From mboxrd@z Thu Jan 1 00:00:00 1970 From: "=?ISO-8859-1?Q?STenyaK_(Bruno_Gonz=E1lez)?=" Subject: Re: FF layer restrictions [Was: [PATCH 1/1] Input: add sensable phantom driver] Date: Wed, 14 Mar 2007 20:18:54 +0100 Message-ID: <8e4ff20a0703141218r3add7923n74470b5e16f58c5c@mail.gmail.com> References: <2460126662758025813@fi.muni.cz> <4af2d03a0703130919nb4893b1ja9ec795dcf4bf53c@mail.gmail.com> <38b3b7c0703131450v2646e63fj2be4b9dda7f928c0@mail.gmail.com> <45F722CE.9000602@gmail.com> <45F82626.8000108@gmail.com> <45F83930.4060401@gmail.com> <8e4ff20a0703141147n4b690ab8g4cc8138d1ecc94e1@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Content-Disposition: inline Sender: owner-linux-input@atrey.karlin.mff.cuni.cz List-Help: List-Owner: List-Post: List-Unsubscribe: To: Dmitry Torokhov Cc: Anssi Hannula , Jiri Slaby , johann deneux , Linux kernel mailing list , linux-input@atrey.karlin.mff.cuni.cz List-Id: linux-input@vger.kernel.org On 3/14/07, Dmitry Torokhov wrote: > > I have a question: if the force is to be 3D, why only 3 possible values? > > What would they be, 3 torques or 3 forces? In the case of car sims (ff > > steering wheels), only one axis of torque is usually used (except for 6 dof > > platforms, as mentioned). > > > > I wonder if we could somehow extend or augment FF envelope se we could > specify a plane for the effect.. Then a vector could be represented by > a sum 3 constant effects in 3 separate planes and we could also use > spring and other effects as well. Ideally, afaik we should use: -3 values for translation force (linear force): x,y,z components of the force vector. -4 values for rotation force (torque): x,y,z,w components of the quaternion. You can also use euler angles (and i think there are another one or two notations), which is just 3 values, but i'm not sure it will be a correct decision (due to the gimbal lock problem, which may or may not be present in ff devices, dunno). -- Saludos, STenyaK _______________________________________________ Site: http://1ksurvivor.homeip.net <1kSurvivor> http://motorsport-sim.org http://kwh.iespana.es http://emuletutorial.info ICQ: 153709484 Mail: stenyak AT gmail DOT com