Overview

The OWL 360 Camera and Movie Render Queue integration provides a wide range of capabilities when rendering Domemaster content.

This article covers various practical steps to think about when creating content for domes/ planetaria to help creators make the best quality videos.

In general, we recommend previsualisation!

You can live-render your content direct from the OWL 360 Camera to a headset via NDI and watch your complete sequence before running any renders. This will let you refine details to get your output just right.

Previsualisation

The OWL 360 Camera/ Component is excellent for pre-visualisation because it color-matches your Movie Render Queue output, while also rendering in real-time.

So instead of waiting for hours/ days to see what your render will look like, you can preview it in real-time on a screen or headset to get your shots perfectly as you want them before initiating your final pixel high-resolution output.

This is particularly useful for thinking about audience details like the proximity of objects to the camera, scale of your scene to the viewer and the pace of the camera through your levels:

• You can live-stream the Render Target of the camera through our Spout/ NDI Senders to venue previsualisation software, watched either on Desktop or in a VR Headset.

• This lets you run your sequences in Unreal and watch your full content in real-time.

• With DLSS enabled, it should be possible to have 4K resolution live output at 20-30FPS which is very effective for previs.

• You can use the DomeViewer software both in Oculus or Windows to preview your content in a digital twin of your venue (either birds-eye or as an audience member), and you can set the dimensions and viewing angle for a very precise experience:

  

• You can also build a digital twin of your venue in Unreal and use the Media Input Wizard to set up an Unreal Media Plate with the correct Mesh of your venue’s screen.

• You can then stream the 360 Camera/ Component output into your digital twin via the OWL Spout/ NDI Senders and it will play with perfect color accuracy in your virtual venue.

Playback

• Dedicated media players/ servers are recommended for media playback of Dome content.

• Most Dome venues will have a playback software they use and should provide a specification for the file types they require.

• You can use the Burn-Ins capability in the OWL Movie Render Queue tools to add show name, timecode, frame number, text and copyright which are normally displayed in the upper left-hand corner, with the show name in the bottom left-hand corner and the other corners normally left blank.

Dome Formats

Projection Types

• The default projection type for Domes/ Planetaria content is a Domemaster which is a type of Fisheye projection.

  • This is by far the most widely used format and rendering with it ensures compatibility with almost any standard Dome.

  • The distortion in the projection increases the further away the image is from the Zenith (the top middle point of the dome), with the image at the sides stretched and curved:

    

• In some venues, such as the Sphere Las Vegas, an Equirectangular projection with narrowed horizontal and vertical FOV is used because it is more appropriate to the projection surface (part of a sphere).

  • This projection has a very different distortions with the top and the bottom stretching the most and the centre of the image (including both sides) having relatively little distortion:

    

  • You can create a projection like this with our Custom Mask option:

    

• A Fisheye VR180 projection will only work in a dome for stereoscopic content if the audience is lying down and therefore their viewpoint is the top of the hemisphere (the Zenith).

  • In most domes the focal point is actually one of the sides of the dome, at the edge of the projection where the stereo effect is no longer effective.

  • For this reason, stereoscopic domemaster requires it’s own projection type which we hope to support in the future.

Field of View

• You can use the Dome Angle slider to set the correct FOV value for your content/ venue:

  

• The standard Dome architecture is a hemisphere with 180 degrees FOV, which is also the default setting for our Domemaster projection:

  

• However, some domes are larger than a hemisphere, with edges that encircle viewers, such as SAT Montreal which has a FOV of 210 degrees:

  

• It is possible to set a higher or lower Dome Angle value when making content for a standard 180 degree venue.

  • The effect will be either to increase or reduce the content in the peripheral vision of the viewer (see below for more details).

  • Adjusting by small values such as ±10 degrees is normally enough to have a large visual effect.

    

Viewing Angle

• Different domes place the audience at different angles to maximise the amount of screen that is in their focused and peripheral vision.

• It’s important to think about the position of the viewers because it should determine where you place any visual content that you want the audience to focus on.

• The focus area for humans is about 50 degrees wide and tall, beyond that there is another 40 degrees above and below in peripheral vision (vertical FOV) and 80 degrees side-to-side (horizontal FOV)

• In addition, content on the side of the dome naturally gets stretched so is less effective for subject matter.

• While the typical recline angle for seats in Domes is 30 to 45 degrees, this is not standardized across all venues so films can require re-rendering to ensure that the viewer is always looking at the desired part of the screen.

• You can add Camera Rotation easily using OWL 360 Camera Actor, such as in this example where the view is at -45 degrees from the Zenith of the Dome, so the audience can look over the horizon:

  

• In general it’s better for content to develop across the horizontal plane because it’s more comfortable for viewers to turn their heads left and right rather than constantly having to look up.

• However, there is always dramatic effective to use the Zenith of the Dome, sometimes for special shots or content, since this is the central point of the screen.

Projector or LED

• Projector and LED domes process color differently, and so content should normally be rendered bespoke for each.

• Since projectors rely on reflecting color, in domes they have an issue with bouncing light, which can wash out vibrant colors and turn blacks into greys.

• For this reason it’s better to avoid large bright areas in content made for projectors and to keep the average level of bright pixels low.

• In LED domes, you can render much higher contrast content, since blacks will show correctly, and therefore a much higher contrast ratio is possible and you can push bright areas, brightness generally and use a wide range of vibrant colors.

Resolution

• Different Domes feature different resolutions, all the way up to the Sphere Las Vegas, which is 16K!

• If you are rendering content for a lower resolution dome, such as 4K, you can enhance the detail and sharpness by using super-sampling.

• If you are using Temporal Super Resolution (TSR) as your anti-aliasing algorithm in Unreal, you can use a Console Variable to set a higher screen percentage so that the TSR algorithm has more pixels to choose from than you need for your resolution.

• This stops any smudging in pixels where the algorithm might not have enough color information and so provides a much cleaner image, even at lower resolutions.

Frame Rate

• In all immersive content a higher frame rate is generally better because it reduce motion sickness and ensures that visual content doesn’t ghost to the eye as both content and the eye scan in your peripheral vision.

• The ideal frame rate is therefore 120FPS but the minimum recommended is 60FPS, 90FPS can also be very effective.

• The faster the motion of the camera in the scene, the higher the mimimum FPS will be.

• If you want fast moving action footage with a lot of motion blur, 120FPS is likely required to stop image blur in the audience’s peripheral vision.

• By contrast, if the Dome you are rendering for has a low FPS capability, you should be very careful with camera motion to provide a good viewing experience for your audience.

Content Creation Tips

Domes are a unique immersive content format which present visual information to the viewer very differently to both 2D cinema and Virtual Reality headsets.

Creators need to think carefully about the way the screen distorts the viewer’s perception of size and scale and use tools such as field-of-view, focus, scale and framing, often in an artificial way, to generate the desired visual effect.

Working in Unreal Engine offers very exciting possibilities due to the ability to manipulate these elements in a way not possible when working with real-world cameras, to offer a significantly enhanced visual experience.

Remember to use the previs capabilities of the OWL 360 Camera to watch your content back in real-time as you make it!

That allows you to understand exactly what the audience experience will be like and to tweak the elements below before your final render.

Examples

• Many examples of Fulldome films can be found on the FullDomeDatabase Website.

• Watching these examples can guide on different cinematic techniques that work effectively for Dome content.

Distortion

• Fisheye/ Domemaster projections are highly distorted around the edges.

• You should therefore think about camera movement, object placement and proximity to accomodate for the distortion that will happen around the edges of the dome so that it doesn’t limit the impact of your visual content.

  • For example, this arch is close to correct when in the centre of the dome:

    

  • But at the edges, when the camera is closer to it, it becomes highly distorted:

    

Scale

• Another distortion can happen with large objects which can become decontextualised when you get too close to them due to the horizon disappearing.

  • For example, the ball here is clearly huge when viewed from afar:

    

  • However, when you get too close to it, it becomes decontextualised and it’s hard to understand it’s scale:

    

• To manage this you should increase the size of the object rather than (or along with) the proximity of the camera. This will give the impression that you are getting closer while still preserving the sense of scale:

  

• You can also increase the Dome Angle of the camera to add more horizon elements into the peripheral vision which will provide scale.

• Alternatively you can approach objects so that they aren’t in the center of the frame, always keeping a portion of them below the horizon line.

Rotation

• The audience already have three degrees of freedom, since they can look around the Dome so pitch, roll and yaw should be used rarely or not at all.

• The viewer should be given full freedom to control their point of view, and visual queues such as lighting changes or movement of subjects are more effective for guiding the viewer to look in an intended direction, than camera rotation.

  • Yaw: This is possible to use but must be very slow and should be combined with an anchor element such as a cockpit or a slow moving element in the center of the focal zone.

  • Pitch: Rotating the camera upwards is possible but should be used sparingly. Rotating the camera down is verylikely to cause motion sickness so should be avoided.

    • If you want to show something below the camera then it’s better to move the camera vertically downwards in a straight line rather than rotate it,

  • Roll: This should never be used since it will cause nausea.

    • If you want to animate the movement of a vehicle etc in this way then it is better to move to a third-person perspective so the audience can view it moving while also looking at a stable horizon.

Motion

• Movement should generally be slow and deliberate so that the audience can follow it easily to avoid nausea.

• The distortion of the Domemaster projection means that the same object will move much more slowly in the center of the screen than on the edges and so fast movement (for example forward through space) can create nausea due to the brain trying to process these two different speeds at the same time.

• You can use this ‘warpspeed’ distortion effect to your advantage however, if it fits your content, since you can make the audience feel like they are getting sucked into space.

• Acceleration should be linear and slow, with long, soft animation curves.

• Camera shake can be employed at specific moments for dramatic effect but shouldn’t be combined with other movement.

  • For example a vehicle shouldn’t bounce around while the audience are in it.

  • If you want to show it moving in that way then it should shift to a third person perspective while the audience watches it over across the landscape.

Framing

• You need to think very carefully about how the Dome distorts the image to decide where to present relevant visual information to your viewer.

• Both the size/ angle of the Dome and the viewing angle of the seating must be considered to get this right.

• Even though the top of the dome will offer the least distortion, placing the main content there will make for a poor viewer experience due to excessive neck bending, unless viewers are able to lie down and look directly upwards.

• In general, in a seated dome, you should aim to place your main content around 30-45 degrees above the horizon line of the dome.

Distance

• If you get too close to objects they will show across the whole span of the dome which can make them look very distorted, the part in the Zenith will bulge towards the viewer and the scale of the part around the edges of the dome will be warped.

• It’s therefore better to keep objects at a distance from the camera.

• If you want to show detail on an object then you can increase it’s scale, rather than move the camera closer/ too close towards it.

• You can use this distortion artististically, for example, if you zoom into a massive sphere, it will look like a tiny marble isolated with space all around it.

• You can use the Dome Angle to increase the FOV if you need to get close to objects so that you retain more horizon.

Focus

• Normally, depth-of-field should be kept infinite in to avoid conflict with the lenses of the headset.

• You can use the OWL 360 Camera to set a specific focal distance which can be effective for highlighting talent or certain objects in the scene as it will align the focus of the camera to their distance from it.

• You can change this distance if you fade out to a new shot position, but it should not be changed mid-shot as it will cause nausea.