3D Nodes

3D Node Modifier

Coordinate Transform 3D

Because of the hierarchical nature of the Fusion 3D node tree, the original position of an object in the 3D scene often fails to indicate the current position of the object. For example, an image plane might initially have a position at 1, 2, 1, but then be scaled, offset, and rotated by other nodes further downstream in the 3D scene, ending up with an absolute location of 10, 20, 5.

This can complicate connecting an object further downstream in the composition directly to the position of an upstream object. The Coordinate Transform modifier can be added to any set of XYZ coordinate controls and calculate the current position of a given object at any point in the scene hierarchy.

To add a Coordinate Transform modifier, simply right-click a number field on any node and select Modify With/CoordTransform Position from the Controls’ contextual menu.

• Target Object
  This control should be connected to the 3D node that produces the original coordinates to be transformed. To connect a node, drag and drop a node from the node tree into the Text Edit control, or right-click the control and select the node from the contextual menu. It is also possible to type the node’s name directly into the control.
• Sub ID
  The Sub ID slider can be used to target an individual sub-element of certain types of geometry, such as an individual character produced by a Text 3D node or a specific copy created by a Duplicate 3D node.
• Scene Input
  This control should be connected to the 3D node that outputs the scene containing the object at the new location. To connect a node, drag and drop a node from the node tree into the Text Edit control, or right-click the control and select an object from the Connect To submenu.

3D Node Common Controls

Nodes that handle 3D geometry share several identical controls in the Inspector. This section describes controls that are common among 3D nodes.

3D Node Common Controls Tab

These controls are often displayed in the lower half of the Controls tab. They appear in nodes that create or contain 3D geometry

• Visibility
  • Visible: If this option is enabled, the object is visible in the viewers and in final renders. When disabled, the object is not visible in the viewers nor is it rendered into the output image by the Renderer 3D node. Also, a non-visible object does not cast shadows.
  • Unseen by Cameras: When the Unseen by Cameras checkbox is enabled, the object is visible in the viewers (unless the Visible checkbox is disabled), except when viewed through a camera. Also, the object is not rendered into the output image by the Renderer 3D node. However, shadows cast by an unseen object are still visible when rendered by the software renderer in the Renderer 3D node, though not by the OpenGL renderer.
  • Cull Front Face/Back Face: Use these options to eliminate rendering and display of certain polygons in the geometry. If Cull Back Face is selected, polygons facing away from the camera are not rendered and do not cast shadows. If Cull Front Face is selected, polygons facing toward the camera are not rendered and do not cast shadows. Enabling both options has the same effect as disabling the Visible checkbox.
  • Suppress Aux Channels for Transparent Pixels: In previous versions of Fusion, transparent pixels were excluded by the software and Open GL render options in the Renderer 3D node. To be more specific, the software renderer excluded pixels with R,G,B,A set to 0, and the GL renderer excluded pixels with A set to 0. This is now optional. The reason you might want to do this is to get aux channels (e.g., Normals, Z, UVs) for the transparent areas. For example, suppose you want to replace the texture on a 3D element that is transparent in certain areas with a texture that is transparent in different areas. It would then be useful to have transparent areas set aux channels (particularly UVs). As another example, suppose you are adding depth of field. You probably do not want the Z-channel to be set on transparent areas, as this gives you a false depth. Also, keep in mind that the exclusion is based on the final pixel color including lighting, if it is on. So, if you have a specular highlight on a clear glass material, this checkbox does not affect it.

• Lighting
  • Affected by Lights: Disabling this checkbox causes lights in the scene to not affect the object. The object does not receive nor cast shadows, and it is shown at the full brightness of its color, texture, or material.
  • Shadow Caster: Disabling this checkbox causes the object not to cast shadows on other objects in the scene.
  • Shadow Receiver: Disabling this checkbox causes the object not to receive shadows cast by other objects in the scene.

• Matte
  Enabling the Is Matte option applies a special texture, causing the object to not only become invisible to the camera, but also making everything that appears directly behind the camera invisible as well. This option overrides all textures.
  • Is Matte: When activated, objects whose pixels fall behind the matte object’s pixels in Z do not get rendered. Two additional options are displayed when the Is Matte checkbox is activated.
  • Opaque Alpha: When the Is Matte checkbox is enabled, the Opaque Alpha checkbox sets the Alpha value of the matte object to 1.
  • Infinite Z: This option sets the value in the Z-channel to infinite. This checkbox is visible only when the Is Matte option is enabled.

• Blend Mode
  A Blend mode specifies which method is used by the renderer when combining this object with the rest of the scene. The blend modes are essentially identical to those listed in the section for the 2D Merge node. For a detailed explanation of each mode, see the section for that node.
  
  The blending modes were originally designed for use with 2D images. Using them in a lit 3D environment can produce undesirable results. For best results, use the Apply modes in unlit 3D scenes using the software option in the Renderer 3D node.
  • OpenGL Blend Mode: Use this menu to select the blending mode that is used when the geometry is processed by the OpenGL renderer in the Renderer 3D node. This is also the mode used when viewing the object in the viewers. Currently the OpenGL renderer supports a limited number of blending modes.
  • Software Blend Mode: Use this menu to select the blending mode that is used when the geometry is processed by the software renderer. Currently, the software renderer supports all the modes described in the Merge node documentation, except for the Dissolve mode.

• Normal/Tangents
  Normals are imaginary lines perpendicular to each point on the surface of an object. They are used to illustrate the exact direction and orientation of every polygon on 3D geometry. Knowing the direction and orientation determines how the object gets shaded. Tangents are lines that exists along the surface’s plane. These lines are tangent to a point on the surface. The tangent lines are used to describe the direction of textures you apply to the surface of 3D geometry.
  • Scale: This slider increases or decreases the length of the vectors for both normals and tangents.
  • Show Normals: Displays blue vectors typically extending outside the surface of the geometry. These normal vectors help indicate how different areas of the surface are illuminated based on the angle at which the light hits it.
  • Show Tangents: Displays green vectors for Y and red vectors of X. The X and Y vectors represent the direction of the image or texture you are applying to the geometry.

• Object ID
  Use this slider to select which ID is used to create a mask from the object of an image. Use the Sample button in the same way as the Color Picker to grab IDs from the image displayed in the viewer. The image or sequence must have been rendered from a 3D software package with those channels included.

3D Node Common Materials Tab

The controls in the Materials tab are used to determine the appearance of the 3D object when lit. Most of these controls directly affect how the object interacts with light using a basic shader. For more advanced control over the objects appearance, you can use tools from the 3D Materials category of the Effects Library. These tools can be used to assemble a more finely detailed and precise shader.

When a shader is constructed using the 3D Material tools and connected to the 3D Object’s material input, the controls in this tab are replaced by a label that indicates that an external material is currently in use.

• Diffuse
  Diffuse describes the base surface characteristics without any additional effects like reflections or specular highlights.
  • Diffuse Color
    The Diffuse Color determines the basic color of an object when the surface of that object is either lit indirectly or lit by an ambient light. If a valid image is provided to the tools diffuse texture input, then the RGB values provided here are also multiplied by the color values of the pixels in the diffuse texture. The Alpha channel of the diffuse material can be used to control the transparency of the surface.
  • Alpha
    This slider sets the material’s Alpha channel value. This affects diffuse and specular colors equally, and affects the Alpha value of the material in the rendered output. If the tools diffuse texture input is used, then the Alpha value provided here is multiplied by the Alpha channel of the pixels in the image.
  • Opacity
    Reducing the material’s Opacity decreases the color and Alpha values of the specular and diffuse colors equally, making the material transparent and allowing hidden objects to be seen through the material.
• Specular
  The Specular section provides controls for determining the characteristics of light that reflects toward the viewer. These controls affect the appearance of the specular highlight that appears on the surface of the object.
  • Specular Color
    Specular Color determines the color of light that reflects from a shiny surface. The more specular a material is, the glossier it appears. Surfaces like plastics and glass tend to have white specular highlights, whereas metallic surfaces like gold have specular highlights that tend to inherit their color from the material color. The basic shader material does not provide an input for textures to control the specularity of the object. Use tools from the 3D Material category when more precise control is required over the specular appearance.
  • Specular Intensity
    Specular Intensity controls how strong the specular highlight is. If the specular intensity texture input has a valid connection, then this value is multiplied by the Alpha value of the input.
  • Specular Exponent
    Specular Exponent controls the falloff of the specular highlight. The greater the value, the sharper the falloff, and the smoother and glossier the material appears. The basic shader material does not provide an input for textures to control the specular exponent of the object. Use tools from the 3D Material category when more precise control is required over the specular exponent.
• Transmittance
  Transmittance controls the way light passes through a material. For example, a solid blue sphere casts a black shadow, but one made of translucent blue plastic would cast a much lower density blue shadow.
  
  There is a separate opacity option. Opacity determines how transparent the actual surface is when it is rendered. Fusion allows adjusting both opacity and transmittance separately. This might be a bit counter-intuitive to artists who are unfamiliar with 3D software at first. It is possible to have a surface that is fully opaque but transmits 100% of the light arriving upon it, effectively making it a luminous/ emissive surface.
  • Attenuation
    Attenuation determines how much color is transmitted through the object. For an object to have transmissive shadows, set the attenuation to (1, 1, 1), which means 100% of green, blue, red light passes through the object. Setting this color to RGB (1, 0, 0) means that the material transmits 100% of the red arriving at the surface but none of the green or blue light. This allows “stained glass” shadows.
  • Alpha Detail
    When the Alpha Detail slider is set to 0, the Alpha channel of the object is ignored and the entire object casts a shadow. If it is set to 1, the Alpha channel determines what portions of the object cast a shadow.
  • Color Detail
    The Color Detail slider modulates light passing through the surface by the diffuse color + texture colors. Use this to throw a shadow that contains color details of the texture applied to the object. Increasing the slider from 0 to 1 brings in more of diffuse color + texture color into the shadow. Note that the Alpha and opacity of the object are ignored when transmitting color, allowing an object with a solid Alpha to still transmit its color to the shadow.
  • Saturation
    The Saturation slider controls the saturation of the color component transmitted to the shadow. Setting this to 0.0 results in monochrome shadows.
  • Receives Lighting/Shadows
    These checkboxes control whether the material is affected by lighting and shadows in the scene. If turned off, the object is always fully lit and/or unshadowed.
  • Two-Sided Lighting
    This makes the surface effectively two-sided by adding a second set of normals facing the opposite direction on the back side of the surface. This is normally off, to increase rendering speed, but can be turned on for 2D surfaces or for objects that are not fully enclosed, to allow the reverse or interior surfaces to be visible as well.
    
    Normally, in a 3D application, only the front face of a surface is visible and the back face is culled, so that if a camera were to revolve around a plane in a 3D application, when it reached the backside, the plane would become invisible. Making a plane two sided in a 3D application is equivalent to adding another plane on top of the first but rotated by 180 degrees so the normals are facing the opposite direction on the backside. Thus, when you revolve around the back, you see the second image plane that has its normals facing the opposite way.
    
    Fusion does exactly the same thing as 3D applications when you make a surface two sided. The confusion about what two-sided lighting does arises because Fusion does not cull backfacing polygons by default. If you revolve around a one-sided plane in Fusion, you still see it from the backside (but you are seeing the frontside bits duplicated through to the backside as if it were transparent). Making the plane two sided effectively adds a second set of normals to the backside of the plane.
    
    Note that this can become rather confusing once you make the surface transparent, as the same rules still apply and produce a result that is counterintuitive. If you view from the frontside a transparent twosided surface illuminated from the backside, it looks unlit.
• Material ID
  This control is used to set the numeric identifier assigned to this material. The Material ID is an integer number that is rendered into the MatID auxiliary channel of the rendered image when the Material ID option is enabled in the Renderer 3D tool.

3D Node Common Transform Tab

Many tools in the 3D category include a Transform tab used to position, rotate, and scale the object in 3D space.

• Translation
  • X, Y, Z Offset
    These controls can be used to position the 3D element.
• Rotation
  • Rotation Order
    Use these buttons to select which order is used to apply rotation along each axis of the object. For example, XYZ would apply the rotation to the X axis first, followed by the Y axis and then finally the Z axis.
  • X, Y, Z Rotation
    Use these controls to rotate the object around its pivot point. If the Use Target checkbox is selected, then the rotation is relative to the position of the target; otherwise, the global axis is used.
• Pivot
  • X, Y, Z Pivot
    A Pivot point is the point around which an object rotates. Normally, an object rotates around its own center, which is considered to be a pivot of 0,0,0. These controls can be used to offset the pivot from the center.
• Scale
  • X, Y, Z Scale
    If the Lock X/Y/Z checkbox is checked, a single Scale slider is shown. This adjusts the overall size of the object. If the Lock checkbox is unchecked, individual X, Y, and Z sliders are displayed to allow individual scaling in each dimension. Note: If the Lock checkbox is checked, scaling of individual dimensions is not possible, even when dragging specific axes of the Transformation Widget in scale mode.
• Use Target
  Selecting the Use Target checkbox enables a set of controls for positioning an XYZ target. When target is enabled, the object always rotates to face the target. The rotation of the object becomes relative to the target.
• Import Transform
  Opens a file browser where you can select a scene file saved or exported by your 3D application. It supports the following file types:

The Import Transform button imports only transformation data. For 3D geometry, lights, and cameras, consider using the File > FBX Import option.

Onscreen Transformation Controls
Most of the controls in the Transform tab are represented in the viewer with onscreen controls for transformation, rotation, and scaling. To change the mode of the onscreen controls, select one of the three buttons in the toolbar in the upper left of the viewer. The modes can also be toggled using the keyboard shortcut Q for translation, W for rotation, and E for scaling. In all three modes, individual axes of the control may be dragged to affect just that axis, or the center of the control may be dragged to affect all three axes.

The scale sliders for most 3D tools default to locked, which causes uniform scaling of all three axes. Unlock the Lock X/Y/Z Scale checkbox to scale an object on a single axis only.

3D Node Settings Tab

The Common Settings tab can be found on most tools in Fusion. The following controls are specific settings for 3D nodes.

• Hide Incoming Connections
  Enabling this checkbox can hide connection lines from incoming nodes, making a node tree appear cleaner and easier to read. When enabled, empty fields for each input on a node are displayed in the Inspector. Dragging a connected node from the node tree into the field hides that incoming connection line as long as the node is not selected in the node tree. When the node is selected in the node tree, the line reappears.
• Comment Tab
  The Comment tab contains a single text control that is used to add comments and notes to the tool. When a note is added to a tool, a small red dot icon appears next to the setting’s tab icon and a text bubble appears on the node. To see the note in the Node Editor, hold the mouse pointer over the node for a moment. The contents of the Comments tab can be animated over time, if required.
• Scripting Tab
  The Scripting tab is present on every tool in Fusion. It contains several edit boxes used to add scripts that process when the tool is rendering. For more details on the contents of this tab, please consult the scripting documentation.

About the Author

Justin Robinson is a Certified DaVinci Resolve, Fusion & Fairlight instructor who is known for simplifying concepts and techniques for anyone looking to learn any aspect of the video post-production workflow. Justin is the founder of JayAreTV, a training and premade asset website offering affordable and accessible video post-production education. You can follow Justin on Twitter at @JayAreTV YouTube at JayAreTV or Facebook at MrJayAreTV