Prelude | A Quick Start for the Impatient User
Introduction
Thank you for your interest in Virtual CRASH software! You’ll find that Virtual CRASH is an extremely powerful and versatile simulation tool, which can be quickly mastered [1]. This prelude is designed for users (or trial version testers) eager to dive into the Virtual CRASH environment and start manipulating vehicles. You will learn how to select a car from the assets browser and import it into the scene. You’ll also discover how to set up a simulation and attach a vehicle to an animation path. First, let’s cover a few basic aspects of the user interface.
Virtual CRASH 6
This User’s Guide is intended for Virtual CRASH 6 users. Notice, many of the workflows are the same as those found in Virtual CRASH versions 3, 4, and 5.
GPU vs CPU Rendering | A Note to Upgraders
If you're coming from a prior version of Virtual CRASH and are accustomed to using our CPU-based render engine (via the teapot icon or animation menu) to create your videos and diagrams, you will love the new GPU-based Lightspeed Realtime Render Engine. This new GPU-based render engine allows users to produce diagrams and videos at nearly identical quality, but at speeds 150 times faster.
To learn more about the Lightspeed Realtime Render Engine see Chapter 3 and Chapter 5 of the User’s Guide.
Trial Version Limitations
If you have not yet purchased a license of Virtual CRASH software, you will notice the application launches in “trial” mode. You’ll see “trail version” at the top of the application window. Please note, the trial version of Virtual CRASH is designed to give you a feel for its most important features and functions; as such, many features and functions are disabled. You will not be able to save projects, create videos, modify vehicle parameters, among others. While you can experiment with our “generic” vehicle and human figures (multibodies), changing weights and geometrical input data is not possible.
USB Dongle
For each license of Virtual CRASH that is purchased, your organization will receive a physical USB dongle (“license key”). Note, this is not a hardware storage device, but a “key” to unlock Virtual CRASH software functionality. We require that Virtual CRASH software be installed locally on the same Windows desktop or laptop computer to which the display (monitor(s)) and user input devices (mouse and keyboard) used to operate Virtual CRASH are directly connected. The USB dongle must be plugged into this exact same local computer and cannot be used on a remote machine or through a network connection (see EULA). USB-to-IP Windows applications can disrupt the proper functioning of the Virtual CRASH USB dongle and may cause Virtual CRASH to launch only in trial mode. With the trial version launched, once a USB dongle is plugged into the user’s machine, all functionality will be enabled.
Changing Themes
You can change the theme used by Virtual CRASH 6 by going to Window > Theme. The theme used for the images below is “NV Dark”.
Font and Icon Size
The font and icon sizes can be increased by going to Window > Set Font.
Use the pop-up horizontal slider to set the font and icon sizes as needed.
Unit Preferences
When you first start Virtual CRASH 6, speed units are set to kilometers per hour, length in meters, and mass/weight in kilograms. To change the units, simply left-click on the “units” menu in the left-side control panel. Then, left-click on the type of parameter (velocity (speed), metric (length), mass (weight)) to access the dropdown menu, and select the desired unit. These preferences will be automatically saved for future sessions.
Camera Basics
When you first launch Virtual CRASH, the mouse cursor will start in “Pan” mode. “Pan” mode allows you to move the camera carefully throughout the scene, ensuring that you don’t accidentally disturb a simulation by moving or reorienting objects in a project. You will know you are in “Pan” mode when the white glove icon appears in the workspace. With this icon visible, hold+left-click and drag to translate the camera, and hold+right-click and drag to rotate the camera. Use your mouse’s scroll wheel to zoom in and out.
The Virtual Tutor
The Virtual Tutor will assist you in understanding how to access most functions within Virtual CRASH. It does this by literally taking control of your mouse to show you the way! To access the Virtual Tutor help topics, navigate to the lower portion of the left-side control panel and left-click on “help”.
Now you should see a list of topics from which you can select. Note, the "player speed" option is above the list and can be used to slow down or speed up the lessons.
Next, select your lesson by double left-clicking a topic and watch the tutorial.
Select a Vehicle and Place it into the Scene
To place a vehicle into the scene, first left-click on "assets" in the left-side control panel. This action will open the asset browser. The asset browser contains a list of all 3D vehicles, 2D vehicle icons, signs, textures, and other objects that can be placed within the scene [2]. For trial version users, the assets browser can also be used to see what vehicles come with Virtual CRASH.
The asset browser is divided into two sections. The upper half allows you to use a hierarchy to search by object type or vehicle make. The lower half displays the vehicles or other objects that fall within the selected category. For example, when the asset browser opens, the "medium" category is selected by default. "Medium" indicates that the level of vehicle detail is medium to high. Hover your mouse cursor over the area shown in the red box below and use your scroll wheel to scroll up or down the list of vehicle makes. Then, left-click on the desired vehicle make.
Next, position your mouse cursor in the lower half of the asset browser window. Use your mouse’s scroll wheel to scan up and down through the window. You will see images of the available models. If you want to view all models without filtering by make, then left-click on "medium" in the upper half.
Hold+left-click on either the vehicle graphic or the database icon in the upper-right corner of the vehicle graphic, then drag your cursor into the workspace and release the left button. An instance of the vehicle should appear in the workspace. Using this method, you can create as many instances of the vehicle as needed (cloning vehicles is discussed in other chapters). After you have finished placing vehicles in the scene, left-click on "edit".
By hovering over the database icon in the upper right cover of each vehicle, you can see various specifications, including the vehicle’s year.
Below is the trial version’s “generic” vehicle. You are limited to using only this vehicle in the trial version.
Simulation
Input vehicle position
Simulated vehicle controls are fully explained in the User’s Guide. Below, we’ll provide a brief explanation for inputting speed and steering inputs into a simulated vehicle. Again, in the trial version, you will be limited to the “generic” vehicle. To simulate vehicle motion, first change your mouse cursor control to "Select And Move". Then, left-click on the name of your vehicle in the project menu on the left to select it, or you can left-click directly on the vehicle object within the workspace. Next, hold+left-click near the center of the vehicle’s bounding box to reposition the vehicle.
To translate the vehicle, hover your mouse near the center of the vehicle’s bounding box in the workspace. Then, hold+left-click and move your mouse to reposition the vehicle within the workspace, and release the click once it's in the desired position.
Input orientation
To rotate the vehicle, hover your mouse near a corner of the vehicle’s bounding box in the workspace. Then, hold+left-click and move your mouse upward or downward to rotate the vehicle.
Input initial speed
Left-click on the "dynamics" menu in the left-side control panel. You can set the vehicle’s initial speed using the "v (t=0s)" input field. Left-click in the box to the right of this label, type in the initial speed, and press enter. The simulation will instantly refresh, showing the time-forward projected path of the vehicle with a red center-of-gravity line, as well as gray rectangles called "interpositions".
Alternatively, as with many input fields, you can left-click on the down arrow to the right of the input field to open the horizontal slider. Once the slider is open, hover your mouse cursor over it. Then, hold+left-click on the slider button and move your mouse left or right to interactively change the input value. You can also use your mouse’s scroll wheel while your cursor is hovering over the horizontal slider window. When active, the window will change colors to indicate its active state.
Input Driver Actions
Left-click on "dynamics" to close the menu. Then, left-click on "sequences" to open the "sequences" menu, where driver actions can be programmed. Left-click on "add sequence" to input the first driver action. Clicking the "add sequence" button will add an entry to the sequences list, with the default type being "deceleration" (note: sequence types are explained in subsequent chapters). The first entry in this list always relates to the initial driver action, starting at simulation time = 0 seconds. In the example below, we modify the steering angle using the "steering" input field, enabling the driver to initiate a right steering maneuver starting at time = 0 seconds. The "steering time" is the duration for the steering angle to reach the new target angle (note: the default value is always 1 second). In this example, it takes 1 second for the steering angle to change from 0 degrees to -8 degrees at the axle.
Next, we’ll activate the brakes by adding a second sequence. Do this by clicking the "add sequence" button. Then, use the down arrow to interactively adjust the "pedal position" (which represents the percentage of full braking) to decelerate the vehicle.
Note that as you modify any of the sequence inputs, the simulation will instantly refresh, providing an updated time-forward trajectory prediction.
Since the sequence is of "type: deceleration", increasing the "pedal position" input value will decelerate the vehicle. Conversely, if the type is set to "type: acceleration", the "pedal position" will cause the vehicle to accelerate.
You have the flexibility to add as many sequence entries as necessary for your simulation. Additionally, you can left-click on any entry in the sequences list to adjust the various input values as required. The simulation will automatically update to reflect these changes.
Sequence Inputs using Fast-control icons
An alternative to manually inputting sequence entries is to use the fast-control icon input option. To utilize this feature, switch your mouse cursor control to "Select, Move And Manipulate" (or press [F3]). Then, hover over the interposition where you want the driver to initiate the new action and left-click. This action will snap the time-slider to the moment corresponding to the vehicle's position where you clicked. You should then see yellow icons appear.
Hold+left-click on the steering wheel fast control icon to simultaneously change the "steering time" and "steering" input values. Notice that as soon as you move the steering wheel fast-control icon, a sequence is automatically placed in the sequences list. As you move the icon, the trajectory prediction will refresh automatically, and the input values in the corresponding sequence entry will update automatically.
To input another driver action, hover your cursor over the interposition where you want the action to begin and left-click. You will once again see fast-control icons appear. In this example, we used hold+left-click to move the "pedal position" fast-control icon backward, initiating a braking action at that position. Notice that a third sequence entry is automatically placed in the sequences list. The "pedal position" input value for this entry will change as you move the pedal position icon.
Additionally, at each position where a driver action starts, a gray bounding box becomes visible. Each of these bounding boxes corresponds to a specific sequence entry in the sequences list.
Again, you are free to click on any entry in the sequence list to modify the various input values as needed. Additionally, you can left-click on any of the gray bounding boxes to access the corresponding sequence entry. Doing so will reveal the fast-control icons, which you can adjust as needed to fine-tune the simulated motion of the vehicle.
Adjusting Time of Driver Action
The position in space or the corresponding moment in time at which a given action begins is determined by the "time" input value of the sequence entry. "Time" represents the duration after the start of the previous sequence entry when the driver initiates the new action. The first sequence entry always begins at time = 0 seconds. The "time" values for all other sequences can be adjusted as needed by modifying the "time" input field. Additionally, "time" can be interactively adjusted using the "I" fast-control icon. Simply hold+left-click on the "I" icon and drag your cursor backward or forward along the vehicle’s trajectory.
Next, we will begin a new project by selecting Project > New. Then, we'll place a new vehicle into the scene to explore the Path Animation feature.
Path Animation | Link Vehicle to Animation Path
To set your vehicle in motion, you first need to link it to an animation path. To do this, navigate to Create > Animation > Animation Path and left-click. This will activate the Path Animation tool.
Next, hover your mouse over the vehicle you want to link to an animation path. The vehicle will turn light blue in response. Then, left-click on the vehicle to link it to your path.
Left-click in the environment to start placing control vertices, which shape the animation path. To place the final control vertex, right-click in the scene. Then, right-click again to fully terminate the Path Animation creation process.
To view the control vertices (CVs), change your mouse cursor control to "Select, Move And Manipulate" (or press [F3] on your keyboard). The CVs will appear as yellow dots. You can adjust the animation path trajectory by left-clicking, holding, and dragging these CVs with your mouse as needed.
To see the various settings that control the linked vehicle’s behavior, left-click the “edit” button in the left-side control panel. Next, left-click on the name of the animation path shown in the project menu. Once the animation path is selected, you should see its properties appear under “properties”. Here we highlight the animation path’s “sequences” menu, which controls the progression of kinematics inputs for the linked vehicle.
The Path Animation tool will be described in more detail in the chapters below.
Additional Information for Trial Version Users
You can find additional information about typical Virtual CRASH workflows below. If you are using the trial version (without a USB dongle plugged into your machine), please remember while you can experiment with some aspects of the functionality described in the links below, you will not be able to take full advantage of the features until you purchase a full license.
Other important aspects of the Virtual CRASH interface >
Importing total station and RTK Data >
Integration of assets from Photogrammetry >
Physics Tests for Trial Version Users
If you are still test driving the Virtual CRASH trial version, we invite you to head over to the Trial Version Analyses Quick Reference Page to find various videos exploring aspects of the underlying Virtual CRASH physics engine. Note, these videos were made in previous version of Virtual CRASH, but the workflows and interface related to physics inputs are exactly the same as in Virtual CRASH 6.
Additional Training Content
You can find additional training content online at http://www.vcrashusa.com/academy. There you will find Blog posts, Knowledge Base posts, and training videos all of which are important to learn the numerous features and functions of Virtual CRASH. Users are strongly recommended to review all this content on the academy.
Self-Paced Training
Another great way to quickly learn Virtual CRASH fundamentals is by enrolling in our Self-Paced Training courses. In our Self-Paced Training you will receive video lectures specifically made for each course, as well as refreshers of content that can be found on the vCRASH Academy. After watching and reading through the course material, you will be given quizzes and class projects. The class projects are graded by our expert instructors. To learn more about Self-Paced Training go to: http://www.vcrashusa.com/self-paced-training.
Live Training
We offer many live training opportunities throughout the year. Check our calendar for upcoming classes. Check calendar >
Backward Compatibility
Virtual CRASH 6 can import vcm files created in Virtual CRASH 5, 4, and 3. Therefore, previously created vehicle meshes can be reused in Virtual CRASH 6, with the added benefit of advanced material properties which can be specified either with the model’s mtl file or manually. Note, Virtual CRASH 6 does not open vc5, vc4, or vc3 files.
Notes:
[1] When using any accident reconstruction software tool, it is imperative the user perform all necessary consistency checks to ensure the simulated results are in good agreement with expectations from standard forensic techniques. It is also imperative the user understand the limitations of the software tool, as well as understand potential sources of uncertainties in depicted results, including but not limited to, user uncertainties in input parameters as well as those related to object positions and orientations within the project environment.
[2] It is recommended to always consult this list first before starting a project to find the best matches for your subject vehicles. Note, it is also recommended that you ensure all vehicle properties, including size, inertial properties, wheel placement, drive axle, etc, are properly set using appropriate values for your subject vehicles. Vehicle properties can be obtained through third-parties such as the Canadian Vehicle Specifications database (http://www.carsp.ca/research/resources/safety-sources/canadian-vehicle-specifications/), Expert Autostats (http://www.4n6xprt.com/), or Lightpoint Scentific (http://lightpointdata.com/).
Tags: Quick start, animation path, how to watch tutorial, virtual tutor, make a vehicle, put vehicle in scene, how to make an animation, gallery, simulations.
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