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When started from a shell command line, the mental ray rendering
software accepts a large number of options. Most of these correspond to
similar commands or camera or options statements in the scene file.
When an option is given on the command line, it overrides the
corresponding command or statement in the scene file, which in turn
overrides the defaults. The defaults for certain options given in the
option list below apply only if the corresponding command or statement
is not present in the scene file.
mental ray is started as
ray [options] [scenefile]
If no scene file is given, the scene is read from standard input.
Scene file names normally end in .mi. If the extension is missing
mental ray will read the name as specified, and if this fails, retry
with .mi added.
Options can be abbreviated as long as the given substring is
unambiguous. mental ray checks for ambiguities and prints an error
message listing the choices. For example, -resolution can be
abbreviated as -res. For frequently-used options such as
-verbose and -filename, short forms are available.
The page numbers on the right side refer to the relevant chapters
in the main part of this book. The available options are:
- -acceleration bsp|grid|raycl
Selects the binary space partitioning ( BSP), voxel
grid, or ray classification2.1 rendering
algorithm. The default is BSP.
- -approx [options] -3.1
mental ray 3.1.2 and later allow specifying override
approximations on the command line. Override approximations
override any object approximations in the scene file. They are
primarily useful for fast preview rendering, where approximation
accuracy is not required. The following options can be
specified:
view |
view-dependent approximation |
fine |
fine approximation with microtriangles |
sharp |
faceted, useful for fine displacement |
parametric U V |
rectangular grid of U . V . 2 triangles |
regular U V |
rectangular grid that spans patches |
length L |
triangle edge length less than D |
distance D |
distance from true surface less than D |
angle A |
angle between neighboring triangles less
than |
|
A degrees |
any |
it is sufficient if any of length,
distance, and |
|
angle is satisfied |
min max |
subdivide at least min and at most
max times, |
|
default 0 5 |
- Except for any, which must be spelled out, all options
can be abbreviated by their first letter. If no options are
specified (-approx -), parametric 0 0 is used, which
produces a very fast low-quality approximation. See the scene
description chapter for detailed information on approximations.
- -approx_displace [options] -3.1
This option is similar to -approx and accepts the same
options, but sets the override approximation for displacement.
If no options are given, it defaults to parametric 0 0, which
is so low that most displacements turn into a vaguely bumpy
surface. High-quality displacement requires an approximation
like -approx fine view length 0.25 0 7 -.
- -aperture aperture
The aperture is the width of the viewing plane. The
height of the viewing plane is aperture divided by
aspect.
- -aspect aspect
This is the aspect ratio of the camera. The default is
1.33. In camera space, aperture is the width of the
viewing plane, and aperture divided by aspect
is the height. The viewing plane is divided into pixels as
specified by the resolution viewdef, so the aspect
will result in nonsquare pixels if it is not equal to the X
resolution divided by the Y resolution.
- -bsp_depth depth
The maximum number of levels in the BSP tree. This option
is used only if binary space partitioning is enabled. Larger
tree depths reduce rendering time but increase memory consumption,
and also slightly increase preprocessing time. The default is 40.
- -bsp_memory memory
The maximum memory in megabytes used in BSP preprocessing. A
value of zero indicates that there is no limit on the memory
consumption; this is the default.
- -bsp_size size
The maximum number of primitives in a leaf of the BSP tree.
Larger leaves will be subdivided unless the bsp_depth is reached.
This option is used only if binary space partitioning is enabled.
Larger leaf sizes reduce memory consumption but increase rendering
time. The default is 10.
- -bsp_shadow on|off3.1
mental ray 3.1.2 and later support a separate shadow BSP tree
that accelerates raytraced shadows. It can greatly improve speed
if shadows are cast by simplified shadow-only objects because it
is no longer necessary to populate the master BSP tree with large
hero objects. This mode is off by default.
- -caustic on|off
Enable or disable the generation of caustics in an
appropriately defined scene. The default is off.
- -caustic_accuracy nphotons [radius]
The number of photons used to estimate caustics during
rendering and the maximum radius to be used when picking up the
photons. The number of photons may be set to 0, which means
that all photons within the given radius are used. The defaults
are 100 and a scene-size dependent radius.
- -clip hither yon
The hither (near) and yon (far) planes are planes
parallel to the viewing plane that delimit the rendered
scene. Points outside the space between the
hither and yon planes will not be rendered.
The defaults are 0.001 and 1000000.0.
- -code "filename" ... -
The named filename is interpreted as a C source file
(ending with the extension ``.c'') and compiled and linked into
mental ray.
- -colorclip rgb|alpha|raw
This option controls the rules used to clip
an RGBA color before quantization to an 8-bit or 16-bit frame
buffer6.1. The rgb mode states that RGB are first
to be clipped to the range [0, 1] before A is clipped to
[max(R, G, B), 1]. This is the default mode. The alpha
mode lets A first be clipped to [0, 1] before RGB is clipped
to [0, A]. Both of these modes ensure that all channels are
within [0, 1] and that A is no less than any of R, G, and B,
which is is the valid domain of premultiplied colors. The
third mode, raw, ignores all requirements, and clips
both A and RGB to [0, 1]. This is useful to make mental ray
modify output colors as little as possible. Because the color
output may be invalid, the raw mode overrides the premultiply off option if present.
Desaturation is always applied if enabled.
- -contrast r g b [a]
The contrast controls oversampling. If neighboring
samples differ by more than the color r, g, b, a,
oversampling is done as specified by the sampling
options. The default is 0.1 0.1 0.1 0.1. If
missing, the default for a is the average of r,
g, and b.
- -c_compiler "filename"
If this option is given, the standard C compiler "cc" is
replaced with filename.
- -c_flags "options"
The options string replaces the standard options given to
the C compiler. The defaults depend on the machine type. If
the options begin with two plus signs6.2, such as "++ -I.", it is inserted into the default options instead of
replacing them.
- -c_linker "filename"
If this option is given, the standard linker "ld" is
replaced with filename.
- -desaturate on|off
If a rendered sample returns an RGBA color whose components are
outside the legal range, mental ray will clip the color into
this legal range. This option determines how the clipping of R,
G, and B is performed. If desaturation is turned off, which
is the default, the components are clipped individually. If
turned on, then if any of R, G, and B exceed the allowed range,
the color is shifted towards the grayscale axis of the color
cube in order to try to maintain the perceived brightness of
that color, effectively bleaching out the color. The valid
range of RGBA is controlled by the colorclip option.
- -diagnostic bsp depth|size
This diagnostic mode6.3 can be used to visualize
the parameters for BSP tree parameters (see -bsp
depth and -bsp size options), to find the reason for
unexpected large depths or sizes reported after rendering.
- -diagnostic grid off|object|world|camera size
This diagnostic mode6.4 is intended for scene
debugging. Unless set to off, it draws a colored grid on
all objects in the scene that shows object,
world, or camera space coordinates. Steps
on the X, Y, and Z axes are shown with red, green, and blue
grid lines, respectively. The distance between grid lines is
size units. This is useful to estimate the size and
distances between objects in mental ray, or to visualize object
space coordinates. The off argument disables the grid.
The default is off.
- -diagnostic photon off|density|irradiance max
When rendering caustics or global illumination, this
option disables all material shaders in the scene and produces
a false-color rendering of photon density, or the average of
the red, green, and blue irradiance components. Photon density
is the number of photons per unit surface area. max is the
density (or irradiance) that is assigned to 100%, or red. The
colors are, from 0% to 100%: Blue, cyan, green, yellow, and
red. Higher values fade to white. max can be given as zero
in which case the appropriate maximum is automatically found.
This is done after the whole image has been rendered. This
mode is useful when tuning the number of photons in a photonmap
and setting the various _accuracy options, since the
density (or irradiance) is estimated using those settings. The
default is off.
- -diagnostic samples
Switch to sampling visualization mode and create grayscale
images representing sampling densities instead of color images.
A black pixel has had no samples, whereas a white pixel has had
the maximum amount as specified by the -samples option. In
addition, a red grid shows task rectangle boundaries.
- -diagnostic finalgather3.1
This mode shows final gathering points, as green dots for initial
raster-space final gathering points and red dots for render-time
final gathering points.
- -displace on|off
Ignore all displacement shaders if set to off. The
default is on.
- -dither on|off
Dithering dithering mitigates 8-bit and 16-bit color
quantization errors by introducing noise into the pixel such
that the round-off errors are randomly distributed. The default
is off.
- -echo "filename"
[ascii]
[source]
[approx]
[norendercommand]
[textures]
[omit "S"]
[norecurse "S"]
-
Echo the current scene to the file filename. The options
specify the format of the echoed file. Allowed options are:
- ascii uses ascii format for the vectors (default is binary),
- source prefers source geometry over triangles if available
(default),
- approx prefers triangles over source geometry if available,
- norendercommand disables the echo of the render command,
- textures includes texture pixel data verbatim.
- omit specifies that certain types of elements, specified
by S, should be omitted from the output. It is supported
by mental ray 3.0 only. Note that both omit and norecurse will produce incomplete and nonrenderable scene files.
These options are useful for extracting subsets of a scene.
- norecurse specifies that references of certain types of
elements specified by S should be omitted from the output.
It is supported by mental ray 3.0 only. For example, if S contains icil, instances of cameras and lights would be
echoed (unless disabled by omit), but the instanced camera
or light would not be echoed first. The S strings of the
omit and norecurse attributes are sequences of the
following codes:
code |
element |
affected statement |
g |
instance group |
instgroup |
o |
geometric object |
object |
c |
camera |
camera |
l |
light source |
light |
m |
material |
material |
t |
texture |
texture |
p |
option block |
options |
s |
named shader |
shader |
d |
declaration |
declare |
u |
user data |
data |
ig |
instance of an instance group |
instance |
io |
instance of an object |
instance |
ic |
instance of a camera |
instance |
il |
instance of a light |
instance |
is |
instance of a geometry shader |
instance |
- Note that triangle echos have displacement mapping already
applied to the triangles, but the displacement shaders are not
removed from the materials so the echoed file will get
displaced twice when rendered. The echo option must be
terminated with a double minus.
- -face front|back|both
The front side of a geometric object in the scene is
defined to be the side its normal vector points away from. By
specifying that only front-facing triangles are
to be rendered, speed can be improved because fewer triangles
need to be tested for a ray. The default is face both.
- -file_name "filename"
Overrides the file name given by the first file output
statement in the camera definition in the scene file. The full
file or path name must be given, including extension if
desired.
- -file_type "format"
Overrides the file format given by the first file output
statement in the camera definition in the scene file. File
formats include "pic" for Softimage image files, "rla" for Wavefront RLA files, and "ps" for PostScript
files if contour mode is enabled.
- -filter box|triangle|gauss|mitchell|lanczos width [height]
This option specifies how multiple samples in recursive
sampling mode are to be combined. The filter defaults to a box
filter of width and height 1. The filter size can also be
specified, in pixel units. Good filter sizes are 1.0 for box, 2.0 for triangle, 3.0 for gauss, and 4.0 for
mitchell and lanczos6.5.
In mental ray 2.0, this option requires a sampling density of
at least 1 1; in mental ray 2.1 and later the sampling
density must be at least -1 0.
- -finalgather on|off|fastlookup
Enables or disables final gathering6.6. It is disabled by default.
Final gathering is a rendering technique used for computing
indirect illumination with a one-generation raytracing step.
mental ray 3.0 adds a third choice, fastlookup, that
enables final gathering and also arranges for irradiance to
be stored in the photon map. This slows down photon
tracing but greatly accelerates final gathering.
- -finalgather_accuracy [ view ] nrays_int [maxdist [mindist]]
nrays is the number of rays cast in a final gathering step
during rendering. The default is 1000. maxdist is the
maximum distance within which a final gather result can be
reused. The default is scene dependent. mindist is the
minimum distance within which final gather results must be
reused. The default is scene dependent. Both distances are
specified in world space units, or raster space units if view3.x is specified.
- -focal distance|infinity
The focal distance is set to distance. The focal
distance is the distance from the camera to the viewing
plane. The viewing plane is the plane in front of the camera
that the rendered scene is projected onto; its edges correspond
to the edges of the rendered image. If infinity is used
in place of the distance, an orthographic
view is rendered.
- -gamma gamma_factor
Gamma correction can be applied to rendered color pixels to
compensate for output devices with a nonlinear color response.
All R, G, B, and alpha component values are raised to
gamma_factor. The default gamma factor is 1.0, which turns
gamma correction off.
- -geometry on|off
Ignore all geometry shaders if set to off. The
default is on.
- -globillum on|off
Enable or disable the computation of global
illumination6.7. The default is off. To actually compute
global illumination, lights must have an energy, and materials
must have photon shaders.
- -globillum_accuracy nphotons_int [radius]
The number of photons used to estimate global
illumination during rendering and the maximum radius to be
used when reading photons during rendering. The defaults
number of photons is 500. If nphotons is set to 0, all
photons within the given radius are used. The default radius is
scene size dependent.
- -grid_depth depthint3.1
If the hierarchical grid algorithm3.1 is used, this
option sets the number of recursion levels. If a voxel of a
grid contains too much detail, it is subdivided by a subgrid
for that voxel, which adds another level.
- -grid_resolution xres
[yres
zres
3.1
If the hierarchical grid algorithm3.1 is used, this
option sets the number of grid voxels in the X, Y, and Z
dimensions. If only one number is given, it is used for all
three dimensions. The default is 0 0 0, which selects a
default computed at runtime.
- -grid_size factor
If the static grid algorithm2.1 is used, factor is a
correction factor for mental ray's internal guess for the grid
resolution, so that numbers greater than 1.0 increase the
number of voxels in each dimension and numbers less than 1.0
decrease it.
- -grid_size sizeint3.1
If the hierarchical grid algorithm3.1 is used, this
option sets the maximum number of triangles in a grid voxel. If
there are more, and the grid depth permits it, the voxel is
subdivided into a subgrid.
- -help
Print a summary of all options with their allowed parameters,
and terminate.
- -hosts "hostname[:portnumber] [
remote parameters]" ... -
The machine list overrides the machine list taken from the .rayhosts file, if present. One slave is started on each
machine specified. Machine names must be given as expected by
the local name resolving method (such as /etc/hosts) or
as a numeric internet address (nnn.nnn.nnn.nnn).
- -I "path1:path2:..."
Overrides the path used to resolve $include statements
in the .mi scene file. The default path contains the
directories ., {_MI_REG_INCLUDE} (see
page
), /usr/local/mi/rayinc, /usr/include, and /usr/include/mi. Note that only one
-I option can be specified. It may contain a
colon-separated ( Unix only) or semicolon-separated
( Unix and Windows NT) list of directory paths that are
tried in sequence if a $include statement using angle
brackets is used in the .mi scene file. Paths introduced with
an exclamation point are special; they are applied to quoted
$include paths too, and substitute the entire directory
path. This can be used to force mental ray to use a specified
path regardless of the path specified in the $include
statement, for example because that path points to an obsolete
(1.9) version of a declaration file. For example, -I
/a:/b:!/new tries to find a path <x/y/z> first as /a/x/y/z, then /b/x/y/z, then /new/z.
- -imgpipe fd
Normally mental ray prints connection information into the
output image file that let programs like imf_disp
connect and display images while being rendered. If -imgpipe is used, the relevant information is printed to the
given file descriptor fd instead. This can be used for
command lines such as ``ray -imgpipe 1 scene.mi |
imf_disp -''. The imf_disp program is a viewer
provided by mental images that supports image piping.
- -jitter jitter
The jittering factor introduces systematic variations into
sample locations if jitter is set to 1.0. Jittering is turned
off by default, or by specifying a jitter of 0.0.
- -jobmemory physical [ virtual ]
The physical argument specifies the size of mental ray 3.x's
cache memory, in megabytes. The default is unlimited for mental
ray 3.0 and 512 for mental ray 3.1. (mental ray 3.1 supports
fine microtriangle tessellation which depend on the ability to
flush obsolete triangles from the cache.) The virtual number
of megabytes limits the amount of virtual address space available
for memory mapping, mostly for memory mapped textures; the
default is 1024 (1 GB) on 32-bit machines and 0 (unlimited) on
64-bit machines.
- -L "path1:path2:..."
This is an abbreviation for -ld_path.
- -ld_libs "libraries"
The libraries string replaces the standard library options
given to the linker. The defaults depend on
the machine used, typically "-lm -lc". Linker options are
machine dependent and operating system dependent and cannot be
changed.
- -ld_path "path1:path2:..."
Supply a list of library search paths that mental ray
searches for shader libraries containing
shader code. The paths given here precede those that can be
given by the environment variable MI_LIBRARY_PATH
and the built-in search path (consisting of the directories
{_MI_REG_LIBRARY}, /usr/local/mi/lib, and .; see page
).
- -lens on|off
Ignore all lens shaders if set to off. The default is
on.
- -link "filename" ... -
Like the code command, the link command attaches external
shaders to mental ray, which can then be used as shading
functions. While the code command accepts ``.c'' files as
filename, the link command expects either object files ending
in ``.o'' or ``.obj'', or shader library files ending in
``.so'' or ``.dll''.
- -merge on|off
Ignore all merge epsilons and all connections in the scene
if set to off. The default is on.
- -message module class_list ... -
Enable or disable individual message classes, per module. The
module names are printed at the beginning of every message
printed by mental ray; all can be used to modify the
message classes of all modules. The class_list is a
comma-separated list of classes to print. Supported message
classes are phase, progress, vprogress, time, scene, memory, render, vrender,
resources, network, files, and debug.
The special words default, all, and none are
also supported. A class can be inverted by prepending an
exclamation point. For example, to print less verbose RC
progress messages and make all modules report every file
accessed, specify
- -message rc default,!vprogress all default,files -
- -nomaster3.1
When rendering with multiple hosts, schedule all jobs on slaves
only, if possible. For example, the master host will not render,
tessellate, compute shadow maps, etc; but it will still load
textures of the slaves, and will also collect and save rendered
images. This is useful if the master host also runs front-end
applications that must remain responsive even under heavy load.
- -o "filename"
This is an abbreviation for -file_name.
- -motion_steps steps3.1
Approximate instance motion transformations with steps
segments. This results in a smooth motion path, as if a
similar number of motion vectors had been specified. steps must be a number between 1 and 15; 1 is the default.
- -offset x y
An offset for the rendered
image6.8. The default is 0.0 for both x and
y, which means that the image will be centered on the camera's
Z axis. Positive values translate the image up and to the
right. The offset is measured in pixel units.
- -output on|off
Ignore all output shaders if set to off. The default
is on. File output statements are not affected.
- -photonmap_file "filename"
Use filename for the photon map, in all frames. If
the photon map file does not exist, it is created and saved. If
it exists, it is loaded and used. For multiple frames it is
only created for the first frame and then loaded for the
remaining frames, which can greatly speed up rendering in
scenes where the illumination does not change much, such as
camera flythroughs.
- -photonvol_accuracy nphotonsint [radius]
Controls how global illumination or caustics in participating
media are estimated by looking up the photon map during
rendering. nphotons is the maximum number of photons to
examine and radius the maximum radius to search. if
nphotons is 0, all photons are examined up to the
radius limit. A radius of 0 means that a scene size
dependent radius will be used. The defaults are 30 and 0.0.
- -photon_depth reflect
[refractint [sum
]]
photon_depth is similar to trace_depth except that it applies to photons. If set to 0, no photons will be reflected; if set to 1,
one level is allowed but a photon cannot be reflected again,
and so on. The defaults are 5 5 5.
- -premultiply on|off
Premultiplication means that colors are stored with alpha
multiplied to R, G, and B. This is the default. For example,
white at 10% opacity is not stored as (1, 1, 1, 0.1) but as
(0.1, 0.1, 0.1, 0.1). If turned off, mental ray writes the
colors without premultiplication; in this case color
clipping should also be switched to raw mode.
- -raycl_memory memory
2.1This option sets the amount of memory to be used by the ray
space subdivision algorithm for acceleration data structures to
memory megabytes on each CPU.
- -raycl_subdivision subdiv
subdiv_2d
2.1Controls the ray space subdivision used by the ray
classification2.1 rendering algorithm. The optimal
subdivision is determined automatically; this option can be
used to modify the result. Arguments of 0 leave the calculated
subdivision unchanged, positive numbers increase and negative
numbers reduce the subdivision. subdiv controls general
subdivision; subdiv_2d controls primary and shadow rays.
- -render beginint [endint [incint]]
Render only frames begin through end6.9. If end is
omitted, begin and all following frames are rendered. If
inc is given, only every inc-th frame is rendered. Frame 1
is considered the first render statement in the scene
file; camera frame specifiers are not considered. For example,
4 8 2 will skip the first three frames, then render frame
4, 6, and 8, and omit the rest. It is not an error if the scene
file has fewer frames than requested.
- -resolution x
y
Specifies the width and height of the output
image in pixels. The default is 768 576.
- -samplelock on|off
This option selects whether sampling of area light sources,
motion blur, and depth-of-field is static or dependent on the
frame number. The default is on (static).
- -samples min
max
This option determines the minimum and maximum sample rate.
Each pixel is sampled at least (22 . min) and at most
(22 . max) times in each direction. If min is
0, each pixel is sampled at least once. Positive values
increase the minimum sample rate; negative numbers reduce the
sample rate. The default is -2 0.
- -samples min
max
defmin
defmax
3.1
mental ray 3.1.2 accepts two optional extra parameters that
set the default object sample limits. In mental ray 3.1.2,
objects may constrain sampling of the pixels they cover. The
defmin
and defmax
parameters apply to pixels
where no objects are seen, or all the objects that are seen
have no samples limit. mental ray will never take fewer
than 2min and more than 2max samples, and in areas
with no object sample settings it will further reduce that
range to 2defmin through 2defmax. The defaults are
-2 0 -128 127; the latter two are markers for ``no further
restrictions'' because they are outside the -2 0 range.
- -scanline on|off|opengl
This statement allows turning off the scanline rendering
algorithm to force mental ray to rely exclusively on ray
tracing. This will slow down rendering in most cases. The
opengl mode uses local OpenGL hardware to accelerate
rendering, which sacrifice some accuracy for a large speed
gain. If shadow mapping is also used, -shadowmap
opengl should also be chosen. See page
for
more information. The default scanline mode is on.
- -shadow off|on|sort|segments
Choose the shadow mode, or disable shadows. The default is on.
- off disables all shadows, including shadow maps.
- on enables standard shadows.
- sort enables shadows and sorts shadow intersections before
calling shadow shaders. Some shadow shaders require this.
- segments enables shadows and traces shadow rays like visible
rays. Some shadow shaders require this.
- -shadowmap [on|off|opengl] [only] [rebuild]
[reuse] [motion] [nomotion] -
This option can be used to control shadow maps. The allowed
options are:
- on activates use of shadow maps.
- off disables use of shadow maps. This is the default.
- opengl enables use of shadow maps, and uses local OpenGL
hardware to accelerate shadow map rendering, at a small accuracy
loss. See also page
and -scanline opengl
above; it often makes sense to enable OpenGL in both options.
- only causes only shadow maps to be rendered, without rendering
a color image. By default the color image is rendered also. This
is useful to precompute shadow maps before the actual color
rendering passes begin.
- rebuild causes all shadow maps to be recomputed, even if
they exist in memory from a previous frame or are found on
disk. By default shadow maps are computed only if they are
found neither in memory nor on disk.
- reuse allow the reuse of shadowmaps. This is the default.
If a shadowmap is found in memory or on disk it is used instead
of recomputing it. This only works if object space mode is
selected in the options block of the scene.
- motion activates motion blurred shadow maps. This is enabled
by default if shadow maps are turned on.
- nomotion disables motion blurred shadow maps. This improves
rendering speed.
- -shutter [ delay ] shutter
This option contrils motion blurring. The camera shutter
opens at time delay3.1 and closes at time shutter.
The defaults are both 0.0. If shutter is equal to delay,
motion blurring is disabled; if shutter is greater than
delay, motion blurring is enabled. The normal range is (0, 1),
which uses the full length of the motion vectors or motion
vector paths3.1. It can be useful to set delay3.1
and shutter both to 0.5, which disables motion blurring but
renders with an offset of one half frame, which allows
bidirectional post-blurring in an output shader.
- -T "path1:path2:..."3.x
Specifies a list of directories where texture files will be
searched. The default is the current directory. The list is
colon-separated ( Unix only) or semicolon-separated
( Unix and Windows NT). As with the -I option,
paths introduced with an exclamation point are special: they
substitute the entire directory path of the texture name and
keep only the last component (the file name) when searching.
- -task_size task_size
This option specifies the size of the image rectangles during
rendering. Smaller task sizes are convenient for previewing,
but also increase the overall rendering time and reduce the
effectiveness of edge following. This option can also be
used to optimize load balancing for parallel rendering. If the
task_size is not specified, an appropriate default value
such as 32 is used.
- -threads nthreadsint
Normally, mental ray starts one thread
for each processor in the system. The number of threads can be
changed with this option.
- -time_contrast r g b [a]
The time contrast controls temporal oversampling for
motion blurred scenes. It works similar to the spatial
contrast parameter explained above, but applies to motion
blurring only. The default is 0.2 0.2 0.2 0.2. For fast
motion blur, the time contrast must be set to 0 0 0 and
minimum and maximum sampling must have the same value, such
as 2 2.
- -trace on|off
Normally, mental ray will use a combination of a scanline
rendering algorithm and ray tracing to calculate samples
of the scene. If -trace off is specified, ray tracing is
disabled, and mental ray will rely exclusively on the scanline
algorithm.
- -trace_depth reflect
[refractint [sum
]]
reflect limits the number of recursive
reflection rays. If it is set to 0, no reflection rays will
be cast; if it is set to 1, one level is allowed but a
reflection ray can not be reflected again, and so on.
Similarly, refract controls the maximum depth of
refraction and transparency rays. Additionally, it is
possible to limit the sum of reflection and refraction rays
with sum. The defaults are 2 2 4.
- -v on|off|level
An abbreviation for -verbose.
- -verbose on|off|level
This command controls verbose messages. There are seven
levels: fatal errors (1), errors (2), warnings (3), progress
reports (4), informational messages (5), debugging messages
(6), and verbose debugging messages (7). All message categories
numerically equal to or less than level are printed.
Verbose off is equivalent to level 2 (fatal errors and
errors); verbose on is equivalent to level 5 (everything
except debugging messages).
- -volume on|off
Ignore all volume shaders if set to off. The default
is on.
- -window x_low
y_low
x_highint y_high
Only the sub-rectangle of the image specified by the four
bounds will be rendered. All pixels that fall outside the
rectangle will be left black.
- -xcolor ["control"]
Print colored messages. Error messages, for example, are
printed in red, which makes them stand out much better in
verbose reports. The control string allows customization.
Footnotes
- ... buffer6.1
- Color clipping control is available in mental
ray 2.1 and up.
- ... signs6.2
- Option
insertion is supported by mental ray 2.1 and up.
- ... mode6.3
- The -diagnostic bsp option
requires mental ray 3.0 or higher.
- ... mode6.4
- All -diagnostic options
require mental ray 2.1 or higher.
- ... lanczos6.5
- The Mitchell and
Lanczos filters are supported only in mental ray 2.1 and up.
- ... gathering6.6
- Final gathering
requires mental ray 2.1 or up.
- ... illumination6.7
- Global illumination requires mental ray
2.1 or later.
- ... image6.8
- Camera offsets are supported only in mental ray
2.1 and up.
- ...end6.9
- The -render
option was introduced in mental ray 2.1.36.
Next: 6.2 Inventor mental ray
Up: 6. Command Line Options
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Copyright 2002 by mental images