Ilumbra - Products

Products

Technologies

We at Ilumbra constantly strive to push the limits of what is possible in 3D volumetric visualization. Below you will find a collection of the technologies we have developed and a sneak preview of those we are currently developing to enrich your experience as you view our 3D models. If you would like to integrate any of these technologies in your own planetarium software, please contact us for assistance. This service is offered FREE of charge.

Nesting

One of the major challenges facing interactive volumetric visualization in the dome is the lack of resolution when close up. From a distance the volumes look nice, but as you get close the resolution drops and features begin to look blurry and unresolved. An obvious way of solving this is to create a higher resolution model. The issue with this approach is that the GPU quickly runs out of memory. If for example you want a volume resolution of 1024³, the GPU would need > 4GB of memory.

A major breakthrough came with our nesting technology. The idea is that instead of a single volumetric model, we create several of the same object; each at the same resolution, but of a smaller sub-section of the object. In this way we increase the effective resolution without a big increase to the memory needed. For example a 2 level nested model may have an outer volume at 256³ encompassing the entire object and an inner volume showing only 1/4 of the object also at 256³ resolution. The effective resolution of the inner region is therefore (256*4)³ = 1024³ and the entire model only uses ~100 MB. So as we zoom in and look at the inner region, the resolution is greatly improved at little cost.

The trick with the nesting is to make the transition from the outer volume to the inner volumes seamless. The audience should not be able to see any transition from one to the other as the camera moves into the object. We have solved this problem and written a shader that performs this transition. Please contact us if you would like to have a look!

The images show the results of nesting while zoomed in with our Eagle Nebula volume. The first image is without nesting, whereas the second image includes it. The movie below the images shows the transition of the Eagle Nebula from low to medium to high ressolution

.ONE (Optimized Nesting Environment)

ilumbra has a new file format for an easier management of the growing complexity of nested volumetric 3D models. The Optimized Nesting Environment (.ONE) file format combines all the parameters and textures required for a volumetric model into a single file. The .ONE format provides a seamless delivery and implementation of high-resolution nested models of cosmic landscapes.

Some potential usecases for the new .ONE format may include:

ONE files that contain multiple resolutions of the same volume, thereby allowing the planetarium to load the textures that are most suited to their system.
ONE files that contain different wavelength representations of a single object.
Large landscapes will be possible containing potentially hundreds of high-resolution sub-regions.
Segmentation of models in a single file, similar to what we did with the Cat’s Eye Nebula. The model can be deconstructed and stored in parts to provide a unique teaching experience.
The full floating point texture data can be included in a ONE file. This gives the planetarium vendor the ability to scale the appearance of the volume to highlight, for example, fainter regions that may not be visible with limited byte formatted data.
Multiple equal volume textures can be organized into and referenced from a single texture. This gets around the GPU hard-limit on the number of textures that can be loaded at any given time.

Below are some useful links to get your started on using .ONE. If you have any questions or would like support in implementing this format in your system, please do not hesitate to contact us.

.ONE specification document
.ONE Java Code

Each nested region is rendered in 3-D by our software (bottom panels) and packaged into a single ONE file (top-left). The ONE file contains all the information needed to recreate the entire scene in the digital planetarium (top-right).

Landscapes

Landscapes involve placing multiple volumetric objects within the same scene. Doing so allows one to fly from object to object seamlessly. Landscapes are similar in concept to nesting, except the volumes are of different objects, and not at the same location (although they may still be embedded within each other).

Landscapes run into the same issues as discussed above with nesting. Using a single volume with many small parts would require an unattainably high resolution for a reasonable experience. Using many smaller volumes at different scales allows us to embed many volumes in a single scene without much hit to performance.

Overlays

With the importance of multi-wavelength observations in astronomy, it is necessary to show how objects appear at different wavelengths. To demonstrate the multi-wavelength nature of an object, it is typical to cycle through the different images, flipping back and forth to view the spatial coincidence of certain features.

At Ilumba, we have several objects with multi-wavelength volumes. Switching between these in rapid succession to show the differences is not ideal with these large datasets. It is far better to have them blend as one volume, adjusting the transparency of the different wavelength components to show certain features.

To accomplish this overlay, as with the nesting technology, we load several volumes at once and vary the transparency between them. Again the trick is to do this seamlessly without any noticeable artifacts. We have developed shaders capable of this, allowing the presenter to nicely demonstrate the importance of multi-wavelength observations in astronomy.

The images represent the Andromeda galaxy at three different wavelength bands of light: the first is HII, the second is optical and the third is infrared. The movie shows the smooth transition between each using our overlay shader.

Scattering

Light scattering off of dust is an important visual component in many astronomical images. Producing a realistic volume therefore requires the implementation of scattering. However, scattering is a computationally expensive process and is generally not suitable for real-time interactive volumes.

In order to save rendering time, the scattering is usually done during the model creation; the light scattering off of dust is calculated and then added to the emission of a particular voxel in the volume. The final model therefore has “extra” emission where the scattering was implemented. This works well if the scattering is the same in all directions (isotropic) and doesn’t depend on the camera position.

This, unfortunately, is not always the case. The Pleiades (M45) is an open cluster of stars embedded within a reflection nebula. The scattering from the hot blue stars is strongly directionally dependent, which means the nebula’s appearance will change depending on what angle you view it from. The scattering emission must therefore be calculated for each different position of the camera, which makes a pre calculation during model creation impossible.

We have created a shader that solves this problem by calculating the scattering off of the volume on the fly in real time at reasonable FPS. Since the GPU is restricted to RGBA values, and these are used up already by the emission and absorption, we needed to provide some additional information to the renderer to account for the scattering. Additionally we have introduced some pre-processing steps in the renderer, that allows for real-time scattering during presentation.

The images show a light source (star) illuminating the Orion nebula. The images from first-to-third represent purely back scattering (where the scattered light is directed away from the observer), isotropic scattering (same in all directions) and purely forward scattering (where all the scattered light is directed toward the observer). The movie below the images shows the transition from one to another.

Motion

Interactively flying into and around a volumetric nebula is one of the most memorable experiences when viewing a planetarium show. Now imagine if the object you are flying through is actively exploding, a jet is coming right at you, or you are caught up in the accretion disk of a black hole. At Ilumbra we are actively developing motion volumes to give our audience exactly this experience. The technology is in its infancy, but already we have promising results.

Technically, such a 3D-motion is similar to a 2D-movie. Instead of showing a sequence of images, it shows a time series of 3D-models that have been pre-computed earlier. For the planetarium presenter, the great leap in freedom will be that, instead of having a fixed camera flight path in a pre-rendered movie, the space traveler can freely decide how to move in or out of the scene while the object evolves in time. Playing the sequence backwards, stopping or slowing down at particular times will, of course, also be options.

The images show a sequence that is equally spaced in time. This young stellar object (YSO) was modeled after part of the inner region of Herbig-Haro 111 (HH 111) in the north-eastern region of the Orion-Complex. The movie below the image shows the interactive animation of the rotating inner disk and the expanding jets.

Products

Contact Info