Release version 1.2.6 of Tonatiuh

Tonatiuh release 1.2.6 is now available from the main Tonatiuh website. This new version of the program includes new features that facilitates:

• The modeling of heliostats fields and, thereby, the modeling of solar tower systems;
• The testing of different atmospheric transmittance models;
• The ray casting process, allowing the user to select the objects that should be taken into account during the process.

These new features are:

• A new wizard-type plug-in that facilitates the simulation of solar tower systems. The wizard generates a heliostat field taking as input from the user: (1) a text file with the coordinates of the center of the bases of the heliostats that compose the heliostat field and (2) a component Tonatiuh file describing the geometry of the heliostats (it is assumed that the geometry of all heliostats are the same).
• Several new atmospheric transmittance plug-ins.
• A new reflectance material plug-in, which allows the user to independently define the slope error and the reflectivity ray error of a mirror-like surface.
• The possibility for the user of selecting which of the surfaces in the scene should not be taking into account during the ray tracing process.
• The resolution of a bug that made the program crash when the user tries to "undo" the elimination of a One-Axis tracker.
• The resolution of a bug associated with the definition of the Sun position using the SunPositionCalculator? window (the error is related to an incorrect conversion from degrees to radians).

During the coming weeks we will be developing tutorials showing how to use this new features, and we will be posting them in the tutorials section of the Tonatiuh website.

Thanks for using Tonatiuh and for supporting its development with your comments, suggestions, and questions.

Release version 1.2.4 of Tonatiuh

Tonatiuh release 1.2.4 is now available. This new version of Tonatiuh is another minor release of the program. It incorporates the following features:

• The scripting capabilities have been increased to the point that in this new release of the program any operation and functionality available to the users via the Graphics User Interface is now also available via scripting.
• The resolution of a bug that produced the unexpected closing of the program when the user tries to cast rays before creating the concentrating geometry.
• The resolution of a bug associated with storing a given Tonatiuh "scene" under very particular and uncommon conditions.

As in previous releases we are providing 32 and 64-bit installers of this new release of the program for the three major operating systems: Windows, Linux, and Mac. The installer for the Maxc OS is the same for both the 32 and 64 version of the program. While we have been able to test the 64-bit version of Tonatiuh release 1.2.4 for Windows 7 and Linux, we have not tested the 64-bit version of Tonatiuh for the Mac OS. Thus, please, let us know how it works for you.

In February 20 we expect to release the next version of the program. Please, let us know your suggestions for the new functionality you would like to see incorporated in the program.

Release version 1.2.3 of Tonatiuh

Tonatiuh release 1.2.3 is now available. This new version of Tonatiuh is a minor release of the program. It incorporates the following features:

• The option to specify the transmissivity of the media in which the concentrating system is immersed.
• An optimized ray generation algorithm, that analyzes the concentrating geometry as seen from the ray casting surface (usually a plane perpendicular to the main direction of the direct solar radiation) and determines the areas of the overall ray casting surface from which to actually cast rays.
• An improved version of the Buie's Sunshape plug-in.
• Updated Marble's maps that improve the selection of the plant location and the solar time by the user.

The test carried out so far allow us to conclude that this new version of Tonatiuh is more stable and fast than all previous ones.

Release version 1.2.2 of Tonatiuh

We just released version 1.2.2 of Tonatiuh. This new release of Tonatiuh is another minor release of the program. It solvers a series of minor bugs of the program, and the following major ones:  

• The inappropriate sizing of the ray casting surface. In the previous release of Tonatiuh when the user modified the concentrating geometry, adding or substracting surfaces, the ray casting surface was not resized accordingly. This behavior has been corrected in the present release, so that the size of the ray casting surface is always adjusted to the concentrating geometry in order to increase the probabilities that the rays that are cast hit the concentrating geometry, decreasing the time needed to converge to accurate estimate of variables which are of interest to the user, such as the total power on target, the flux distribution in a given surface, etc.

• The erroneous generation of the seven-tuples of the photon map. In the previous release of the program, the field of the seven-tuple of a given photon that was associated with the side of the surface that the photon was hitting was incorrectly always set to -1, instead of setting it to 0 if the photon was hitting the rear side of the surface or to 1 if it was hitting the front side of the surface. This has been corrected in the present release of the program.

• The undesired possibility for the user of being able to associate a tracker to a TShapeKit. In the previous release of the program the user could select a TShapeKit and then include within it a Tracker element, with the operation resulting in a program crash, since Tracker elements are only intended to be use as child of TSeparatorKit elements. In the present release of the program, the program behavior has been modified to guarantee that the user can only associate a Tracker to a TSeparatorKit.

• The incapacity of the program to open Tonatiuh files containing TShapKit nodes that do not have associated a TShape node. In the previous release of the program, if the user closed a Tonatiuh session having defined a TShapeKit node without associating to it a valid TShape node as a child, the program was not able to subsequently open the given Tonatiuh file any more. The present release correct this.

• The crash of Tonatiuh when the user aborted the operation of creating a Bezier patches TShape node. In the previous release of the program, when a user was defining a Bezier patches TShape node, if she or he was in the process of entering the path to the data file containing the geometric information to create the Bezier patches and decided to abort that operation Tonatiuh crashed. The present release correct this error, and when the user aborts the entering of the geometry data filename, the program just do not create the Bezier patches TShape node.

As a result of correcting all the mentioned bugs, we hope that this new release of Tonatiuh will be a much more stable version of the program than previous ones. 

As promised, we are providing 32 and 64-bit installers of this new release of the program for the three major operating systems: Windows, Linux, and Mac. The installer for the Maxc OS is the same for both the 32 and 64 version of the program. While we have been able to test the 64-bit version of Tonatiuh release 1.2.2 for Windows 7 and Linux, we have not tested the 64-bit version of Tonatiuh for the Mac OS. Thus, please, let us know how it work for you.

In October 23 we expect to release the next version of the program. Please, let us know your suggestions for the new functionality you would like to see incorporated in the program.

The size of the focal spot of an ideal parabolic dish solar concentrator

Release version 1.2.1 of Tonatiuh

We just released version 1.2.1 of Tonatiuh. This new release of Tonatiuh is a relatively minor release of the program. With respect to version 1.2.0, the new release:

• Corrects few minor bugs, and
• Adds a new shape plug-in to the list of Tonatiuh plug-ins.

The main contribution of this new program release is that, for the first time, it offers Window users the possibility of downloading a 64-bit version of the program. Thus, allowing those user to unleash the full power of the program.

We will do our best to ensure that in the next release of the program we will also provide Mac users with a 64-bit version of Tonatiuh. That new release is scheduled by September 20th. 

Release version 1.2.0 of Tonatiuh

We just released version 1.2.0 of Tonatiuh. This new release version of Tonatiuh is a relatively major release of the program. It changes:

• the way the surface from which the primary rays are cast into the concentrating geometry is defined, and
• the way the ray intersections are stored into the photon map.

In previous versions of Tonatiuh, the surface from which the primary rays are cast into the concentrating system was defined by the user, who had the option to select the shape of the surface between a flat rectangle and a flat circular disk, and to define the position and dimensions of the selected shape.

The attempt made in Tonatiuh's version 1.1.5 to assist the user in defining the appropriate dimensions of the selected primary ray casting surface was relatively ill-conceived. In certain circumstances, it resulted in errors in the way primary rays were casts. Furthermore, it did not facilitate the automation of Tonatiuh runs at different sun positions.

In this new release of the Tonatiuh, the primary ray casting surface is always a flat rectangle whose size and position is defined by the program. The way this primary ray casting surface is sized and positioned is simple. For a given Sun position, the bounding box of the concentrating system in the Sun's coordinate frame is obtained, and the primary ray casting surface defined as the side of this bounding box that is perpendicular to the main direction of the Sun rays and is closer to the Sun.

Depending of the Sun position and of the geometry of the solar concentrating system, there may be cases in which the size of the primary ray casting surface may be too large in relation to the region of that surface from which the rays have real chances of intersecting the concentrating system. To cope with those cases in an efficient way, a scheme has been designed and implemented in this new version of Tonatiuh so that no primary rays are cast from regions of the primary ray casting surface from which no primary casted ray will intersect the concentrating geometry. This scheme consist in:

• Pixelizing the primary ray casting surface,
• Projecting into the primary ray casting surface and along the main direction of the Sun rays, the bounding boxes of each of the surfaces that form the solar concentrating system.
• Marking the pixels of the pixelized primary ray casting surface that are shadowed by the bounding boxes projections.
• Casting primary rays to the concentrating systems only from those regions of the primary casting surface that correspond to regions of the marked pixels.
• The refinement of this scheme, to further improve ray casting efficiency, will be one of the goals of next releases of Tonatiuh.

As stated before, this new version of the program, in addition to change the way the primary ray casting surface is shaped, sized and positioned, also changes the way the ray - surface intersections are stored in the photon map. The purpose of this change is to discriminate in which side of the surface the ray - surface intersection has taken place. The lack of this discrimination in previous versions of Tonatiuh led to the necessity of having to use two surfaces instead of one in those cases in which was likely that a surface will receive rays from both sides. Thus, this new functionality will simplify the way concentrating geometries are modeled in Tonatiuh.

Release version 1.1.5 of Tonatiuh

We just released version 1.1.5 of Tonatiuh. This new release version of Tonatiuh is a minor release of the program. It corrects  memory leaks and other minor program bugs. It also incorporates the following new two main features:

• A tracker suited to simulate the tracking behavior of Fresnel mirrors.
• The automatic sizing of the input scene aperture, i.e., the surface from which the sun rays are cast towards the concentrating system.

In this new release, the Linux 64 bit version of the program incorporates for the first time the self-updating functionality of the program that was incorporated in the 32 bit version of the program few releases ago.

If you are using a 32 bit version of Tonatiuh and you already installed in your computer Tonatiuh release 1.1.4, you do not need to download the installer for the new release of the program, just start Tonaiuh's release 1.1.4, go the the Help menu in the menu bar, click on “Check for updates” option, and follow the instructions that will appear on the screen. Of course, for that to work you have to be connected to Internet.

Although our intentions are to develop and make available to everyone the 64 bit version of Tonatiuh not only for Linux, but also for window and Mac OS X. We are encountering difficulties to compile Tonatiuh in a 64 bit Windows and Mac OS X system, and we cannot advance a date at which these difficulties will be resolved.

In defining the features that have been added to release 1.1.5 of Tonatiuh we have taken into account the suggestions of the users expressed both in Tonatiuh's user group and in the corresponding “Tonatiuh raytracer product ideas page” at Google Moderator

Release of version 1.1.4 of Tonatiuh

We just released version 1.1.4 of Tonatiuh. This new release version of Tonatiuh is a minor release of the program. It corrects some memory leaks and other minor bugs of the program and incorporates a large number of internal code improvements targeted to improve the program's speed in all platforms.

This is the first release of Tonatiuh for which, in addition to the 32-bit versions of the program targeted to Windows, Linux, and Mac, we are also releasing a 64-bit binary of the program targeted to Linux.

In the following weeks we will be adding the corresponding 64-bit version of the program targeted to Windows and Mac.

If you already installed in your computer Tonatiuh release 1.1.3, you do not need to download the installer for the new release of the program, just start Tonaiuh's release 1.1.3, go the the Help menu in the menu bar, click on “Check for updates” option, and follow the instructions that will appear on the screen. Of course, for that to work you have to be connected to Internet.

As shown in the following figure, this release is faster than previous releases of the program. Under Windows, it achieves a 22.4% reduction in the average time it needs to cast 6 million rays while simulating the optical behaviour of NREL's Solar Furnace in the three different computers in which the program was tested. Under Linux this average time reduction reached 16.7%.

From Tonatiuh Blog Figures

As always, should you find bugs or errors in the program or in any of its plug-ins, please, take the time to report them, in the "Issues" section of Tonatiuh's website at Googlecode. Furthermore, should you have suggestions to improve the program or increase its functionalities, please, let us know, either by adding comments to this post, or better by opening an appropriate discussion in Tonatiuh's user group.

Best regards,

Release of version 1.1.3 of Tonatiuh

We just released version 1.1.3 of Tonatiuh. This is a minor release version of the program. Its main characteristics are the following:

• It corrects a bug detected in the program's Update Manager of version 1.1.2, which precluded the Update Manger to fulfill its function.
• It introduces changes in the core of the Tonatiuh program that improves and simplified its structure.
• It adds two new shape plug-in to the list of standard Tonatiuh plug-ins: The trough and the surface of revolution versions of the standard non-imaging Trumpet-like concentrator.

Because of the bug in the Update Manager of Tonatiuh version 1.1.2, the new release of the program (version 1.1.3) has still to be downloaded and installed as in previous versions, i.e., by downloading the installer from the "Downloads" tab of the Tonatiuh website and executing it.

As usual, the trough or translational sweeping version of the trumpet-like concentrator plug-in represents only one-side of the translational sweeping trumpet. This allows Tonatiuh users to define complex n-sided trumpet-like concentrators by combining several of these sides and selecting appropriately their input and output lengths.

The following figure shows the parameters that are used in Tonatiuh to define the translational sweeping version of the trumpet-like concentrator shape plug-in added to the new release of the program.

From Tonatiuh Blog Figures

Contrary to others rotational geometry standard Tonatiuh shape plug-ins, the rotational geometry version of the trumpet-like plug-in those not allow the user to define the rotational sweeping angle, but assumes that this angle is always 360 degrees. This limitation will be corrected in future versions of this plug-in.

The following figure shows the parameters that are used in Tonatiuh to define the rotational sweeping version of the trumpet-like concentrator plug-in added to the new release of the program.

From Tonatiuh Blog Figures

As always, if you find bugs in Tonatiuh or in any of its plug-ins, please, take the time to report those errors using the "Issues" tab in Tonatiuh's website at Googlecode. Furthermore, if you have suggestions on how to improve the program or increase its functionalities, please, let us know, either by adding comments to this post, or better by participating on the corresponding discussion of the Tonatiuh users group.

Best regards. Enjoy!

Parameters of the CHC plug-in

In Tonatiuh release 1.1.2, the latest one as of the writting of this post, we have introduced a new shape plugin, the 2D Compound Hyperbolic Concentrator plug-in, which in Tonatiuh is called "Trough_CHC".

The mathematical model defining the CHC implemented in the Trough_CHC plug-in is taken from the following article:

William L. Eichhorn, "Generalized conic concentrators", Appl. Opt. 21, 3887-3890 (1982). http://www.opticsinfobase.org/abstract.cfm?URI=ao-21-21-3887

The plug-in, when added in Tonatiuh as a child to a TShapeKit node, implements one side of a 2D Compound Hyperbolic Concentrator.

From Tonatiuh Blog Figures

As indicated in the above figure, the geometry is defined by the following 5 parameters:

• r1, the distance in the x-direction from the origin of the CHC implicit local coordinate system to the middle of the lower border, oriented in the z-direction and centered around the x-axis. In the negative x-direction, r1 is also de distance in x-axis where the focus of the branch of the hyperbola represented by the plug-in is located (point F in the figure).
• p1,  the distance in the x-direction from the origin of the CHC implicit local coordinate system to the middle of the the upper border, oriented in the z-direction and centered around the x-axis.
• lengthX1, the length of the lower border, oriented in the z-direction and centered around the x-axis.
• lengthX2, the length of the upper border,oriented in the z-direction and centered around the x-axis.
• height, the distance in the y-direction between the lower and the upper border.

By defining lengthX1 and lengthX2 appropiately, it is possible to combine several trough CHC plug-ins to represent a large variety of hyperbolic concentrators. As an example, the figure below shows an Hexagonal CHC constructed using six troguh CHC plug-ins.

From Tonatiuh Blog Figures

Tonatiuh’s website number of visits and bounce rate are growing fast

Tonatiuh’s website started on June 28, 2008. Thus, we are currently in the day 143 of the third year since the opening of the website. With only 39% of the third year of the website passed by, today the number of visits to the Tonatiuh website has exceeded the total number of visits to the website during the previous year. The fact that the number of visits to the Tonatiuh’s website is increasing at an exponential rate is an indication that Tonatiuh is increasingly kwon and used all over the world.

From Tonatiuh Blog Figures

Another indication of the consolidation of Tonatiuh as a reference program for the analysis of the optical and energy behavior of solar concentrating systems is the continuous increase in Tonatiuh's website “Bounce Rate”. According to the information shown in Figure 1, more than 63% of Tonatiuh website’s visitors are recurrent visitors.

Release of version 1.1.2 of Tonatiuh

We just released version 1.1.2 of Tonatiuh. This is a minor release version of the program. Its main characteristics are the following:

• It incorporates an Update Manager, which allows the users to check if there is available a newer version of the program than the one she or he is using, and to download it in case it is available.
• It adds a new shape plug-in to the list of Tonatiuh standard shape plug-ins. This new shape plug-in named "ShapeTroughCHC" allows the user to create trough-like Compound Hyperbolic Concentrators.
• It fixes the error associated with the lack of immediate response of a Tracker to user-induced changes in the transformation of its parent TShapeKit separator or in any of its ancestors.
• It fixed the error associated with the brief appearance of a ghost window when opening the Sun Position Calculator.

Figure 1 shows a view of a parabolic trough working in tandem with a Compound Hyperbolic Concentrator acting as a secondary concentrator.

From Tonatiuh Blog Figures

We are starting a tutorial series to illustrate the use of Tonatiuh

To illustrate the use of Tonantiuh we are starting today a tutorial series, which will be posted in the wiki of the main Tonatiuh website (tonatiuh.googlecode.com).

The tutorial that starts the series will explain how to use Tonatiuh to model and analyze a tower system with 500 one-facet small heliostats.

From Tonatiuh Wiki Figures

This tutorial will explain how to insert "tracker" plug-ins in the modeling of the heliostat field to ensure that when the user changes the sun position the heliostats are  automatically reoriented so that they keep directing their reflected sunlight towards the receiver located on top of the tower.

In addition, the tutorial will also explain how to use the scripting capabilities of Tonatiuh to automate the generation of an optical efficiency matrix for the solar heliostat field.

To access the index of the tutorial series, please, follow this link.

Please, give us feedback, so that we can continue improving Tonatiuh, and providing you the tools and information you need to use it.

Best regards,

Improved instructions to install Tonatiuh's IDE under Windows

One of the many good things of Tonatiuh is that it is build upon one of the best set of open source libraries available (Qt, Simage, Coin3D, SoQt, Marble, Berkeley DB). This allows the program to benefit from the continuous improvement and increase in functionality of those libraries and their related tools.

Under Windows, the recent improvements on the installation and set up tools of the MinGW/MSYS compilation and linking environment and of the Qt, Coin3D and Marble libraries has resulted in a drastic simplification and a dramatic reduction in the time needed to install and configure the Tonatiuh's development environment.

Now, if you follow the updated instructions posted on the Wiki of the Tonatiuh website regarding how to install and configure the development environment of Tonatiuh under Windows XP, Windows Vista, and Windows 7, you will need just two to three ours to:

• Install the complete development environment,
• Download Tonatiuh's source code from its Googlecode SVN server,
• Build the latest stable version of the program from its source code, and
• Be ready to contribute to the improvement of the program, should you decide to do so. 

These are good news to any one interested in being able to build the latest version of Tonatiuh without having to wait until the next official program release, or to any one interested in collaborating in the development of the program.

To access the updated wiki instructions regarding how to install and configure Tonatiuh's development environment, please, go to this link.

Release of version 1.1.1 of Tonatiuh

We just released version 1.1.1 of Tonatiuh. This is a minor version of the program. The main characteristic of this release is that it incorporates the most recent versions of all of the program's supporting libraries: Qt, Simage, Coin, SoQt, Marble and Berlkeley DB.

As shown in Figure 1, this release is faster than version 1.0.0. Under Windows, it achieved a 14.1% reduction in the average time it needed to cast 6 million rays while simulating the optical behavior of NREL's Solar Furnace in the three computers in which the program was tested. Under Linux this average time reduction reached 15.6%.

From Tonatiuh Blog Figures

The release fixes several small program bugs and introduces both a new version of the Buie's sunshape plugin and a new version of the spherical rectangle plug-in. It also slightly changes the way the user can use Marble to select a given location on the Earth.

As always, if you find bugs in Tonatiuh or in any of its plug-ins, please, take the time to report those errors using the "Issues" tab in Tonatiuh's website at Googlecode. Furthermore, if you have suggestions on how to improve the program or increase its functionalities, please, let us know, either by adding comments to this post, or better by participating on the corresponding discussion of the Tonatiuh users group.

Best regards. Enjoy! 

Release of version 1.1.0 of Tonatiuh

We just released version 1.1.0 of Tonatiuh. This is a relatively major release of the program. It incorporates a signficant new feature to Tonatiuh: SCRIPTING.

From now on, you will be able to automatize some of the recurrent taks that you do with Tonatiuh by writting your own scripts. This new release of the program introduces scpripting just as a proof of concept, we will be expanding the scripting capabilities of Tonatiuh in future program releases.

In addition to scripting, this new release of the program, corrects several detected bugs, improves the general (circumsolar ratio) sunshape plugin, facilitates the storage of Tonatiuh results (photon maps), and makes it possible to inmediately open, within Tonatiuh, any Tonatiuh file just by cliking on the file -once the user associates, in the Operating System he or she is using, the Tonatiuh file extension with the Tonatiuh program.

As always, if you find bugs in Tonatiuh or in any of its plug-ins, please, take the time to report those errors using the "Issues" tab in Tonatiuh's website at Googlecode. Furthermore, if you have suggestions on how to improve the program or increase its functionalities, please, let us know, either by adding comments to this post, or better by participating on the corresponding discussion of the Tonatiuh users group.

Best regards. Enjoy!

OpenSolaris version of Tonatiuh 1.0.1

As indicated in a recent post, we have added OpenSolaris to the list of operating systems for which Tonatiuh is targeted.

If you are interesting in using Tonatiuh under OpenSolaris, please, do the following:

1. Go to the "Downloads" section of the Tonatiuh website at Googlecode.com.
2. Download the archive file "tonatiuh-opensolaris-1.0.1.tar.gz" in a computer running OpenSolaris and extract its content.
3. Find the shell file "Tonatiuh.sh" and execute it.

We have been able to test the above procedure in only one PC running OpenSolaris. Thus, if the procedure works for you, please, let us know. If it does not work, please, also let us know, and if possible, please, provide us with the details of what went wrong, so that we can try to fix it.

Release of version 1.0.1 of Tonatiuh

We just released version 1.0.1 of Tonatiuh. This minor release:

• Fixes some programming bugs that, when running Tonatiuh under the MAC OS X, resulted in the user not being able to maximize the program's main window, or in some plug-ins not being loaded.
• Improves the implementation of the ShapeFlatDisk so that now when using this shape as the starting surface from which to cast solar photons into the solar concentrating systems, the origin of the photons are much more uniformly distributed upon the flat disk surface that under the previous implementation of the plug-in.
• Includes two new shape plug-ins (ShapeSphericalRectangle, and ShapeBezierSurfaces).

• Includes one new sunshape plug-in (SunshapeBuie).
  

In future posts, the functionality added by these new plug-ins will be presented, and the use of the plug-ing explained.

As always, if you find bugs in Tonatiuh or in any of its plug-ins, please, take the time to report those errors using the "Issues" tab in Tonatiuh's website at Googlecode.

Best regards. Enjoy!

Tonatiuh is available for OpenSolaris

During the last four weeks we were busy, not only improving Tonatiuh and fixing the bugs reported by the users, but also adding OpenSolaris -a unix-derived operating system (OS) promoted by Oracle- to the list of OS for which Tonatiuh is available.

Very soon the instructions to develop and build Tonatiuh for OpenSolaris, using Oracle's C++ compiler, will be added to the wiki of the main Tonatiuh website.

From Tonatiuh Blog Figures

Being able to use Oracle's standard C++ compiler to make Tonatiuh available for OpenSolaris will help us to ensure that we are developing the program in standard C++, and that we are not introducing compiler-specific dependencies in our code.

With this new addition, the number of OS for which Tonatiuh is available reaches four:

• Windows (XP, Vista, and 7),
• Mac OS X,
• Linux (Ubuntu, Kubuntu, Open SuSE), and
• OpenSolaris.