From 8ee775877398b2cc08041c8531716f3b4a6bb560 Mon Sep 17 00:00:00 2001 From: Ian Chen Date: Thu, 16 Jan 2025 11:12:22 -0800 Subject: [PATCH] Update Migration.md Co-authored-by: Steve Peters Signed-off-by: Ian Chen --- Migration.md | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/Migration.md b/Migration.md index eb7aa1ef4..5370703c6 100644 --- a/Migration.md +++ b/Migration.md @@ -15,14 +15,16 @@ but with improved human-readability.. ## libsdformat 15.1.1 to 15.2.0 -1. Auto-inertia computation now takes into account the mass if specified. -Previously when auto-inertia is set to true, mass is ignored and the inertia -matrix is computed based on the collision densities. The new behavior is that -if mass is specified, the inertial values will be computed to preserve the -specified mass. The is done by first resolving the inertia from all -collisions using density as usual, it is then normalized to get unit inertia, -and finally the unit inertia is scaled so that the resulting mass matches the -specified mass. +1. Inertial parameters can now be automatically calculated with a specified +mass. Previously when the `//inertial/@auto` attribute is set to true, the +`//inertial/mass` value is ignored and the mass, center of mass location, and +inertia matrix are computed based on the collision geometries and densities. +The new behavior is that if `//inertial/mass` is specified, the inertial values +will be computed to preserve the specified mass. This is done by first +calculating inertial parameters from all collisions using density as usual, +calculating the ratio between user-specified mass and the auto-computed mass, +and rescaling the computed mass and moment of inertia by that mass ratio so +that the resulting mass matches the specified mass. ## libsdformat 14.x to 15.x