How to get the phyiscal parms in MPM

[zhaohaoyu376]

In demo.py, the physical parameters in MPM are directly using the default values from material_params. However, the article mentions that these parameters are computed using SVD? Could you tell me where the code for calculating the physical parameters is?

        material_params = {
            # select from jel
            "material": "jelly",  # "jelly", "metal", "sand", "foam", "snow", "plasticine", "neo-hookean"
            "g": [0.0, 0.0, 0.0],
            "density": 2000,  # kg / m^3
            "grid_v_damping_scale": 1.1,  # no damping if > 1.0
        }
        self.material_name = material_params["material"]
        mpm_solver = MPMWARPDiff(
            num_particles, n_grid=grid_size, grid_lim=1.0, device=device
        )
        mpm_solver.set_parameters_dict(mpm_model, mpm_state, material_params)

[a1600012888]

Hi

The default material params in the above code is density. In simulation there is a scale ambiguity. (because you don't know the exact scale of physical size, the physical force), so it's common to set the density as a fixed variable to remove such scale ambiguity. Only the Young's modulus is optimized.

Thanks,

[zhaohaoyu376]

Hi, But it seems all the material parms are default? I can’t find the code to optimize the Young's modulus by SVD. Best, Haley ---- Replied Message ---- FromTianyuan @.>Date09/20/2024 01:22 @.> CcHaoyu @.>, @.>SubjectRe: [a1600012888/PhysDreamer] How to get the phyiscal parms in MPM (Issue #19) Hi The default material params in the above code is density. In simulation there is a scale ambiguity. (because you don't know the exact scale of physical size, the physical force), so it's common to set the density as a fixed variable to remove such scale ambiguity. Only the Young's modulus is optimized. Thanks, — Reply to this email directly, view it on GitHub, or unsubscribe. You are receiving this because you authored the thread.Message ID: @.***>

[zhaohaoyu376]

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Hi,I can not find the code to  optimize Young's modulus. This code is not open?Bayou

                    709436780

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        Tianyuan ***@***.***>

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    09/20/2024 01:22

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          Re: [a1600012888/PhysDreamer] How to get the phyiscal parms in MPM (Issue #19)

Hi The default material params in the above code is density. In simulation there is a scale ambiguity. (because you don't know the exact scale of physical size, the physical force), so it's common to set the density as a fixed variable to remove such scale ambiguity. Only the Young's modulus is optimized. Thanks,

—Reply to this email directly, view it on GitHub, or unsubscribe.You are receiving this because you authored the thread.Message ID: @.***>