Protocol Documentation

pd3/proto/study.proto

Burgers vectors are expected to be expressed in terms of lattice points and a ratio.

Field	Type	Description
inv_scale	int32	A ratio of 1/inv_scale is applied to the Burgers vector value.
miller	Miller

A list of edges/links/segments describing the DD graph.

Field	Type	Description
leading	int64	The relative leading node. This should index into State.nodes.
trailing	int64	The relative trailing node. This should index into State.nodes.
normal	Miller	Stacking fault normal of this segment.
burgers	Burgers	Burgers vector of this segment.
plane	Miller	Burgers vector of this segment.
periodicity_cell	int32	How this link is reflected if it is periodic.
slip	int32	The slip system of this segment. Note this is set for paradis outputs, but not always pd3 outputs.

Miller indices are typically 1x3 in cubic systems and 1x4 in hexagonal systems. Currently hexagonal implementations are not supported.

Field	Type	Description
indices	int32

Marks a position in space, and a NodeType.

A list of precipitates for the given study.

All simulation states.

Field	Type	Description
nodes	State.NodesEntry	Hash map of id to node. Id can be arbitrary, and in the current implementation is the raw pointer of the pd3::Node.
links	Link
time	double	The simulation time of this state from simulation start.

Field	Type	Description
key	int64
value	Node

Node Type determines particular node behavior. There is a corollary in pd3::NodeType

Name	Number	Description
IMMOBILE	0	Node should not move. Note, this is not fully physical, but very useful.
MOBILE	1	Node is capable of moving.
PLACEHOLDER	2	Used internally, marks a trial segment. Do not use.

Denotes the type of precipitate interaction.

Name	Number	Description
CIRCULAR_PRECIPITATE	0	This comes from Ahmed's work.
ENERGY_PRECIPITATE	1	Method first introduced in pd3, that uses the quasi-static time step to resolve the energy difference in shearing, thus determining the amount of shearing allowed.

.proto Type	Notes	C++	Python
double		double	float
float		float	float
int32	Uses variable-length encoding. Inefficient for encoding negative numbers – if your field is likely to have negative values, use sint32 instead.	int32	int
int64	Uses variable-length encoding. Inefficient for encoding negative numbers – if your field is likely to have negative values, use sint64 instead.	int64	int/long
uint32	Uses variable-length encoding.	uint32	int/long
uint64	Uses variable-length encoding.	uint64	int/long
sint32	Uses variable-length encoding. Signed int value. These more efficiently encode negative numbers than regular int32s.	int32	int
sint64	Uses variable-length encoding. Signed int value. These more efficiently encode negative numbers than regular int64s.	int64	int/long
fixed32	Always four bytes. More efficient than uint32 if values are often greater than 2^28.	uint32	int
fixed64	Always eight bytes. More efficient than uint64 if values are often greater than 2^56.	uint64	int/long
sfixed32	Always four bytes.	int32	int
sfixed64	Always eight bytes.	int64	int/long
bool		bool	boolean
string	A string must always contain UTF-8 encoded or 7-bit ASCII text.	string	str/unicode
bytes	May contain any arbitrary sequence of bytes.	string	str