coming from the SOP.

Color Mode instancecolormode - Controls how the instance color values interact with the SOPs 'Cd' (diffuse color) attribute. If the SOP doesn't have a 'Cd' attribute, then it will behave as if its 'Cd' is (1, 1, 1, 1).

R G B A instance[rgba] - Select the channel/column (by name) to use from the Instance CHOP/DAT to apply to the diffuse color of the instances. These parameters will be combined/replaced with the SOPs 'Cd' attribute, as chosen by the Color Mode parameter.

Instance Textures instancetexs - Specify a TOP containing the textures to use with the instances. Only supported on Kepler (Geforce 600+, Quadro K series) cards.

Texture Index instancetexindex - Select a channel/column (by name) to use from the Instance CHOP/DAT to select which texture to use for the instances. Only supported on Kepler (Geforce 600+, Quadro K series) cards.

Parameters - Render Page

The Display parameter page controls the component's material and rendering settings.

Material material - Selects a MAT to apply to the geometry inside.

Render render - Whether the Component's geometry is visible in the Render TOP. This parameter works in conjunction (logical AND) with the Component's Render Flag.

Draw Priority drawpriority - Determines the order in which the Components are drawn. Smaller values get drawn after (on top of) larger values.

Wireframe Color wcolor - Use the R, G, and B fields to set the Component's color when displayed in wireframe shading mode.


Light Mask lightmask - Defines which lights will illuminate the geometry in the Component. Accept Pattern Matching as described in the Scripting Guide.

Parameters - Common Page

The Common parameter page sets the component's node viewer, clone relationships, Parent Shortcut, and Global OP Shortcut.

Parent Shortcut parentshortcut - Specifies a name you can use anywhere inside the component as the path to that component. See Parent Shortcut.

Global OP Shortcut opshortcut - Specifies a name you can use anywhere at all as the path to that component. See Global OP Shortcut.

Node View - Determines what is displayed in the node viewer, also known as the Node Viewer. Some options will not be available depending on the Component type (Object Component, Panel Component, Misc.)

  • Geometry Viewer - Shows a 3D geometry viewer displaying the geometry inside the component. This option is only available for Object components.
  • Control Panel - Displays the Control Panel, only available for Panel Components.
  • Operator Viewer - Displays the node viewer from any operator specified in the Operator Viewer parameter below.

Operator Viewer opviewer - Select which operator's node viewer to use when the Node View parameter is set to Operator Viewer.

Enable Cloning enablecloning - Control if the OP should be actively cloned.

Clone Master clone - Path to a component used as the Master Clone. If the component specified as Master exists, then this component becomes a clone.

Load On Demand loadondemand - Loads the component into memory only when required. Good to use for components that are not always used in the project.

External .tox externaltox - Path to a .tox file on disk which will source the component's content upon start of a .toe. This allows for components to contain networks that can be updated independently of the .toe file. Paths used to locate .tox files should not contain expressions or root variables. Built-in and Environment variables (like $MYDOCUMENTS, $DESKTOP and $HOME) are accepted. If the .tox file can not be found, whatever the .toe file was saved with will be loaded.

Reload .tox on Start reloadtoxonstart - When on (default), the external .tox file will be loaded when the .toe starts and the contents of the COMP will match that of the external .tox. This can be turned off to avoid loading from the referenced external .tox on startup if desired (the contents of the COMP are instead loaded from the .toe file). Useful if you wish to have a COMP reference an external .tox but not always load from it unless you specifically push the Re-Init Network parameter button.

Save Backup of External savebackup - When this checkbox is enabled, a backup copy of the component specified by the External .tox parameter is saved in the .toe file. This backup copy will be used if the External .tox can not be found. This may happen if the .tox was renamed, deleted, or the .toe file is running on another computer that is missing component media.

Sub-Component to Load subcompname - When loading from an External .tox file, this option allows you to reach into the .tox and pull out a COMP and make that the top-level COMP, ignoring everything else in the file (except for the contents of that COMP). For example if a .tox file named project1.tox contains project1/geo1, putting geo1 as the Sub-Component to Load, will result in geo1 being loaded in place of the current COMP. If this parameter is blank, it just loads the .tox file normally using the top level COMP in the file.

Re-Init Network reinitnet - This button will re-load from the external .tox file (if present), followed by re-initializing itself from its master, if it's a clone.


See Also