Previous developments [1] before version 11
SU2Odeon [2] the plug-in for google sketchup. Works for ODEON version 10 and 11.
The upgrade for ODEON 11 contains important new features:
Parallel processing, gives faster calculations on multicore computers.
Fibonacci Spiral, a perfect distribution of source radiation pattern.
Room acoustic parameter list, display results the way you want.
User defined acoustic parameters, create your own parameters.
ISO 3382-2 compliance, for analysing quality of decay in simulation.
Calculation setup simplified, making it easier to predefine calculation setup.
Automatic grid scaling improved, statistically based colour scaling and "data wash".
Click to select point in grid, when you want to see results faster.
Echo detection, find which receivers are disturbed by echo.
Dynamic diffusion curve, shows how diffusion vary over time.
Show only lost rays, for detection of holes in geometry during raytracing.
Layer support for Extrusion modeller, better management of extrusion models.
Automatic receiver direction for more user friendliness.
Automatic saving of Sketchup model when making several versions of the same geometry.
If the CPU on your computer contains more than one core the calculation of Grid- and Multipoint responses are using the power of the multi core CPU to achieve faster calculation. Up to 10 times faster calculations than version 10 on a computer with 4 cores. The more cores, the faster. The Fibonacci Spiral implemented in Version 11 has a great part of the honour of Odeon version 11 being much faster.
Another enhancement to algorithms is that rays are radiated from point sources according to the Fibonacci spiral [3]; the seeds in a Sunflower are ordered according to the Fibonacci spiral which allows the seeds to be packed in the most efficient way (at the smallest possible area) and, what is interesting for us, with the most even distance between the points (rays) on a sphere.
Using a spiral to determine directions for ray radiation also ensures that there will be no precedence towards or away from e.g. horizontal rays. In earlier versions of ODEON, rays were ordered on a number of dishes or cones with stepwise elevation angles, which indeed gives an even distribution of rays when the ray number goes towards infinity - a problem with the 'dish' method is that it may or may not result in a large horizontal dish of rays which will overemphasize predicted flutter echoes in parallel walled rooms. The Fibonacci spiral is a small but significant change to the algorithms; the number of rays (reflections) needed in order to achieve a certain quality of results can be reduced by approximately 50%!
With this customisation of results you only need to calculate and display the results interesting for your project. Acoustical projects are very different and ODEON users as well, so we have developed a way that you can customize the output to only contain the acoustical parameters that you want to analyze for a project - the Room Acoustic Parameter List.
- Select which parameters you want to be visible in the result and how you want them to be presented. - Define which wide band parameters over different frequency bands you want to present e.g. SPL(A) or averages T20 (250 Hz -1000 Hz). The Room Acoustic Parameter list defines which result parameters will be shown in Single Point response, Multipoint response and Grid response.
In the Room acoustic parameter list you can select the scale to be shown in the Grid response displays and for Multipoint responses you can define if you want to display just noticeable differences for various parameters.
We have uploaded screen videos on YouTube giving a small intro:
Create your own parameters from the impulse response in the Room Acoustics Parameter list. E.g. the single band parameter T25 simply by creating a copy of the T30 renaming it and typing the start and stop level for the calculation. You can also define wide band parameters based on energy intervals like C20 or D80. This can be done in the table called Room acoustic wide band parameters by using the Table called Energy intervals to define the energy intervals for the calculation you need.
In addition to T30 the acoustical parameters stated in ISO 3382-2, T20, C-Curvature, Xi (ξ) are very useful and they are available in Version 11. The parameters C-Curvature and Xi (ξ) help evaluating the quality and validity of the reverberation time which is important as it is not in all cases that the reverberation time is the best descriptor of the acoustics in a room. Typical values of Xi (ξ) are below 5 ‰; values higher than 10 ‰ indicate a decay curve which is far from being a straight line and the value of the reverberation time estimated from the decay curve may be suspicious. Typical values of C-Curvature are below 5 %; values higher than 10 % indicate a double slope on the decay curve.
Firstly some input setup parameters have been removed: "Desired late reflection density" and "decimate late rays" have been removed. The Room setup window has been rearranged: the calculatin parametres which must always be user specifyed for all your rooms is placed in the top of the room setup box - and less used input parameters are placed in the "special settings". A new input box called "Number of late rays" has been added specifying a number of late rays.
The standard colours in grids will be scaled automatically based on statistics, therefore the grid maps will always use the full colour range for better visualisation. A precondition for making this visualisation is, that meaningless results are removed from the grid statistics; so if a grid e.g. is placed inside a wall the value of this simulation will not give any valid result and be deleated from the statistical analyses in the grid. This data wash gives a better colour scale and better statistical analyses of the grid calculation in terms of fractiles etc.
A video about the new grid features is uploaded on Youtube:
Making it easier to find parameters for specific point respones in a grid, you can select a receiver position by left clicking with your mouse. Other shortcuts are available: - you can press the shift key and when you press the left mouse botton down the selected receiver will follow all the movements of the mouse; - press "Ctrl" and left double-click and you can define a new source for the source receiver list; - if you press "Alt" and left double-click you define a new receiver.
Look into a point response and see if an echo is present with the echo criterion according to Dietsch & Kraak (1986).
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In a grid response detect where receivers are disturbed by echo; Echo(Dietsch) ≥1. The elliptical room example is 40 m long and 20 m wide with a source placed close to a focal point. |
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Analyse room diffusion with a new time dependent diffusion function. E.g. for reverberation chamber or concert hall design.
For the 3D investigate ray display a new feature is available displaying over time only the rays leaving a geometry where normally the rays that stay within the geometry are displayed over time. The purpose is to make it easier to detect where rays are lost and thus where there are holes in the geometry.
In the extrusion modeller you can define layers for the objects you draw. This means when you add Materials you can select one layer and add materials to one selected layer at the time. Also you can now add new objects in the middle of the surface list without interferring with the added materials when going back and forth between ODEON and the extrusion modeller.
A line of direction have been added to the receiver, visualising in which direction the receiver is looking to make it easier to understand the auralisation. Also the receiver will have a default direction looking parallel to the x axis towards the Origo of the geometry. This direction can be changed in the Job list as earlier, defining the receiver-towards-source.
When you go to the file menu in ODEON and "copy files" - a new SketchUp model will be saved along with the ODEON ".par-file". This makes it possible for you to edit this new SketchUp file in Google SketchUp and keep the consistency between model and materials inside Odeon.
Links:
[1] http://www.odeon.dk/development-room-acoustics-software
[2] http://www.odeon.dk/su2odeon-plugin-google-sketchup
[3] http://en.wikipedia.org/wiki/Fibonacci_number