Why we made Shape?
Images inspire us. Images lead to ideas. We made Shape as a tool to test inspirations. Play True or False. By finding out whether an idea works or not, either way, we deliver new insight into nature for ourselves and sometimes even for others. That is why with Shape we make images...and more...
"Get your science in Shape !"
What makes Shape different?
We want Shape to be easy to handle and fast to learn, so you can quickly play with the results and change things, before an inspiration evaporates. Shape is different from other astrophysical modeling tools, since it is based on modern interactive 3D modeling technology similar to the one used for special effects, video games and architectural visualization. We combined this technology with custom made rendering, visualization and plotting techniques for astrophysics. Shape continuously evolves, following the users' ideas and needs. It is interactive and the physics is highly customizable through the interface without programming by the user.
What is Shape?
Shape is a morpho-kinematic modeling and reconstruction tool for astrophysical objects. With this software you can quickly construct 3D model structures and directly compare them with data in order to assist in the interpretation of observations. From such a 3D structure model with a model velocity field and emission properties, it generates images and position-velocity (pv) diagrams, channel maps, light echoes, light curves and one dimensional spectral line shape, to mention a few. Wavelength dependent radiation transfer for line emission and scattering on dust is also possible.
What can Shape do for you?
The design purpose of Shape is the modeling and analysis of the 3D structure and kinematics of spatially resolved astrophysical nebulae in a way that can be compared directly with observations of similar real objects. It is particularly suited to study expanding nebulae like planetary nebulae and other structures with clear kinematical signatures like bow-shocks or accretion disks and other streaming flows that can be studied using the Doppler effect. Recently it has been extended to model single scattering such that, e.g., scattering from stellar dust envelopes can me modeled. Radiation transfer of lines with Doppler-effect can be calculated, such that modeling of P-Cygni profiles is possible as of version 3.0. Furthermore, almost all parameters of a model and the observational settings can be animated with time. Apart from the production of very instructive animations, this allows for efficient search of the parameter space of a model.
The model and analysis may be applied for the interpretation of existing observations or the planning and prediction of observations based on a proposed model.
Another potential application is the modeling of complex 3D structures as initial conditions of numerical photo-ionization and hydrodynamic calculations as well as the visualization and calculation of spectral information resulting from such calculations.
The application of Shape as a teaching and learning tool for the interpretation of observations involving images, position-velocity diagrams, channel maps and spectral line profiles may help students and researchers alike become acquainted quickly with this type of data.
Have you got news for us? User publications and utilities page
The webpage for Shape is a window that takes you right to the latest info on applications of Shape in the scientific literature. The page provides access to important up-to-date information on the software as well as model templates and model data from real applications that have been supplied by their authors. You are welcome to make comments and suggestions for future releases of Shape and to share your own results with other users. A discussion group allows quick exchange of questions and answers to news and problems with model building in Shape.
In publications that include models that have been prepared with Shape, credit should be given citing the following original publication:
Steffen, W., Koning, N., Wenger, S., Morisset, C., Magnor, M., 2011,
Shape: A 3D Modeling Tool for Astrophysics
IEEE Transactions on Visualization and Computer Graphics, April 2011 (vol. 17 no. 4)
See also our publications page for a link to the pdf file.
Do you have the right hardware?
The 3D Module of Shape works in conjunction with some parts of your computer hardware, especially the video card. Therefore its performance or ability to function depends on this hardware and its drivers. Shape uses the most recent Java 3D Technology to ensure best results. Make sure your computer hardware is as recent as possible and is ca4pable of this technology. Some systems are known not to comply with these requirements. See the installation instructions for more details on this issue.
The Shape software is provided "as is". No warranty is given for its ﬁtness for a particular purpose. The manual might not be completely up to date for the latest release version. Neither the authors nor their employers can be held responsible in any way for incorrect scientiﬁc or other results that may follow from the usage and interpretation of models produced with Shape.
This manual is under construction!
It will continuously be completed and updated beginning with the most essential and most established parts of Shape to the newer or less frequently used sections.
Please, check back to see if the sections you require have been completed or contact us to let us know your needs. We will be happy to add these sections as soon as possible.
Sections that are marked in RED are future links, information that is still incomplete or features to be implemented.
Users of IExplorer browser: This manual contains gif-animations. IExplorer is not able to reproduce these adequately. We recommend to use other browsers to best view this manual.
General Modeling Strategy
Given a set of one or more images, position-velocity diagrams, channel maps, or other suitable data, a first interpretation of the data should give an approximate "educated guess" of the 3D structure and kinematics of the object. This structure is then reproduced in the built-in 3D module. From this model Shape renders model data for different observational settings like object orientation, slit positions and slit widths, as well as different spatial and velocity resolutions.
The parameters settings for the model and observing setup may be varied automatically to produce a series of different image sets that you can view in an animated form. Viewing animations of image sequences often aids at understanding the effect of the 3D structure and orientation on the spectral information. If the model does not reproduce the observations satisfactorily in any orientation or with any other adjustment that can be made in the main interface, you go back and refine your model taking into account the differences between model and observation. Iteratively you will improve your model until you are satisfied. The process may also reach a limit when you hit the limits of the modeling software or when the assumptions made in the models and their rendering do not apply to the real object.
After arriving at a satisfactory model solution, the result may be inspected in various ways and scientific conclusions regarding the object structure, kinematics and orientation may be drawn.
In most cases observational data of an astrophysical nebulae are not sufficient to derive a unique solution for its 3D structure and kinematics. However, in many such cases, modeling with Shape can still help to gain new insight into the structure of the object. Objects that have relatively simple topology or some noticeable symmetry can usually be solved uniquely. It is recommendable to exploit any hint to symmetries or surface continuities, both, in the images as well as the spectral information even if such properties can be found only in local feature of a complex object.
Knowledge recommended prior to using Shape
In order to profitably use Shape you should have at least basic knowledge about astronomical observing techniques like imaging, spectral line profiles, position-velocity diagrams and/or channel maps. The meaning of seeing and spectral resolution should be known. Of course, for any particular model, the basic physics of the model and it´s effects on observations should be known.
Although very helpful, for simple modeling using the 3D module of Shape no previous knowledge about 3D modeling is required, since there are written and video tutorials available in this user guide.