erwincoumans’s gists

erwincoumans / gist:6666160

Last active January 7, 2024 10:28

Example how to create the A matrix and b vector and solve the LCP using Projected Gauss Seidel for Bullet 2.x. Requires Eigen lib and Bullet 2.82. Note that one of the differences between plain projected Gauss Seidel and the Bullet iterative solver is that the friction limits are computed at each iterations, from the related normal force. (This …

	//#include "Eigen/Dense"
	#include "Eigen/Sparse"

	static Eigen::VectorXf Solve_GaussSeidel (Eigen::MatrixXf & A, Eigen::VectorXf & b, Eigen::VectorXf & lo,Eigen::VectorXf & hi,int kMax = 5)
	{
	//A is a m-n matrix, m rows, n columns
	if (A.rows() != b.rows())
	return b;

	int i, j, n = A.rows();

erwincoumans / dobot.ino

Created March 17, 2016 17:20

Dobot control using RAMPS 1.4 shield with Arduino Mega

	//This is taken from https://www.reddit.com/r/Dobot/comments/45ilan/controlling_dobot_with_ramps_14

	#include <AccelStepper.h>

	#define X_STEP_PIN 54
	#define X_DIR_PIN 55
	#define X_ENABLE_PIN 38
	#define X_MIN_PIN 3
	#define X_MAX_PIN 2

erwincoumans / test.py

Created October 28, 2017 02:08

pybullet concave collision test

	import pybullet as p
	import time
	p.connect(p.GUI)

	#disable rendering during loading speeds it up
	p.configureDebugVisualizer(p.COV_ENABLE_RENDERING,0)
	p.configureDebugVisualizer(p.COV_ENABLE_TINY_RENDERER,0)
	p.loadURDF("ground.urdf",useMaximalCoordinates=True)
	for i in range (10):
	for j in range (10):

erwincoumans / ground.urdf

Created October 28, 2017 02:09

pybullet URDF example of a static concave triangle mesh (non-moving)

	<?xml version="1.0" ?>
	<robot name="ground">
	<link name="ground">
	<visual>
	<geometry>
	<mesh filename="ground.obj" scale="2 2 0.1" />
	</geometry>
	<material name="white">
	<color rgba="1 1 1 1"/>
	</material>

erwincoumans / minitaur_gym_env.py

Created October 29, 2017 02:58

minitaur gym environment with bunny on its back

	"""This file implements the gym environment of minitaur.

	"""

	import os, inspect
	currentdir = os.path.dirname(os.path.abspath(inspect.getfile(inspect.currentframe())))
	parentdir = os.path.dirname(os.path.dirname(currentdir))
	os.sys.path.insert(0,parentdir)

erwincoumans / pybullet_physx

Last active December 19, 2020 05:16

	import pybullet as p
	import time

	usePhysX = True

	if usePhysX:
	p.connect(p.PhysX)
	p.loadPlugin("eglRendererPlugin")
	else:
	p.connect(p.GUI)

erwincoumans / read_scales.py

Created March 29, 2019 15:53

DYMO usb scale reading (multiple scales)


	import sys
	import usb.core
	VENDOR_ID = 0x0922
	PRODUCT_ID = 0x8003


	# find USB devices
	devices = list(usb.core.find(find_all=True, idVendor=VENDOR_ID,
	idProduct=PRODUCT_ID))

erwincoumans / BasicDemo.cpp

Created October 21, 2020 23:13

Kinematic btRigidBody example

	/*
	Bullet Continuous Collision Detection and Physics Library
	Copyright (c) 2015 Google Inc. http://bulletphysics.org

	This software is provided 'as-is', without any express or implied warranty.
	In no event will the authors be held liable for any damages arising from the use of this software.
	Permission is granted to anyone to use this software for any purpose,
	including commercial applications, and to alter it and redistribute it freely,
	subject to the following restrictions:

erwincoumans / render_tiled_cuda_torch_interop.py

Created August 25, 2022 21:40

opengl3 tiled rendering output to cuda / pytorch interop example

	#pycuda cuda interop inspired by
	#https://gist.github.com/victor-shepardson/5b3d3087dc2b4817b9bffdb8e87a57c4
	#and https://discuss.pytorch.org/t/create-edit-pytorch-tensor-using-opengl/42111/5
	#pip install pytinydiffsim, pycuda, numpy, matplotlib, PyQt5
	#visit https://pytorch.org/get-started/locally to install cuda-enabled pytorch
	#git clone https://github.com/erwincoumans/tiny-differentiable-simulator.git
	#cd tiny-differentiable-simulator/python/examples


	import pytinydiffsim as tds

erwincoumans / cube.py

Created October 11, 2022 01:01

Create 120k cubes in Blender 3.4 alpha: selection is broken (b key and select some region of cubes) and deletion (select all 'a', delete 'x') takes very long.

	#See Aras' post, https://twitter.com/aras_p/status/1579383862165405696
	import time
	import bpy
	print("hello world")
	mesh = bpy.data.meshes['Cube']
	start = time.time()
	for z in range (0,7,3):
	for x in range(-9,10):
	for y in range(-9,10):
	ob = bpy.data.objects.new("Gen", object_data=mesh)