A number of specialized tools are available to help simulate most types of earthmoving equipment and operations.

• The Bucket tool represents the bucket appendage on an excavator-type vehicle. It can dig up soil from an Earthwork Zone or from a soil bin, carry it to another zone or soil bin, and then pour it out.

• The Blade tool represents the blade on the front of a bulldozer-type vehicle. It cannot pick up soil, but can displace it (push it) to an adjacent portion of an Earthwork Zone or a Soil Bin.

• The Generic Bucket tool represents the wide bucket appendage on wheel loaders and other types of earthmovers. It is similar in function to the bucket tool, but its shape can be customized to match the real thing.

Note In some cases, it may be useful to disable the ability of the above tools to deform soil. For a bucket, select the Dynamics Bucket in the Explorer panel. In the resulting Properties panel, deselect the checkbox located next to "Inputs".For a blade, select the Dynamics Blade in the Explorer panel. In the resulting Properties panel, deselect the checkbox located next to "Inputs".For a generic bucket, select Generic Bucket > Bucket Face in the Explorer panel. In the resulting Properties panel, deselect the checkbox located next to "Inputs". It is not recommended to toggle this option while the tool is in contact with a soil surface.

Bucket

A bucket is a type of Earthwork deformation tool that is set up in a mechanism. It is a box-like structure used to scoop up soil, e.g., the bucket of an earthmoving excavator.

Before adding a bucket to a mechanism, the latter should first be created with all the relevant parts, constraints and logic.

To add a Bucket extension:

1. In your mechanism, select Earthwork Systems in the Toolbox.

2. Double-click Bucket to add one to your mechanism, or drag it into the 3D View.

A bucket icon appears under the mechanism in the Explorer panel. This extension contains the physical parameters of the bucket.

The next step is attaching the bucket to the corresponding part and graphics node of the mechanism. Once they are properly attached to the mechanism, we will configure the four Bucket Tool extensions in order to ensure that their related properties use the correct position, orientation, shape and size values when calculating contact, or rendering soil materials.

Attaching the Bucket to a Part

1. From the Explorer panel, click the bucket. The bucket properties appear in the Properties panel.

2. Under the Parameters section near the bottom, click the Browse button in the Part field, then

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3. From the Explorer Panel of your mechanism, go into the Assembly, then locate and click on the Part that you've set up for the bucket of the mechanism.

4. The part's name appears in the Select Part dialog box. Click the Confirm button.

The bucket part's name now appears in the parameter box and the bucket accessory position is now relative to the bucket part's origin.

Configuring the Bucket Extension

After connecting the bucket part and node to the Bucket extension, the accessories are now clustered around the bucket's origin. We need to modify the values so the bucket will be positioned correctly.

1. From the Explorer panel, click the bucket. The bucket properties appear in the Properties panel.

2. Ignore the Inputs and Outputs sections and go directly to the Parameters section.
   
   

3. Configure the fields below.
   
   

   • Material: Type the name of the material you want to use for the bucket in the Material text box (e.g., a bucket material was created for the Excavator demo scene).

   • Part: This is the part for the bucket that was attached in the previous step.

   • Shape Model: Modify the values in the Shape Model parameters of the bucket until it takes on the dimensions, position and orientation of the bucket's 3D model.

Blade

The blade tool is a generic, user-customizable surface that can push soil around. It can be used to model most types of dozer blades.

Unlike the bucket, which has a very specific shape, the Blade tool gives you complete control over the shape of the deformation tool, so you could design any number of flat or angled blades with which a vehicle might use to push soil around or build a trench.

Note A ripper cannot be accurately represented with the Blade extension, because it is thin and induces a significant outward soil flow during cutting. The cutting force of the blade is computed with a model which is applicable only to wide blades with a high width-to-depth ratio, or cutting tools with side walls which prevent any lateral soil flow.

Before adding a Blade extension to a mechanism, the latter should be first created with all the relevant parts, constraints and logic. You will need to define the collision geometries that determine the shape of the blade; for example, if creating a standard bulldozer blade, you might define five box shapes, two for the side walls, one for the bottom, and two for the largest part of the blade. The excavator blade shown below has four box collision geometries, with no side walls. When creating the CGs, it is a good practice to give them clear names.

To add a Blade extension:

1. In your mechanism, select Earthwork Systems in the Toolbox.

2. Double-click Blade to add one to your mechanism, or drag it into the 3D View.

A new extension with a blade icon appears under the mechanism in the Explorer panel, with no accessory shown in the 3D Viewport (yet). It contains the physical parameters of the blade.

Configuring the Blade Extension

The next step is to connect the blade part and the collision geometries to the Blade extension, specify the material to use, and disable collisions on the collision geometries.

From the Explorer panel, click the Blade extension. The Blade properties appear in the Properties panel.

• Material: Type the name of the contact material you want to use for the blade in the Material text box (for example, the Bucket material was used for the Excavator demo scene).

• Part: This is the reference Part for the blade.
  Click the Browse, then

  . From the Explorer panel of your mechanism, go into the assembly, then locate and click on the part that you have set up for the blade of the mechanism. The part's name appears in the Select Part dialog box. Click the Confirm button. The blade part's name now appears in the parameter box.

• Template CGs: This section has two parameters, size and collision geometry fields. Size specifies the number of collision geometries you want to use (this can be changed later if need be).
  For each collision geometry field, click the Browse button, then

  
  in the numbered reference box. The Select (Number) dialog box appears. From the Explorer panel of your mechanism, go into the assembly, locate the part that you have set up for the blade, then click on its collision geometry. The name of the collision geometry appears in the numbered reference box. Click the Confirm button, and repeat the operation for the next collision geometry field.
  While selecting the various collision geometries in the Blade extension, they will be highlighted in blue on the blade part.

Generic Bucket

This is a customizable version of the basic bucket. Its shape can be modified to simulate a dragline bucket, or a wheel loader's front bucket, for example.

Before adding a Generic Bucket extension to a mechanism, the latter should first be created with all the relevant parts, constraints and logic. Also, the geometric shape of the bucket should be modeled with a set of collision geometries. We recommend the use of primitive geometries only, such as cylinders for the side walls and boxes to model the general curved shape of the bucket's interior.

To add a Generic Bucket extension:

1. In your mechanism, select Earthwork Systems in the Toolbox.

2. Double-click Generic Bucket to add one to your mechanism, or drag it into the 3D View.

A new Generic Bucket folder appears under the mechanism in the Explorer panel. After creation, the generic bucket already contains a single bucket face. Bucket faces define the side walls of the bucket and are configured analogously to the blade. This extension is used to model the geometric shape of a single face/side of the bucket with which the tool can dig. For example, a wheel loader bucket would require at least three bucket faces: two for the side walls, and one for the curved interior shape and the teeth of the bucket.

By right-clicking on the Generic Bucket folder, it is possible to add more bucket faces:

• Add Bucket Face: Adds another bucket face to the generic bucket, which is modeled by a Blade extension. See above for configuration of the Blade extension.
  Multiple bucket faces are required for pretty much any bucket design (for example, a wheel loader bucket would need three bucket faces at least). It is also used when the bucket is composed of multiple moving parts, but this is a specialized case. In order to measure the payload in the bucket, you can add a Soil Mass Sensor to the generic bucket from the Toolbox. The payload information can be useful for the collection of operator performance metrics.

The right-click menu also offers two additional, though optional features for visualization of the soil in the bucket. For best visual representation of soil, the SSM feature described in the Soil Particles Extension topic should be used instead.

• Add Soil Surface: Adds a Soil Surface folder which contains two extensions, Graphics Soil and Soil Mass Sensor. This is to visualize the soil particles contained in the bucket by wrapping them with a height field mesh.

• Add Particle Effect: Adds a Particle Effect folder which contains two extensions, Particle Spray and Plane Sensor. This is to emit additional visual particles when the dynamics soil particles are being poured out of the bucket.

Note You can also add the Generic Bucket extension to a configuration from the right-click menu.