So, yeah, silly question. :) Still haven't dived that deep into matrix
maths myself.
Thanks for the clarification Grahame! It's appreciated.
Mitch
On Tue, Aug 27, 2013 at 5:22 PM, Grahame Fuller
<grahame.ful...@autodesk.com <mailto:grahame.ful...@autodesk.com>> wrote:
T is not an exponent in that formula - rather MT is the transpose
of M.
gray
From: softimage-boun...@listproc.autodesk.com
<mailto:softimage-boun...@listproc.autodesk.com>
[mailto:softimage-boun...@listproc.autodesk.com
<mailto:softimage-boun...@listproc.autodesk.com>] On Behalf Of
Mitchell Lotierzo
Sent: Tuesday, August 27, 2013 6:15 PM
To: softimage@listproc.autodesk.com
<mailto:softimage@listproc.autodesk.com>
Subject: Re: SI Matrix3 and Maths
So out of curiosity (and pardon me if this is a silly question),
what exactly is the exponent of 'T' in that equation? I don't seem
to see a definition.
On Tue, Aug 27, 2013 at 3:38 PM, Matt Lind
<ml...@carbinestudios.com
<mailto:ml...@carbinestudios.com><mailto:ml...@carbinestudios.com
<mailto:ml...@carbinestudios.com>>> wrote:
Maggie hasn't been with Softimage for nearly 10 years. What's
everybody else's excuse?
Matt
-----Original Message-----
From: softimage-boun...@listproc.autodesk.com
<mailto:softimage-boun...@listproc.autodesk.com><mailto:softimage-boun...@listproc.autodesk.com
<mailto:softimage-boun...@listproc.autodesk.com>>
[mailto:softimage-boun...@listproc.autodesk.com
<mailto:softimage-boun...@listproc.autodesk.com><mailto:softimage-boun...@listproc.autodesk.com
<mailto:softimage-boun...@listproc.autodesk.com>>] On Behalf Of
Grahame Fuller
Sent: Tuesday, August 27, 2013 12:16 PM
To: softimage@listproc.autodesk.com
<mailto:softimage@listproc.autodesk.com><mailto:softimage@listproc.autodesk.com
<mailto:softimage@listproc.autodesk.com>>
Subject: RE: SI Matrix3 and Maths
Maggie.
gray
-----Original Message-----
From: softimage-boun...@listproc.autodesk.com
<mailto:softimage-boun...@listproc.autodesk.com><mailto:softimage-boun...@listproc.autodesk.com
<mailto:softimage-boun...@listproc.autodesk.com>>
[mailto:softimage-boun...@listproc.autodesk.com
<mailto:softimage-boun...@listproc.autodesk.com><mailto:softimage-boun...@listproc.autodesk.com
<mailto:softimage-boun...@listproc.autodesk.com>>] On Behalf Of
Matt Lind
Sent: Tuesday, August 27, 2013 3:04 PM
To: softimage@listproc.autodesk.com
<mailto:softimage@listproc.autodesk.com><mailto:softimage@listproc.autodesk.com
<mailto:softimage@listproc.autodesk.com>>
Subject: RE: SI Matrix3 and Maths
In a bit of irony, I actually don't know who was in charge of the
SDK guide.
Matt
-----Original Message-----
From: softimage-boun...@listproc.autodesk.com
<mailto:softimage-boun...@listproc.autodesk.com><mailto:softimage-boun...@listproc.autodesk.com
<mailto:softimage-boun...@listproc.autodesk.com>>
[mailto:softimage-boun...@listproc.autodesk.com
<mailto:softimage-boun...@listproc.autodesk.com><mailto:softimage-boun...@listproc.autodesk.com
<mailto:softimage-boun...@listproc.autodesk.com>>] On Behalf Of
Grahame Fuller
Sent: Tuesday, August 27, 2013 12:02 PM
To: softimage@listproc.autodesk.com
<mailto:softimage@listproc.autodesk.com><mailto:softimage@listproc.autodesk.com
<mailto:softimage@listproc.autodesk.com>>
Subject: RE: SI Matrix3 and Maths
It's been long enough that I can say this. Do you remember who was
in charge of the SDK guide? That's why.
gray
-----Original Message-----
From: softimage-boun...@listproc.autodesk.com
<mailto:softimage-boun...@listproc.autodesk.com><mailto:softimage-boun...@listproc.autodesk.com
<mailto:softimage-boun...@listproc.autodesk.com>>
[mailto:softimage-boun...@listproc.autodesk.com
<mailto:softimage-boun...@listproc.autodesk.com><mailto:softimage-boun...@listproc.autodesk.com
<mailto:softimage-boun...@listproc.autodesk.com>>] On Behalf Of
Eric Thivierge
Sent: Tuesday, August 27, 2013 2:57 PM
To: softimage@listproc.autodesk.com
<mailto:softimage@listproc.autodesk.com><mailto:softimage@listproc.autodesk.com
<mailto:softimage@listproc.autodesk.com>>
Subject: Re: SI Matrix3 and Maths
Formula? What you talkin' 'bout Willis?
Eric Thivierge
===============
Character TD / RnD
Hybride Technologies
On August-27-13 2:54:24 PM, Matt Lind wrote:
> Which begs the question - why is that formula in the user's
guide and
> not the sdk guide?
>
> I've wondered about that for years.
>
> Matt
>
> *From:*softimage-boun...@listproc.autodesk.com
<mailto:softimage-boun...@listproc.autodesk.com><mailto:softimage-boun...@listproc.autodesk.com
<mailto:softimage-boun...@listproc.autodesk.com>>
> [mailto:softimage-boun...@listproc.autodesk.com
<mailto:softimage-boun...@listproc.autodesk.com><mailto:softimage-boun...@listproc.autodesk.com
<mailto:softimage-boun...@listproc.autodesk.com>>] *On Behalf Of
> *Grahame Fuller
> *Sent:* Tuesday, August 27, 2013 11:52 AM
> *To:* softimage@listproc.autodesk.com
<mailto:softimage@listproc.autodesk.com><mailto:softimage@listproc.autodesk.com
<mailto:softimage@listproc.autodesk.com>>
> *Subject:* RE: SI Matrix3 and Maths
>
> Just to clarify, that's the order of the matrices in the
> multiplication, which in a row-vector world corresponds to
performing
> the transformations interactively in the opposite order.
>
> If there's non-uniform scaling involved and hierarchical scaling is
> on, it's more complicated. For the gruesome details, scroll to the
> bottom of this page:
>
http://download.autodesk.com/global/docs/softimage2014/en_us/userguide/index.html?url=files/transforms_ScalingObjects.htm,topicNumber=d30e51306.
>
> If there's no non-uniform scaling then everything works out the same
> as for classic scaling.
>
> gray
>
> *From:*softimage-boun...@listproc.autodesk.com
<mailto:softimage-boun...@listproc.autodesk.com><mailto:softimage-boun...@listproc.autodesk.com
<mailto:softimage-boun...@listproc.autodesk.com>>
> <mailto:softimage-boun...@listproc.autodesk.com
<mailto:softimage-boun...@listproc.autodesk.com><mailto:softimage-boun...@listproc.autodesk.com
<mailto:softimage-boun...@listproc.autodesk.com>>>
> [mailto:softimage-boun...@listproc.autodesk.com
<mailto:softimage-boun...@listproc.autodesk.com><mailto:softimage-boun...@listproc.autodesk.com
<mailto:softimage-boun...@listproc.autodesk.com>>] *On Behalf Of
*Daniel
> Brassard
> *Sent:* Tuesday, August 27, 2013 2:29 PM
> *To:* softimage@listproc.autodesk.com
<mailto:softimage@listproc.autodesk.com><mailto:softimage@listproc.autodesk.com
<mailto:softimage@listproc.autodesk.com>>
> <mailto:softimage@listproc.autodesk.com
<mailto:softimage@listproc.autodesk.com><mailto:softimage@listproc.autodesk.com
<mailto:softimage@listproc.autodesk.com>>>
> *Subject:* Re: SI Matrix3 and Maths
>
> BTW, the order of operation on the matrices is important. For
> Softimage you scale, rotate then translate (SRT like the order
in the
> MCP, easy way to remember). Any other way and you will have
> unpredictable results.
>
> On Tue, Aug 27, 2013 at 2:12 PM, Daniel Brassard
> <dbrassar...@gmail.com
<mailto:dbrassar...@gmail.com><mailto:dbrassar...@gmail.com
<mailto:dbrassar...@gmail.com>> <mailto:dbrassar...@gmail.com
<mailto:dbrassar...@gmail.com><mailto:dbrassar...@gmail.com
<mailto:dbrassar...@gmail.com>>>> wrote:
>
> A pretty good explanation of row vector and transform Matrix here.
>
>
http://msdn.microsoft.com/en-us/library/windows/desktop/bb206269(v=vs.
> 85).aspx
>
> On Tue, Aug 27, 2013 at 1:39 PM, Grahame Fuller
> <grahame.ful...@autodesk.com
<mailto:grahame.ful...@autodesk.com><mailto:grahame.ful...@autodesk.com
<mailto:grahame.ful...@autodesk.com>>
<mailto:grahame.ful...@autodesk.com
<mailto:grahame.ful...@autodesk.com><mailto:grahame.ful...@autodesk.com
<mailto:grahame.ful...@autodesk.com>>>> wrote:
>
> I'm pretty sure it's the row versus column vector issue. In a
> nutshell, most of the CG world, including Softimage, treats
vectors as
> rows, i.e., 1x3 matrices. The rest of the world, including most
> references you'll find for math, physics, robotics, etc., treats
> vectors as columns, i.e., 3x1 matrices.
>
> In a row-vector world, you construct your transform by inserting
your
> X,Y,Z basis vectors into a matrix as rows. The order of
multiplication
> for transforms is Mchild x Mparent, and when multiplying a
vector and
> matrix the vector goes on the left and the matrix on the right.
>
> In a column-vector world, it's the opposite. You construct your
> transform by inserting your X,Y,Z basis vectors into a matrix as
> columns. The order of multiplication for transforms is Mparent x
> Mchild, and when multiplying a vector and matrix the vector goes on
> the right and the matrix on the left.
>
> In particular, note that the row-vector transform is transposed
> (mirrored across the diagonal) from the column-vector transform.
So if
> the formulas for your individual rotation matrices matX, matY, and
> matZ came from a reference that uses column-vectors, you need to
> transpose the matrices.
>
> To calculate the various rotation orders, you just need to multiply
> the matrices in different orders. In a row-vector world, you use
> reverse order, for example, if you want XYZ order then you calculate
> matZ x matY x matX. Luckily matrix multiplication is the same in
both
> row-vector and column-vector worlds, so you can save some processor
> time by figuring it out long-hand and stuffing the final values into
> the full transform matrix directly, like in the code sample you
> showed, but of course it's easy to make a typo or other mistake.
>
> gray
>
> From: softimage-boun...@listproc.autodesk.com
<mailto:softimage-boun...@listproc.autodesk.com><mailto:softimage-boun...@listproc.autodesk.com
<mailto:softimage-boun...@listproc.autodesk.com>>
> <mailto:softimage-boun...@listproc.autodesk.com
<mailto:softimage-boun...@listproc.autodesk.com><mailto:softimage-boun...@listproc.autodesk.com
<mailto:softimage-boun...@listproc.autodesk.com>>>
> [mailto:softimage-boun...@listproc.autodesk.com
<mailto:softimage-boun...@listproc.autodesk.com><mailto:softimage-boun...@listproc.autodesk.com
<mailto:softimage-boun...@listproc.autodesk.com>>
> <mailto:softimage-boun...@listproc.autodesk.com
<mailto:softimage-boun...@listproc.autodesk.com><mailto:softimage-boun...@listproc.autodesk.com
<mailto:softimage-boun...@listproc.autodesk.com>>>] On Behalf Of Eric
> Thivierge
> Sent: Monday, August 26, 2013 8:21 PM
> To: softimage@listproc.autodesk.com
<mailto:softimage@listproc.autodesk.com><mailto:softimage@listproc.autodesk.com
<mailto:softimage@listproc.autodesk.com>>
> <mailto:softimage@listproc.autodesk.com
<mailto:softimage@listproc.autodesk.com><mailto:softimage@listproc.autodesk.com
<mailto:softimage@listproc.autodesk.com>>>
> Subject: Re: SI Matrix3 and Maths
>
> Thanks Raf I saw that today. It's a problem somewhere with my matrix
> multiplication I think. Tried a bunch of different combos but I'm
> thinking it's what Matt touched on either the row / column
mixing or a
> mistake in the shorthand somewhere.
>
> --------------------------------------------
> Eric Thivierge
> http://www.ethivierge.com
>
> On Mon, Aug 26, 2013 at 8:15 PM, Raffaele Fragapane
> <raffsxsil...@googlemail.com
<mailto:raffsxsil...@googlemail.com><mailto:raffsxsil...@googlemail.com
<mailto:raffsxsil...@googlemail.com>>
> <mailto:raffsxsil...@googlemail.com
<mailto:raffsxsil...@googlemail.com><mailto:raffsxsil...@googlemail.com
<mailto:raffsxsil...@googlemail.com>>><mailto:raffsxsil...@googlemail.co
<mailto:raffsxsil...@googlemail.co><mailto:raffsxsil...@googlemail.co
<mailto:raffsxsil...@googlemail.co>>
> m <mailto:raffsxsil...@googlemail.com
<mailto:raffsxsil...@googlemail.com><mailto:raffsxsil...@googlemail.com
<mailto:raffsxsil...@googlemail.com>>>>>
> wrote:
> The rotation order matters.
> It's as simple as each rotation pushing a gimbal along by a linear
> distance of trigonometric functions of that angle in turns, in the
> rotation order... order.
> Wikipedia has the matricial forms:
> http://en.wikipedia.org/wiki/Rotation_matrix#Basic_rotations
> What's not working from that? Or if you haven't looked at it,
shame on
> you!
>
