We need both thickness and material_thickness to separate the contact thickness computation and the material contact computation.
Without material_thickness, we fall back to use thickness; otherwise, use material_thickness to compute mass/volume/ ..., which can decouple the material behaviour and the contact.
Because in some assets, the mesh quality forces us to use a small thickness, but we still want to keep the elastic behaviour consistent.
We need both
thicknessandmaterial_thicknessto separate the contact thickness computation and the material contact computation.Without
material_thickness, we fall back to use thickness; otherwise, usematerial_thicknessto compute mass/volume/ ..., which can decouple the material behaviour and the contact.Because in some assets, the mesh quality forces us to use a small thickness, but we still want to keep the elastic behaviour consistent.