A resource that holds a stack of [SkeletonModification3D]s. This resource is used by the Skeleton and holds a stack of [SkeletonModification3D]s. The SkeletonModificationStack3D controls the order of the modifications, which controls how they are applied. Modification order is especially important for full-body IK setups, as you need to execute the modifications in the correct order to get the desired results. For example, you want to execute a modification on the spine [i]before[/i] the arms on a humanoid skeleton. Additionally, the SkeletonModificationStack3D also controls how strongly the modifications are applied to the [Skeleton3D] node. Adds the passed-in [SkeletonModification3D] to the stack. Deletes the [SkeletonModification3D] at the index position [code]mod_idx[/code], if it exists. Enables all [SkeletonModification3D]s in the stack. Executes all of the [SkeletonModification3D]s in the stack that use the same execution mode as the passed-in [code]execution_mode[/code], starting from index [code]0[/code] to [member modification_count]. [b]Note:[/b] The order of the modifications can matter depending on the modifications. For example, modifications on a spine should operate before modifications on the arms in order to get proper results. Returns a boolean that indiciates whether the modification stack is setup and can execute. Returns the [SkeletonModification3D] at the passed-in index, [code]mod_idx[/code]. Returns the [Skeleton3D] node that the SkeletonModificationStack3D is bound to. Sets the modification at [code]mod_idx[/code] to the passed-in modification, [code]modification[/code]. Sets up the modification stack so it can execute. This function should be called by [Skeleton3D] and shouldn't be called unless you know what you are doing. When true, the modification's in the stack will be called. This is handled automatically through the [Skeleton3D] node. The amount of modifications in the stack. The interpolation strength of the modifications in stack. A value of [code]0[/code] will make it where the modifications are not applied, a strength of [code]0.5[/code] will be half applied, and a strength of [code]1[/code] will allow the modifications to be fully applied and override the skeleton bone poses.