Maxwell Studio LatLong Stereo
Overview
This is the Domemaster3D wiki section for the Maxwell Studio 3.2 integrated version of the LatLong Stereo shader.
Known Issues
The Parallax Distance control in the initial Maxwell 3.2 Beta is in a different unit scale from the Maxwell Studio scene scale.
In Maxwell Studio if the Separation control is set to 6.5 cm, you will want to have the Parallax Distance set to 3600 units in your Maxwell set up to equate to the same rendering result you would get in the traditional Maya/Domemaster3D shader settings of Camera Separation 6.5 / Parallax Distance 360.
This is due to the fact that Maxwell Studio uses meters internally and the scene translation feature in the lens shader needs to be updated to synchronize the scene units translation with the camera separation and parallax distance controls.
Lat-Long Stereo Shader Controls
Lens
Near the top of the Optics section is a Lens attribute that lets you switch the current lens shader model.
For this wiki page we are focusing on the LatLong Stereo lens model that outputs an latitude longitude format stereo image that is also called an equirectangular or spherical format.
A LatLong image usually covers a 360 ° horizontal x 180 ° vertical area and is rendered to a 2:1 aspect ratio like 2048x1024 px, 3072x1536 px, 4096x2048 px, or 8192x4096 px.
Type
The type attribute lets you choose whether the lens shader will output either the center view (which has the stereo settings disabled), or you can choose to render a left or right stereo camera view.
Field of View Vertical
Controls the vertical FOV angle (in degrees) of the rendered Latitude/Longitude image.
Field of View Horizontal
Controls the horizontal FOV angle (in degrees) of the rendered Latitude/Longitude image.
Flip X
This checkbox will flip the view horizontally.
Flip Y
This checkbox will flip the view vertically.
Parallax Distance
This control adjusts the distance in the scene where the depth converges in the left and right eye views.
Objects placed closer to the camera than the Zero Parallax Distance appear to come out at the audience. Objects placed further away from the camera than the Zero Parallax Distance value appear to the viewer as if they are existing beyond the physical "wall" of the screen they are viewing.
Right now in the initial Maxwell 3.2 Betas this Parallax Distance control is measured in millimeters (mm) so you should enter a starting value of 3600 units if you are using a typical 6.5 cm camera separation value.
Separation
The initial camera separation of the left and right cameras in centimeters. This value would typically be set to a number between 6 to 6.5 centimeters for a real world scale scene.
For a "Hyperstereo" effect that can make the details in the distance pop up more the separation value can be increased greatly as long as objects aren't placed to close to the camera as this would cause eye strain.
You can also reduce the cameras separation attribute and the parallax distance smaller if you are placing objects close to a scene or rendering a scene set in a tiny microscopic world.
This stereo effect is typically reduced at the pole regions using the separation map texture to remove a "swirl" artifact that would otherwise occur.
Separation Map
A texture attached to this control has an effect of multiplying a 0-1 range value against the current camera Separation attribute.
This texture map control is meant to be used with an RGB image that has a black to white style grayscale texture applied. The image is used to control the amount of 3D effect, and eliminate it where desired.
This topic is discussed further down on this wiki page in the Screen Space Texture Maps section.
Zenith Mode
This attribute allows you to adjust the LatLong Stereo lens shader to work with either a horizontal orientation (Zenith Mode OFF), or an upwards / vertical orientation (Zenith Mode ON) that lines up with the upright view orientation of the Fisheye Stereo shader.
Screen Space Texture Maps
You can control the stereoscopic effect seen in the Lat-Long Stereo and Fisheye Stereo shaders with the help of control texture maps.
These texture maps work in the Maxwell stereo lens shaders and are designed to use the same stereo control texture maps as the original Domemaster3D shaders do.
The stereo control texture maps are typically an RGB image (like a PNG texture) that have a black to white color in the image which represents the area of the rendered frame that will have full stereo effect or a reduced stereo effect.
The control texture maps take care of "swirly" artifacts that would occur in the pole zones during the turning "panoramic" stereo camera rendering phase that is used to make a continuous and seamless 360 degree stereo effect.
The control maps are applied by the Maxwell lens shaders using "screen space" coordinates which means they are directly mapped 1:1 with the areas in the final rendered image.
In a separation texture map pure black means no stereo effect will appear in that area, and white means the stereo effect will be at full strength. The areas of shading between pure black and white have a feathered out stereo effect to gradually reduce the stereo depth. For a LatLong stereo control map, it really is just a simple gradient that chooses where in the image you want to start fading out the stereo effect.
The sample control texture maps files that are included with the regular Domemaster3D shaders are installed to the following location:
(These texture maps can also be used with the Maxwell Stereo lens shaders too)
Domemaster3D on Windows Images
C:\Program Files\Domemaster3D\sourceimages\
or
Domemaster3D on Mac Images
/Applications/Domemaster3D/sourceimages/
or
Domemaster3D on Linux Images
opt/Domemaster3D/sourceimages/
The Separation Map
The texture "latlong_separation_map.png" is for feathering out the stereo effect in the pole regions in a latlong rendering. The zenith or upwards sky facing pole region is at the top of the texture map, and the nadir or downwards facing pole region is on the bottom of the texture map.
Sample Ma~xwell Studio Scene
To demonstrate how the LatLong Stereo shader works inside of Maxwell Render, a Maxwell Studio .mxs based version of the classic Maya/Domemaster3D CubeX scene has been prepared.
You can download this example file here:
maxwell_latlong_stereo_cubex.zip
LatLong Stereo Image
(The left and right views were merged to red/cyan anaglyph for inline wiki based viewing)
Maxwell Studio Fisheye Stereo
Andrew Hazelden edited this page on Nov 26, 2016 · 7 revisions
Overview
This is the Domemaster3D wiki section for the Maxwell Studio 3.2 integrated version of the Fisheye Stereo shader.
Fisheye Stereo Shader Controls
Lens
Near the top of the Optics section is a Lens attribute that lets you switch the current lens shader model.
For this wiki page we are focusing on the Fish Stereo lens model that outputs an angular fisheye format stereo image that is also called an domemaster frame if the field of view is set to 180 degrees (diagonally measured), or a light probe / angular map if rendered to a 360 degree field of view (diagonally measured).
An angular fisheye image is typically rendered to a 1:1 aspect ratio like 2048x2048 px, 3072x3072 px, 4096x4096 px, or 8192x8192 px.
Type
The type attribute lets you choose whether the lens shader will output either the center view (which has the stereo settings disabled), or you can choose to render a left or right stereo camera view.
Field of View
The field of view control adjusts the focal length of the angular fisheye rendering. By default a fulldome image has a 180 degree field of view.
If you want to include a bit of the "ground" in the scene, it is possible to increase the field of view slightly to a value like 220 degrees and the final rendered image will still look acceptable in a dome.
Tip: If you want to render a full 360 degree angular fisheye image which is also known as an HDRI light probe you will need to update the custom maps that are applied to the stereo separation, and turn attributes.
Separation
This controls the camera separation / stereo base of the stereo camera rig and is always measured in centimeters in Maxwell Studio.
This value would typically be set to a number between 6 to 6.5 centimeters for a real world scale scene.
If you are working in a scene that has a large scale, or a scene with a small scale, you can freely change the dome radius, and camera separation values to match the world size and keep the stereoscopic effect comfortable on the eyes. However, when you are tuning the camera separation value and the dome radius values, you should keep a basic ratio between the two controls.
The default settings have a 55:1 ratio where the dome radius is set to 3600 mm, and the camera separation is set to 6.5 cm. This would represent the scale of a 22 foot dome. If you wanted to have the same 55:1 ratio on a much smaller scene you could set the dome radius to 3.6 and the camera separation to 0.65 units.
Some artists prefer to use a higher ratio value 110:1 with a dome radius of 7200 mm with a camera separation of 6.5 cm. This would represent the scale of a 47 foot planetarium dome.
Fulldome artist Aaron Bradbury http://www.luniere.com/ has suggested a ratio of approximately 154:1 gives a near ideal fulldome stereo result (with a 0.372 degree maximum separation on the rendered image). This would equate to a dome radius of 10000 mm, and a camera separation of 6.5 cm.
Separation Map
A texture attached to this control has an effect of multiplying a 0-1 range value against the current camera Separation attribute.
This texture map control is meant to be used with an RGB image that has a black to white style grayscale texture applied. The image is used to control the amount of 3D effect, and eliminate it where desired.
This topic is discussed further down on this wiki page in the Screen Space Texture Maps section.
Vertical Mode
The vertical mode control can be used if you have a curved fulldome screen that is mounted vertically against a wall and the viewers look forward at the screen.
Dome Radius
The Dome Radius control can be thought of as a fulldome equivalent of the standard zero parallax zone in Maya's default stereo camera rig. This control adjusts the distance in the scene where the depth converges in the left and right eye views.
Objects placed closer to the camera than the dome radius distance appear to come out at the audience. Anything located in and around the dome radius distance appears in stereoscopic 3D as if it is sitting right on the wall of the fulldome theater screen. Objects placed further away from the camera than the dome radius value appear to the viewer as if they are existing beyond the physical wall of the planetarium screen.
Head Turn Map
A texture attached to this control has an effect of controlling the head rotation as the panoramic image is rendered. This is especially important in the pole regions of an angular fisheye frame.
This texture map control is meant to be used with an RGB image that has a black to white style grayscale texture applied. The image is used to control the amount of 3D effect, and eliminate it where desired.
This topic is discussed further down on this wiki page in the Screen Space Texture Maps section.
Dome Tilt Compensation
This control enables or disables the effect of the Dome Tilt attribute.
Dome Tilt
This control can be used to compensate for a tilted fulldome theater screen. If your theater has no tilt angle you can leave this value at zero.
Head Tilt Map
A texture attached to this control has the ability to adjust the stereo rendering method and push the pole region backwards past the zenith area.
This texture map control is meant to be used with an RGB image that has a black to white style grayscale texture applied. The image is used to control the amount of 3D effect, and eliminate it where desired.
This topic is discussed further down on this wiki page in the Screen Space Texture Maps section.
Screen Space Texture Maps
You can control the stereoscopic effect seen in the Lat-Long Stereo and Fisheye Stereo shaders with the help of control texture maps.
You can control the stereoscopic effect seen in the Lat-Long Stereo and Fisheye Stereo shaders with the help of control texture maps.
These texture maps work in the Maxwell stereo lens shaders and are designed to use the same stereo control texture maps as the original Domemaster3D shaders do.
The stereo control texture maps are typically an RGB image (like a PNG texture) that have a black to white color in the image which represents the area of the rendered frame that will have full stereo effect or a reduced stereo effect.
The control texture maps take care of "swirly" artifacts that would occur in the pole zones during the turning "panoramic" stereo camera rendering phase that is used to make a continuous and seamless 360 degree stereo effect.
The control maps are applied by the Maxwell lens shaders using "screen space" coordinates which means they are directly mapped 1:1 with the areas in the final rendered image.
In a separation texture map pure black means no stereo effect will appear in that area, and white means the stereo effect will be at full strength. The areas of shading between pure black and white have a feathered out stereo effect to gradually reduce the stereo depth.
The sample control texture maps files that are included with the regular Domemaster3D shaders are installed to the following location:
(These texture maps can also be used with the Maxwell Stereo lens shaders too)
Domemaster3D on Windows Images
C:\Program Files\Domemaster3D\sourceimages\
or
Domemaster3D on Mac Images
/Applications/Domemaster3D/sourceimages/
or
Domemaster3D on Linux Images
opt/Domemaster3D/sourceimages/
The Stereo Control Maps
The textures "separation_map.png", "turn_map.png", and "head_tilt_map.png" are for use with 180 degree angular fisheye renderings which are also called domemaster frames due to their use in planetarium "dome" theaters.
When rendered, these 180 degree angular fisheye images typically have a black circular mask applied to the perimeter of the frame so anything outside the circular area in the final rendering is cut off.
separation_map.png
The 180 degree angular fisheye separation map texture may look a bit strange but what it is indicating is the area just behind the viewer's head when seated in a dome theater has the stereo effect reduced where the viewer may be fully tilted back in their chair and looking back past the top pole region of the theater.
head_tilt_map.png
The head tilt map has two shaded areas that are used to cause the stereo rendering settings in the lens shader to adjust for the fact a seated viewer in the planetarium theater is rolling their head at a slightly tilted angle when looking to the far left or far right area on the "front half" of the dome screen.
The neutral value for the head tilt map is a 50% grey color in the RGB image.
turn_map.png
The turn map image is used to take care of the stereoscopic effect at the zenith area directly above the viewers head. The texture map removes a swirl effect that would be present without the turn control setting.
The turn map can be used to take care of the area 180 degrees behind the viewer where the stereoscopic effect would be reversed if the viewer rotated their head to look at the back of the fulldome screen.
It is also is used to control the lens shaders panoramic stereo rendering mode where you can keep the stereoscopic orientation of a fisheye rendering facing forwards in the pole region.