fereelder.blogg.se - Z-level shape finishing hypermill tutorial

Z level shape finishing hypermill tutorial how to#

Now we finish the model off with a few more shapes: feet, wheels, and head. Roslaunch urdf_tutorial display.launch model:=urdf/04-materials.urdf You can also use a texture to specify an image file to be used for coloring the object.No one will even complain if you redefine it though. You could also define the material tag from within the visual element, and even reference it in other links.

This material is then referenced by the base_link's visual element. We’ve defined a new material called “blue”, with the red, green, blue and alpha channels defined as 0,0,0.8 and 1 respectively. My robot and R2D2 are not red!” That’s a good point. “That’s very cute, but not everyone owns a B21. If a TF frame does not exist for a given URDF link, then it will be placed at the origin in white (ref. Rviz uses this information to figure out where to display each shape.

The launch file runs packages that will create TF frames for each link in your model based on your URDF.

Roslaunch urdf_tutorial display.launch model:=urdf/03-origins.urdf

And since we want the long part of the leg to be parallel to the z axis, we rotate the visual part PI/2 around the Y axis. Since we want the leg to attach at the top, we offset the origin down by setting the z offset to be -0.3 meters. This defines where the center of the visual element should be, relative to its origin.

Now, looking at the leg’s visual origin, it has both a xyz and rpy offset.

Since we didn’t specify a rpy (roll pitch yaw) attribute, the child frame will be default have the same orientation as the parent frame. This means that the origin for the child link will be up and to the right, regardless of the child link’s visual origin tag. So we are -0.22 meters in the y direction (to our left, but to the right relative to the axes) and 0.25 meters in the z direction (up). It is defined in terms of the parent’s reference frame.

Let’s start by examining the joint’s origin.

Also, it doesn’t attach to the middle of the leg, it attaches to the upper part, so we must offset the origin for the leg as well. So that’s where we specify the origin of the JOINT to be. R2D2’s leg attaches to the top half of his torso, on the side. If we want them not to overlap we must define more origins. Roslaunch urdf_tutorial display.launch model:=urdf/02-multipleshapes.urdfīoth of the shapes overlap with each other, because they share the same origin. This means that the leg’s position is dependent on the base_link’s position. URDF is ultimately a tree structure with one root link.

The joint is defined in terms of a parent and a child.

Note how we defined a 0.6m x 0.1m x 0.2m box.

We’ll start with inflexible, or fixed joints. Joint elements can refer to both flexible and inflexible joints. If we just add more link elements to the urdf, the parser won’t know where to put them.

Z level shape finishing hypermill tutorial how to#

Now let’s look at how to add multiple shapes/links. Hence, half the cylinder is below the grid. The visual element (the cylinder) has its origin at the center of its geometry as a default.Here, it’s a frame defined by our one link, base_link. The fixed frame is the transform frame where the center of the grid is located.You'll have to change all example roslaunch lines given in these tutorials if you are not running them from the urdf_tutorial package location.Īfter launching display.launch, you should end up with RViz showing you the following: Note the single quotes around the argument value. If that is not the case, the relative path to 01-myfirst.urdf will not be valid, and you'll receive an error as soon as roslaunch tries to load the urdf to the parameter server.Ī slightly modified argument allows this to work regardless of the current working directory: $ roslaunch urdf_tutorial display.launch model:='$(find urdf_tutorial)/urdf/01-myfirst.urdf' Note that the roslaunch line above assumes that you are executing it from the urdf_tutorial package directory (ie: the urdf directory is a direct child of the current working directory). Runs nodes to publish sensor_msgs/JointState and transforms (more on these later) Loads the specified model into the parameter server.To examine the model, launch the display.launch file: $ roslaunch urdf_tutorial display.launch model:=urdf/01-myfirst.urdf This may seem like a lot of enclosing tags for a simple “hello world” type example, but it will get more complicated, trust me. part), whose visual component is just a cylinder 0.6 meters long with a 0.2 meter radius. To translate the XML into English, this is a robot with the name myfirst, that contains only one link (a.k.a.