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.B "\-s sf .." |
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][ |
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.B "\-c ce .." |
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+ |
][ |
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+ |
.B "\-rf|\-rb" |
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] |
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.B m1 |
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[ |
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< |
.B "+*/" |
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> |
.B ".+*/" |
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] |
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.B ".." |
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.SH DESCRIPTION |
| 49 |
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using quotes and a beginning exclamation point ('!'). |
| 50 |
|
.PP |
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Two special cases are handled for component matrices that are either |
| 52 |
< |
XML files containing BTDF data, or Radiance picture files. |
| 53 |
< |
In the first case, a BSDF library is used to load and interpret the |
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< |
transmission matrix. |
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> |
XML files containing BSDF data, or Radiance picture files. |
| 53 |
> |
In the first case, the BSDF library loads and interprets the |
| 54 |
> |
transmission matrix by default. |
| 55 |
> |
Alternatively, the front (normal-side) reflectance is selected if the |
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> |
.I \-rf |
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> |
option precedes the file name, or the backside reflectance if |
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> |
.I \-rb |
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> |
is specified. |
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(XML files cannot be read from the standard input or from a command.)\0 |
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In the second case, the RGBE or XYZE values are loaded in a 3-component |
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matrix where the number of columns match the X-dimension of the picture, and |
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the number of rows match the Y-dimension. |
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The picture must be in standard pixel ordering, and the first row |
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is at the top with the first column on the left. |
| 66 |
+ |
Any exposure changes that were applied to the pictures before |
| 67 |
+ |
.I rmtxop |
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+ |
will be undone, similar to the |
| 69 |
+ |
.I pcomb(1) |
| 70 |
+ |
.I \-o |
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+ |
option. |
| 72 |
|
.PP |
| 73 |
|
Before each file, the |
| 74 |
|
.I \-t |
| 109 |
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to the same input matrix. |
| 110 |
|
.PP |
| 111 |
|
If present, the second and subsequent matrices on the command |
| 112 |
< |
line are concatenated to the result unless separated by a plus ('+'), |
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> |
line are concatenated together, unless separated by a plus ('+'), |
| 113 |
|
asterisk ('*'), or forward slash ('/') symbol, |
| 114 |
< |
in which case the matrix elements are added, multiplied, or divided together, |
| 115 |
< |
respectively. |
| 116 |
< |
(Note that the asterisk must be quoted or escaped in most shells.)\0 |
| 114 |
> |
in which case the individual matrix elements are added, |
| 115 |
> |
multiplied, or divided, respectively. |
| 116 |
> |
The concatenation operator ('.') is the default and need not be specified. |
| 117 |
> |
Note also that the asterisk must be quoted or escaped in most shells. |
| 118 |
|
In the case of addition, the two matrices involved must have the same number |
| 119 |
|
of components. |
| 120 |
+ |
If subtraction is desired, use addition ('+') with a scaling parameter of -1 |
| 121 |
+ |
for the second matrix (the |
| 122 |
+ |
.I \-s |
| 123 |
+ |
option). |
| 124 |
|
For element-wise multiplication and division, the second matrix is |
| 125 |
< |
permitted instead to have a single component per element, which will be |
| 125 |
> |
permitted to have a single component per element, which will be |
| 126 |
|
applied equally to all components of the first matrix. |
| 127 |
|
If element-wise division is specified, any zero elements in the second |
| 128 |
|
matrix will result in a warning and the corresponding component(s) in the |
| 129 |
|
first matrix will be set to zero. |
| 130 |
|
.PP |
| 131 |
< |
The number of components in the new matrix after applying any |
| 131 |
> |
Evaluation proceeds from left to right, and all operations have |
| 132 |
> |
the same precedence. |
| 133 |
> |
If a different evaluation order is desired, pipe the result of one |
| 134 |
> |
.I rmtxop |
| 135 |
> |
command into another, as shown in one of the examples below. |
| 136 |
> |
.PP |
| 137 |
> |
The number of components in the next matrix after applying any |
| 138 |
|
.I -c |
| 139 |
|
transform must agree with the prior result. |
| 140 |
|
For concatenation (matrix multiplication), the number of columns |
| 141 |
< |
in the prior result must equal the number of rows in the new matrix, and |
| 141 |
> |
in the prior result must equal the number of rows in the next matrix, and |
| 142 |
|
the result will have the number of rows of the previous and the number |
| 143 |
< |
of columns of the new matrix. |
| 143 |
> |
of columns of the next matrix. |
| 144 |
|
In the case of addition, multiplication, and division, |
| 145 |
|
the number of rows and columns of the prior result and the |
| 146 |
< |
new matrix must match, and will not be changed by the operation. |
| 146 |
> |
next matrix must match, and will not be changed by the operation. |
| 147 |
|
.PP |
| 148 |
+ |
A final transpose or scaling/transform operation may be applied to |
| 149 |
+ |
the results by appending the |
| 150 |
+ |
.I \-t |
| 151 |
+ |
and |
| 152 |
+ |
.I \-s |
| 153 |
+ |
or |
| 154 |
+ |
.I \-c |
| 155 |
+ |
options after the last matrix on the command line. |
| 156 |
+ |
.PP |
| 157 |
|
Results are sent to the standard output. |
| 158 |
|
By default, the values will be written in the lowest resolution format |
| 159 |
|
among the inputs, but the |
| 179 |
|
.IP "" .2i |
| 180 |
|
rmtxop -fc blinds.xml > blinds.hdr |
| 181 |
|
.PP |
| 182 |
+ |
To extract the luminance values from a picture as an ASCII matrix: |
| 183 |
+ |
.IP "" .2i |
| 184 |
+ |
rmtxop -fa -c .265 .670 .065 image.hdr > image_lum.mtx |
| 185 |
+ |
.PP |
| 186 |
|
To scale a matrix by 4 and add it to the transpose of another matrix: |
| 187 |
|
.IP "" .2i |
| 188 |
< |
rmtxop -s 4 left.mtx + -t right.mtx > result.mtx |
| 188 |
> |
rmtxop -s 4 first.mtx + -t second.mtx > result.mtx |
| 189 |
|
.PP |
| 190 |
+ |
To multiply elements of two matrices, then concatenate with a third, |
| 191 |
+ |
applying a final transpose to the result: |
| 192 |
+ |
.IP "" .2i |
| 193 |
+ |
rmtxop first.mtx \\* second.mtx . third.mtx -t > result.mtx |
| 194 |
+ |
.PP |
| 195 |
+ |
To left-multiply the element-wise division of two matrices: |
| 196 |
+ |
.IP "" .2i |
| 197 |
+ |
rmtxop -fd numerator.mtx / denominator.mtx | rmtxop left.mtx - > result.mtx |
| 198 |
+ |
.PP |
| 199 |
|
To send the elements of a binary matrix to |
| 200 |
|
.I rcalc(1) |
| 201 |
|
for further processing: |
| 202 |
|
.IP "" .2i |
| 203 |
|
rmtxop -fa orig.mtx | rcollate -ho -oc 1 | rcalc [operations] |
| 204 |
+ |
.SH NOTES |
| 205 |
+ |
Matrix concatenation is associative but not commutative, so order |
| 206 |
+ |
matters to the result. |
| 207 |
+ |
.I Rmtxop |
| 208 |
+ |
takes advantage of this associative property to concatenate |
| 209 |
+ |
from right to left when it reduces the number of basic operations. |
| 210 |
+ |
If the rightmost matrix is a column vector for example, it is |
| 211 |
+ |
much faster to concatenate from the right, and the result will |
| 212 |
+ |
be the same. |
| 213 |
+ |
Note that this only applies to concatenation; |
| 214 |
+ |
element-wise addition, multiplication, and division are always |
| 215 |
+ |
evaluated from left to right. |
| 216 |
|
.SH AUTHOR |
| 217 |
|
Greg Ward |
| 218 |
|
.SH "SEE ALSO" |
| 219 |
< |
cnt(1), getinfo(1), histo(1), neaten(1), rcalc(1), rcollate(1), |
| 220 |
< |
rcontrib(1), rfluxmtx(1), rlam(1), tabfunc(1), total(1), wrapBSDF(1) |
| 219 |
> |
cnt(1), getinfo(1), histo(1), neaten(1), pcomb(1), rcalc(1), |
| 220 |
> |
rcollate(1), rcontrib(1), rfluxmtx(1), rlam(1), |
| 221 |
> |
rsplit(1), tabfunc(1), total(1), wrapBSDF(1) |
