 | | Re: Inverse matrix?
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| (...) I mean swap the OFF-diagonals, leave the diagonals as is. (...) (20 years ago, 7-Apr-07, to lugnet.cad.ray, lugnet.cad)
| | |  | | Re: how does a line ends?
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| (...) Interesting. I looked at the C runtime library sources that came with MSVC++ 6.0. The fgets() function there is definitely a little different than either yours or the one ROSCO linked. It does have a couple calls for thread safety, but (...) (20 years ago, 7-Apr-07, to lugnet.cad, FTX)
| | |  | | Re: Inverse matrix?
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| (...) Just take the transpose of the 3x3 world rotation matrix and it should work as the inverse. Transpose means swap diagonals M[1,2] <=> M[2,1] etc. If this doesn't work I've misunderstood you. Tim (20 years ago, 7-Apr-07, to lugnet.cad.ray, lugnet.cad)
| | |  | | Re: Inverse matrix?
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| (...) Hehehe, cool, I'll try that. Thanks! James (20 years ago, 7-Apr-07, to lugnet.cad.ray, lugnet.cad)
| | |  | | Re: Inverse matrix?
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| Clarification! .... snip (...) I am using additional points to specify the location of feet. Combined with the model location, I have 3 points for the hip and feet. [now the following paragraph should make more sense] (...) (20 years ago, 7-Apr-07, to lugnet.cad.ray, lugnet.cad)
| | |  | | Re: Inverse matrix?
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| (...) Arg. I thought this was going to be easy. I liked this part of the wikipedia article: "In practice, inverting a matrix is rarely required. Most of the time, one is really after the solution of a particular system of linear equations." Hm. I (...) (20 years ago, 7-Apr-07, to lugnet.cad.ray, lugnet.cad)
| | |  | | Re: how does a line ends?
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| (...) Thanks, ROSCO. I took that code and modified it to use char instead of _TCHAR, and got timings of 720-750ms, compared to the 750-780ms I got with my original one. I then modified it to support CR and LF interchangeably, and got back to the (...) (20 years ago, 7-Apr-07, to lugnet.cad, FTX)
| | |  | | Re: Inverse matrix?
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| (...) I just realised something... do you want a general inverse or a specific inverse? Some inversions are simple eg. a pure rotation can be inverted by taking its transpose and reflections are their own inverses. Tim (20 years ago, 7-Apr-07, to lugnet.cad.ray, lugnet.cad)
| | |  | | Re: how does a line ends?
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| (...) Just as a proof of the value of disk caching, loading the same model using the system fgets after a fresh reboot, the same loading portion took 3300ms. Also, I switched the feof calls out for a check of the value against EOF just to see if it (...) (20 years ago, 7-Apr-07, to lugnet.cad, FTX)
| | |  | | Re: how does a line ends?
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| (...) (URL) Google to the rescue>. ROSCO (20 years ago, 7-Apr-07, to lugnet.cad, FTX)
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