Help Cloth to simulate slime

[akayashi1212]

This isn't really related to Obi, it's basic math. If you want to have an ellipsoidal shape for the user's finger, you can use an anisotropic support function (as opposed to an isotropic one). This is just math lingo for a shape that's not radially symmetric, like a circle. So what you do is calculate the distance from the user's finger to all particles, pass the distance to your support function, and it will tell you which particles to move and how much. I can't really be more specific without writing the code for you.

You can increase the cloth's compliance (expressed in meters/newton). That will make it more elastic. See:
http://obi.virtualmethodstudio.com/tutor...aints.html


The video shows a circular shape when the user presses. This can be accomplished simply by calculating the distance from every particle to the user's finger, then moving these particles closer than a distance. All you need to do is iterate trough the solver.positions array and use Vector3.Distance with each one, should be very simple:

Code:

for (int i = 0; i < cloth.solverIndices.Length; ++i)
{
    int solverIndex = cloth.solverIndices[i];
    float distance = Vector3.Distance(cloth.solver.positions[solverIndex], <user finger>);

    //use your support function here, for instance a step function with radius 0.7:
    if (distance < 0.7f)
    {
    // move particle
    }
}

kind regards,

Thank you very much for detailed reponse! But again, i mean i stuck at "move particle", not at select particle. i've tried move down the particle by change Y position like this code: "solver.positions[solverIndex] = new vector4(solver.positions[solverIndex][0], -2f,solver.positions[solverIndex][2],solver.positions[solverIndex][3])" and it very glitchy like the video. when i change particle velocity or externalForce, all particle in cloth move down too @@. Now i'm thinking about move particle to around finger shape ( by X and Z position) instead of move below finger shape ( Y position). Then, all i want to ask is: have any functions/parameters in Obi's API support me do it? thank you again for the best support ^^.