Implementation:Google deepmind Mujoco Engine Init
| Knowledge Sources | |
|---|---|
| Domains | Physics Simulation, Initialization |
| Last Updated | 2026-02-15 04:00 GMT |
Overview
Implements default initialization functions for MuJoCo solver parameters, simulation options, visual settings, statistics, and length-range computation options.
Description
This file provides the functions that set all major MuJoCo configuration structures to their default values. mj_defaultSolRefImp sets default solver reference and impedance parameters (timeconst, dampratio, dmin, dmax, width, midpoint, power). mj_defaultOption initializes the full mjOption structure with default timestep (0.002), gravity (-9.81 in z), solver selection (Newton), integrator (Euler), tolerance parameters, and discrete option flags. mj_defaultStatistic sets default extent, mean inertia, mass, and size values. mj_defaultVisual configures the comprehensive mjVisual structure including camera FOV, rendering quality (shadow size, offscreen samples), headlight parameters, depth mapping ranges, scale factors for visual elements, and RGBA colors for all visualization categories. mj_defaultLROpt sets options for actuator length-range computation.
Usage
Called during model compilation and initialization to establish baseline configuration before user-specified overrides are applied.
Code Reference
Source Location
- Repository: Google_deepmind_Mujoco
- File: src/engine/engine_init.c
- Lines: 1-246
Key Functions
// Solver parameter defaults
void mj_defaultSolRefImp(mjtNum* solref, mjtNum* solimp);
// Simulation option defaults
void mj_defaultOption(mjOption* opt);
// Statistics defaults
void mj_defaultStatistic(mjStatistic* stat);
// Visual defaults
void mj_defaultVisual(mjVisual* vis);
// Length-range computation defaults
void mj_defaultLROpt(mjLROpt* opt);
Import
#include "engine/engine_init.h"
I/O Contract
Inputs
| Name | Type | Required | Description |
|---|---|---|---|
| solref | mjtNum* | No | Solver reference parameters array to initialize (size 2) |
| solimp | mjtNum* | No | Solver impedance parameters array to initialize (size 5) |
| opt | mjOption* | Yes | Simulation options structure to fill with defaults |
| vis | mjVisual* | Yes | Visual settings structure to fill with defaults |
| stat | mjStatistic* | Yes | Statistics structure to fill with defaults |
Outputs
| Name | Type | Description |
|---|---|---|
| opt | mjOption* | Fully initialized simulation options (timestep=0.002, gravity=-9.81, Euler integrator, Newton solver) |
| vis | mjVisual* | Fully initialized visual settings (FOV=45, shadow=4096, all colors set) |
| stat | mjStatistic* | Initialized statistics (extent=2, meaninertia=1, meanmass=1) |