catt tuct overview

3/20/12 10:00 AMCATT TUCT overview

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CATT TUCT™ overviewTUCT™ was released with CATT-Acoustic v8.0j March 29, 2010 latest update v1.0h with CATT-Acoustic v9.0b Dec 2, 2011.

Overview of the new CATT prediction/auralization software TUCT™:

TUCT™ stands for The Universal Cone Tracer and predicts echograms and room impulseresponses offering several different internal algorithms depending on the room case, ranging frombasic to advanced. In particular it offers very good ways to predict and auralize open cases (outdoorarena etc.) that traditionally often have necessitated making a faked closed model for mostalgorithms to work well, especially for auralization, and cases where flutter echos may be important.Also prediction and auralization in big indoor venues with high absorption will benefit. The corealgorithms are based on various levels and combinations of actual and random diffuse ray split-upand are general so that as the algorithms are further refined and computer speed increasesadditional levels of actual split-up can be incorporated.

TUCT™ relies on the geometry modeling view/check and library handling (absorption, sourcedirectivity, HRTFs, headphones) of the CATT-Acoustic™ main program (CATT-A) that exports a file(.CAG) containing the data necessary and runs TUCT™. Everything previously learned regardinggeometry modeling in CATT-Acoustic™ and old models can thus be directly used but all predictionand auralization is from v9 instead performed by TUCT™ in a simpler, more general and moreflexible way.

TUCT™ is a near total rewrite from scratch but also includes some parts of CATT-Acoustic™ v8 suchas Pixel rendering, an Image source model and Time trace that are adapted and extended to workwith TUCT™ as separate tools in a more flexible and integrated way. Most parts of the CATT-Acoustic™ post-processing have no direct correspondence in TUCT™, they are simply not needed.The few remaining, still useful but not very often used, utilities are kept in the stripped down CATT-A.

Major differences between TUCT™ and the previous CATT-Acoustic™ v8 prediction/auralization:



prediction algorithms are more general and do not rely on reflection growth extrapolation likethe RTCauralization is based on the full reverb tail instead of recreating it in post-processingno separate post-processing stage for auralization required, impulse responses are availablefor evaluation and convolution/listening directly after predictiondisplays measures and graphs for both an energy echogram and an impulse response givingan indirect indication about the prediction reliability at low frequenciesno separate multiple source addition or auralization required, multiple source impulseresponses are available for evaluation and convolution/listening directly after predictionno separate convolution utility necessary, just click Play/Convolve for immediate listening, evenfor multiple sources like in a PA systemfor multiple source (with different sounds) auralization MultiVolver VST™ and MultiVolverWCP™ (offline version) can be used, TUCT saves settings-file for easy integrationno separate relative calibration required to auralize positions within a room with relative levelspreservedcan run in multiple instances (examples: one instance can perform an audience area mappingwhile another performs impulse response prediction for the same model, or one instancepredicts one room and a second instance another room while a third is used to view old results)many types of calculation results can be viewed in parallel (it can e .g. be useful to view theresults of an early part Image source model together with the results of a full calculation toidentify main early reflections)direct or reflected sound can be mapped on all walls and/or audience surfaces at aninteractively selected resolution via the new Surface rendering (similar to Pixel rendering but ata variable absolute spatial resolution allowing free model rotation and rescaling)after a calculation, the effects on STI when changing background noise, overall level/eq andSTI type can be studied interactively including the effect on map statistics, a separatelycalculated noise map can be used as background noise.very few result items have to be decided on before prediction, old results can be recalled,displayed and analyzed again in new ways (in most cases also if new measures oranalysis/display features have been added after the original calculation)simple sequence processing for running several calculation in sequenceno use of PLT-files (in v9 a new PL9-format is used for the main program for geometry/viewcheck and directivrty grahpics, TUCT™ can export to PL9 for presentations or side by sidecomparisons).flexible structure for adding future functionality and measures

Licensing:

for v8 users v9 is treated as an update and has separate Prediction and Full auralizationversions

A basic TUCT™ screen showing main windows (further open windows as icons below)



The Main:Actions window

is an interface to main prediction options and while processing it indicates processing steps, estimated processing timesand % CPU used while processing.



Predict SxR predicts echograms and impulse response for each selected Source x Receiver (SxR)combination and utilizes multiple CPU cores. Three different main prediction algorithms ranging frombasic to advanced. The algorithm choice depends on the room type and the level of details andauralization quality desired. Higher order B-format (2nd or 3rd) can be selected for external decodingand 5-ch mic setups can be used for ITU 5-ch surround. In addition one of two internal methods isautomatically selected to create the impulse responses depending on case:

Map measures predicts measures over a defined audience area receiver map and utilizes multiple CPU cores.Optionally STI and U50 background noise can be from an SPL map of actual noise sources:



Map direct sound predicts direct sound SPL over a defined audience area receiver map and createssource delay and closest source maps, utilizes multiple CPU cores:

For all the above the latest prediction settings are stored on a project basis so when a new version of the same model is made the previosuly used settings are preselected.

Predict SxR and Map measures can be run via a Sequence (batch) processing:



The Main:Show 3D window

Displays the room model with many options such as face coloring and switching on/off 3D elements and save/load ofnamed global or project-specific 3D-views:

Detection and display of ray-leaks due to model errors (gaps or warped planes):

Displays results from direct sound mapping. Mouse-over value readout and auto-scale option:

SPL:



Shortest delay (useful for optimizing source delays):

Source group with shortest delay (useful for optimizing source delays):



Displays results from audience area mapping of measures (SPL, STI, D50, etc. plus SPL(t)). Mouse-over value readoutand auto-scale option:

SPL(t) , i.e. step through the SPL map in time as Echogram, Buildup (forward integrated) or Decay (backward integrated) with variable time steps:

watch each map point echogram and some basic measures as the mouse is moved over the map area:



watch the SPL(r) vs log(r) regression lines for the DL2 and DLf measures (ISO 14257) suggested for use also in open-plan office via ISO 3382-3 (now in draft). Flexible novel implementation via mapping of these DL-measures giving values for many lines in the office and not just one ot two:



In addition to the regression lines behind the standard DL-measures, and the DLf and DL2 themselves, a moreuseful DLf-based measure is introduced where each map point is simply normalized with the freefield SPL at thesame distance:



watch STI/CIS change as background noise, overall eq/level, masking on/off and STI type is varied and backgroundnoise may be from an SPL map of actual noise sources. An STI limit can be selected (see white rectangles belowindicating values < 0.65):



color STI map according to defined ranges (background noise raised) :

watch U50 change as background noise is varied, background noise may be from an SPL map of actual noise sources:



special STI statistics (data can be copied for further processing):

general measure statistics (data can be copied for further processing):



octave-bands, linear wide-band or A-weighted wide-band mapsspreadsheet map export separted into layers (such as a balconyaudience above a floor audience), the map viewed or a selected set of all measures

The Main:Show 2D window

Displays the room model in plan, side and end views with mouse zooming/panning. The Plan/SectionCut z checkbox enables a moveable z (height) cut-plane to make it easier to see source, receiver andaudience details in a room with many ceiling details (see heavy horizontal red line in figures below):



Zoomed and without z-cut:



Displays predicted measures for a selected Source x Receiver (SxR) or Source sum x R (*xR) combination:

watch STI/CIS change as background noise, overall eq/level, masking on/off and STI type is varied:



watch U50 change as background noise and overall eq/level is varied:



mean absorption coefficient graphs with min, max, mean and path distribution:

mean scattering coefficient graphs with min, max, mean and coefficient distribution:



T-30 statistics, useful for understanding a room's acoustic properties and selecting approriate calculation parameters:

octave-bands, linear wide-band or A-weighted measures

Displays echogram-related results for a selected Source x Receiver (SxR) or Source sum x R (*xR) combination, optionally only the energy echogram E can be displayed (red curves below):

squared impulse response, in dB:



energy echogram, plus squared impulse response in dB (for comparison, same integration time). Further options, not shown on this figure, is reflection smoothing and reflection classification (the latter mainly for control rooms):

Schröder curve (backwards integrated IR) with optional, EDT, T15 and T30 regression lines:



Schröder curve normalized with all bands as a backdrop:

Forward integrated IR, indicates sound build-up:



Echo-criteria (EKgrad) for music and speech (green) signals:

a novel type of directional display combining incidence angles and time arrival, variable microphone typesincluding the patent pending Sector mic™:



polar diagrams as function of arrival time, variable integration time and microphone types including the patent pending Sector mic™.



Displays impulse response (IR) related results for a selected Source x Receiver (SxR) or Source sum x R (*xR) combination:

displays IRs for: W, X, Y, Z, X Cardioid, Rotating microphone with selectable microphone types (including the patent pending Sector mic™), binaural, XY-stereo, Blumlein stereo:



Rotating mic. The Rotating mic direction is indicated in the 3D display, with the Sector mic™ the mic sector outline isindicated on walls making it easy to identify reflections



directly play anechoic sounds convolved with IRs (Play/Convolve)play the anechoic material for reference (click Play/Convolve while holding down the left ctrl key))directly play the selected IR "as is"directly play the selected IR convolved with a program material filter, such as AES (Play/Convolve)optionally save as WAV when playing (separate comprehensive IR export available)directly play/save with relative calibration

Main:Impulse Response Detail

Displays detailed IR-related results for a selected Source x Receiver (SxR) Source sum x R (*xR) combination:

IR:

IR squared in dB (raised half cosine windowing applied and shown):



frequency response linear frequency scale:

frequency response log frequency scale:



spectrogram with many resolution options:

The following displays are independent of the Main: windows and can be viewed in parallel.

Pixel rendering

Displays direct or reflected sound at walls and/or audience surfaces at every visible pixel:



Surface rendering

Displays direct or reflected sound at all walls and/or audience surfaces at a selected spatialresolution, since the resolution is not pixel-based the model can be rotated after calculation. Mouse-over value readout and auto-scale option.

Image source model (for specular reflection detail)

image sources can be saved and will be reloaded next time the window is opened interactive reflection paths (click on a reflection and see the path, or step through the echogram in time), view the echogram of multiple sources color-coded according to reflection order, arrival-time or source. Further options, not shown on this figure, isechogram smoothing and reflection classification options (mainly for control room use):



show surfaces involved in each reflection:



display all paths (with an option to show only the wall hit-points):



display all image sources:



view integrated and/or ear-smoothed echogram (to reveal reflections that hide behind each other in theechogram), reflection classification:

Time trace as function of time

including AVI video export ray coloring according to SPL:



ray coloring according to reflection order:

ray coloring according to source:



The following are tools independent of the room model loaded:

WAV-file player

Walkthrough convolver

The Walkthrough convolver uses SIM-file impulse responses that contain all necessary information. For normal auralization in SIM-files are no longer used but they can be exported:



Overall features

2D and 3D clipboard copy and export to Meta, BMP and PL9 (CATT v9 vector graphics)for all 2D and 3D windows.direct printing of main 2D and 3D windows contentsinteractive (mouse click/drag) scale and time change for echograms, impulse response and similar graphs.mouse-over value readout for all graphs and map valuescan directly display and evaluate the echogram/IR and auralize for multiple sources such as in a PA system, an example with two sources A0 and B0 with direct sound arrivals indicated:

room model data for view/export:



calculated measures for view/export (for any combination of sources and receivers):

export of all measures to MATLAB® .MAT formatexport of IRs in several formats including MATLAB, SIM and WAV (separate files or multi-channel).export of binural, B-format (also 2nd and 3rd order), 5-channel (actual mics, coincident, via BPhromer™ via Sector mic™), stereo (XY and Blumlein), mono mics (omni, cardioid, supercardoid, hypercardioid, fig-of-8)B-format WAV IRs can be further analyzed in ReflPhinder™ or convoled in real time via the new MultiVolver VST™released with v8.0j and/or the offline MultiVolver WCP™ convolver (released



with v8.0k) both using the same setup-files.

export for use of IRs in CATT-Walker™:

export of "HeadScape" IRs for head-tracking (for Lake Huron/CP4 users or the Walkthrough Convolver):

batch convolution for any combination of source and receivers and/or source sum IRs making it possible to very quickly listen to a sound system with various configurations. If the WAV-file/Player is open theresulting WAV-files are added to a list for direct playing.

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