Chapter 7: Properties editing¶

7.1 Three property entry points¶

Model Define → Global¶

This entry edits scene-level Global Properties and Visual Properties; see Chapter 2. All objects must be deselected first.

3D View property gizmo¶

In Object Mode, select a Forge object and click the colored Gizmo shown next to the object to open its Properties dialog.

Object Properties → Forge Properties¶

This panel displays the active object's:

• Local/World Location and Rotation;
• Dimensions;
• Parent;
• Forge Model Type; and
• model-property data for the current type.

To open the panel:

1. Open the Properties editor .
2. Switch to the Object Properties tab .
3. Expand Forge Properties to show properties for the current Model Type.

7.2 The property gizmo is not visible¶

Check the following in order:

1. The current area is a 3D View and Blender is in Object Mode .
2. Gizmos are enabled in the 3D View .
3. The active object's Blender type and Forge type are correct.
4. A shape object still has the Geometry Nodes Modifier that Forge added during creation.

7.3 Object property dialogs¶

All dialogs below are UI-only Operators intended for interaction through the Blender interface.

Height Field¶

Operator ID: forge.properties_hfield

Dialog:

Plane¶

Operator ID: forge.properties_plane

Visual / Collider¶

Operator ID: forge.properties_shape

• Box: edit X/Y/Z Size.
• Sphere: edit Radius.
• Capsule/Cylinder: edit Radius and Height.
• Mesh: there is no Primitive Size input; edit the Mesh itself or the object dimensions.

Materials are not edited in this dialog. Use Create Material, or assign a material directly in the Blender object material slots.

The Model Properties area stores collision, mass, and Solver parameters for the MJCF Geometry.

Link¶

Operator ID: forge.properties_link

Site¶

Operator ID: forge.properties_shape_site

Inertial¶

Select an Inertial to view mass, diaginertia, and fullinertia under Object Properties → Forge Properties → Inertial Info. This panel is read-only and there is no separate inertia properties dialog. To change values, use the object's Forge_Inertial through Python:

import bpy

inertial = bpy.context.active_object.Forge_Inertial
inertial.mass = 2.0
inertial.fullinertia = (0.2, 0.3, 0.4, 0.0, 0.0, 0.0)

• diaginertia contains the three diagonal components in the principal inertia frame. The object's rotation relative to its parent Link defines the principal axes; its position is the center of mass.
• fullinertia is the symmetric tensor about the center of mass, expressed in Link axes, ordered Ixx, Iyy, Izz, Ixy, Ixz, Iyz. It is derived from the current rotation and diagonal inertia.
• A nonzero fullinertia assignment must be positive definite. Forge decomposes it and updates the principal rotation and diaginertia. Scripts should assign all six components together to avoid incomplete intermediate tensors.
• Changing mass or inertia updates the equivalent box. Preview requires finite positive mass, finite positive diagonal moments, and the inertia triangle inequalities; otherwise it is not drawn.

Joint¶

Operator ID: forge.properties_joint

Actuator¶

Operator ID: forge.properties_actuator

Tendon¶

Operator ID: forge.properties_tendon

Tendon uses + and - to add or remove Target list entries. The Operators are forge.add_tendon_target_item and forge.remove_tendon_target_item. They are UI helper entry points; scripts and MCP should maintain the Tendon Target collection directly.

Equality¶

Operator ID: forge.properties_equality

When Active is disabled, the main Equality parameters cannot be edited.

Contact¶

Operator ID: forge.properties_contact

Only Pair contacts display collision and Solver parameters.

Sensor¶

Operator ID: forge.properties_sensor

Frame Sensor can set Reference. Contact Sensor shows a Link, Geom, Subtree, or Site name according to Target Type.

Light¶

Operator ID: forge.properties_light

Target is shown only for Targetbody/Targetbodycom modes.

Camera¶

Operator ID: forge.properties_camera

Target is shown only for Targetbody/Targetbodycom modes.

Replicate¶

Operator ID: forge.properties_replicate

Dynamic fields:

• Global / Visual: detailed Headlight and SSGI parameters are controlled by their Active switches; disabling them disables the corresponding fields.
• Height Field: Height Map appears only after Use Height Map is enabled.
• Plane: Infinite is independent and does not hide Half Size.
• Visual / Collider: the geometry type determines dimension fields; Box shows three-axis Size, Sphere shows Radius, Capsule/Cylinder show Radius + Height, and Mesh shows no primitive size. Materials are managed through the object's first Material Slot.
• Site: the geometry type determines whether Size, Radius, or Radius + Height is shown.
• Link: Display Type / Display Size / Mocap / Gravcomp are always shown; no fields are hidden by type.
• Joint: Free shows only basic Stiffness / Armature / Damping / Frictionloss. Other types also show Springdamper, Solver, Range, Limited, and related fields. Ball does not show Actuator Force Range/Limited.
• Actuator: Position shows Kp / Kv / Inheritrange, Velocity shows Kv, and Adhesion shows Gain; other types show Gear / Dynamics / Gain / Bias arrays.
• Tendon: the Target field comes from a variable-length Target list controlled by + / -.
• Equality: disabling Active disables all remaining fields. Target 2 appears only after Target 1 is set; the remaining parameters depend on Equality type.
• Contact: only Pair shows Condim, Friction, Solver, Margin, Gap; Exclude does not show them.
• Sensor: a Contact Sensor labels target fields as Link1/2, Geom1/2, Subtree1/2, or Site according to Target Type. Frame sensors show Reference and Use Xbody after Target is set; Contact sensors show Reference and Use Subtree when a second target is required.
• Light: only Targetbody/Targetbodycom shows Target; Spot/Point show Shadow Soft Size / Cutoff Distance, other types show Angle, and Spot additionally shows Spot Size / Spot Blend.
• Camera: only Targetbody/Targetbodycom shows Target; Perspective shows FOV/Angle, while Orthographic shows Ortho Scale.
• Replicate: Count / Offset / Euler appear only while the object still has a Replicate Modifier; Separator always belongs to Replicate properties.

7.4 How changes take effect¶

Property dialogs modify Object, Modifier, or Scene data directly and do not have an Apply/Save button. Changes remain after closing the dialog and can be undone with Blender Undo.

Prefer changing Size, Radius, and Height in Properties. Several Forge objects lock Object Scale; shape dimensions are driven by the Geometry Nodes Modifier parameters.