[SOLVED] How can I add a mesh in SOFA?

[luibass92]

Hi everyone,

In my scene I have an articulated object (/src/examples/Components/mapping/ArticulatedSystemMapping.scn) composed by 4 cuboids linked through some articulations.
I was wondering how can I have some meshes (of which I have the .obj files) instead of that cuboids to link the articulations.

I hope that someone can help me.
Cheers.

[Hugo]

Hi Luigi,

What you want to do is to load a mesh ?
The cuboid is generated in the .scn file by :

<Node name="Visu">
                    <OglModel name="Visual" position="-1 -0.5 -0.5 -1 0.5 -0.5 -1 0.5 0.5 -1 -0.5 0.5 1 -0.5 -0.5 1 0.5 -0.5 1 0.5 0.5 1 -0.5 0.5 -1 -0.5 -0.5 -1 0.5 -0.5 -1 0.5 0.5 -1 -0.5 0.5 1 -0.5 -0.5 1 0.5 -0.5 1 0.5 0.5 1 -0.5 0.5 -1 -0.5 -0.5 -1 0.5 -0.5 -1 0.5 0.5 -1 -0.5 0.5 1 -0.5 -0.5 1 0.5 -0.5 1 0.5 0.5 1 -0.5 0.5 -1 -0.5 -0.5 -1 0.5 -0.5 -1 0.5 0.5 -1 -0.5 0.5 1 -0.5 -0.5 1 0.5 -0.5 1 0.5 0.5 1 -0.5 0.5" triangles="3 1 0 3 2 1 3 6 2 3 7 6 7 5 6 7 4 5 4 1 5 4 0 1 5 1 2 2 6 5 4 7 3 4 3 0 11 9 8 11 10 9 11 14 10 11 15 14 15 13 14 15 12 13 12 9 13 12 8 9 13 9 10 10 14 13 12 15 11 12 11 8 19 17 16 19 18 17 19 22 18 19 23 22 23 21 22 23 20 21 20 17 21 20 16 17 21 17 18 18 22 21 20 23 19 20 19 16 27 25 24 27 26 25 27 30 26 27 31 30 31 29 30 31 28 29 28 25 29 28 24 25 29 25 26 26 30 29 28 31 27 28 27 24" />
                    <RigidMapping template="Rigid3d,ExtVec3f" rigidIndexPerPoint="0 8 8 8 8" input="@.." output="@Visual" />
                </Node>

To replace the cuboid, all you need to do is to set the mesh you want to visualize in the field filename of the OglModel:

    <OglModel name="VisualModel" fileMesh="path_to/my_mesh.obj"/>

and taking care of the rigidIndexPerPoint parameter in the RigidMapping.
Hope this helps,

Cheers,

Hugo

[luibass92]

Thanks for your reply Hugo,

I’ve already solved the problem replacing the “Collision” and “Visu” nodes with the following:

<Node name="Collision">
                    <MeshObjLoader name="MeshLoader"  filename="mesh/base10.obj" scale="100" translation="0 -3 0" rotation="0 0 0"/>
		    <Mesh src="@MeshLoader" /> 
                    <MechanicalObject template="Vec3d" src="@MeshLoader"  />
                    <TriangleModel />
                    <LineModel />
                    <RigidMapping  input="@.." index="0" />
                </Node>
                <Node name="Visu">
                    <OglModel name="Visual" filename="mesh/base10.obj" scale="100" translation="0 -3 0" rotation="0 0 0"/>
                    <RigidMapping template="Rigid3d,ExtVec3f" input="@.." index="0" output="@Visual" />
                </Node>

It worked fine.

Do you know if it is possible to not check collisions between certain parts of the scene?

I’ve created a robotic hand in SOFA made by 5 articulated chains (one for each finger) with all the relative meshes. The problem is that the collision checking algorithm makes the simulation really slow even if I don’t need to check the collisions between one finger and another or between the parts of a single finger, but just with other objects in the scene.

Thanks for your support,

Luigi

[Hugo]

Nice to hear Luigi.

About the collision detection: something easy is just to remove the collision model of some parts (here removing and ).
But what you seem to target is more a specific CollisionPipeline. I think you will have to implement some new pipeline or new collisionListener. Maybe something already exists, I am no expert of collision.

I set the topic as solved, since the problem of mesh is solved.
Do not hesitate to create a new topic for any further question.

[luibass92]

OK, thanks, I will create another topic about collisions

[Author]

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