An image sequence is a series of still images that have been rendered or photographed from multiple different angles in a full 360 degree panning and or tilting. With panning you will render your image from left to right and with your tilting you will render your image from the bottom to the top.
Equipment required
Your capturing equipment must consist of one of the following:
a camera (digital or film)
3D Software (3D studio max, lightwave, maya, or any other of your choice)
The following are optional extra's when using a camera:
light
a backdrop
turntable or pedestal (to rotate the object)
a hot glue gun
A digital camera that can take still frames and has USB cable connector is favorable for this work due to the fact that an image sequence can consume a lot of shots. That is why a digital camera which is able to download images to your computer whilst shooting works best.
A set of lights to illuminate the object along with a backdrop may be used for your shoot.
If you decide to use a backdrop:
With a black backdrop you must use low lighting
with a white backdrop you must use hot lighting
This is for the background to be completely black or white and to make it easier to edit out the background later on.
If you decide to use a pedestal or turntable you must ensure that it is stable to swing and easy to rotate in increments of 5-10 degrees.
If you plan to shoot an object from below, you will need a pedestal which is preferably thin and black. The hot glue gun will allow you to position an object in any position you desire and require it to stay put.
When rendering a single layer object movie, you can use a tripod to position your camera, but make sure it’s sturdy so that it does not jiggle or move while shooting.
With a multiple layer image sequence, you can use a rig that will rotate the camera in a precise arc.
It will ultimately depend on you as to how you choose to render your images and what equipment works best for you. This can only be perfected through trial and error.
Image sequencing
Calculating the pan angle:
To calculate the angle of pan rotation between images, you will need to divide 360 degrees by the amount of images required per layer. For example if you decide to render 20 images per layer you need to divide 360 by 20 which will give you 18 degree intervals between each image panning rotation. The best scenario is to render 36 images per layer - therefore 360 divided by 36 will give you a 10 degree interval between each image.
Calculating the tilt angle(If tilt is required): To calculate the angle of tilt rotation between layers you will need to divide 180 degrees by the number of layers required. For example if you decide to use 18 layers you will need to divide 180 degrees by 18 which will give you a 10 degree tilt angle interval between layers.
Say for example you only want to tilt your object from the front to the top you will need to divide 90 degrees by 9 layers which will give you a 10 degree tilt angle interval between layers.
Once you have established your pan and tilt angles you should start capturing your images from the front most point of your object from left to right for panning and bottom to top for tilting at the decided amount of panning and tilting intervals, therefore giving you your required images for your full image rendering. The amount of images rendered will be the amount of panning images multiplied by the amount of tilting layers. For example if you have 36 panning images and 18 tilting layers then you would multiply 36 by 18 and you would end up with a total of 648 images.
Note: It is very important that you capture your images from left to right in a counter clockwise position for your panning view and in multi layering from the bottom upwards for your tilting views.
1. Single Layer Sequencing:
Single layer sequencing is rather simple in the sense that you need only to capture your object in one layer instead of multiple layers. In a single layer image you will be capturing images for 360 degrees panning view from left to right only.
You need to establish the centre most point of your object and begin to capture it in a 360 degree counter clockwise panning view every 10 degrees, therefore you will be capturing your object in 36 images all around for one layer only. You will need to capture your series of images by keeping your camera at precisely the same alignment level with your object, while you pan the object from left to right around it's center point.
Once you have captured your images you should then either - depending on your choice of equipment do the following:
If a film camera was used you need to convert your images into CD format or scan your images to your PC and retouch your images as per explained below(These methods are applicable for digital imaging as well):
You need to retouch each image using your favorite image editing program for example, Photoshop or any other similar program. This will be applicable to both digital capturing as well as for film capturing.
Once you have edited out your pedestal and all other equipment you need to apply a background color that will work best for your object (A transparent background works best), you need to compress you image into a .JPEG image. It is important to note that you must compress your images into one format.
In flash 8 .JPEG, .GIF and .PNG formats are compatible as options to save your images. For Flash 7 only .JPEG format is supported.
Once you have accomplished this you will need to save your images into the .xml file so that you can load them for your object movie.
2. Multi Layer Sequencing:
The same applies to Multi Layer Sequencing as to Single Layer Sequencing except that you will need to render 36 images per required amount of layers in full panning and tilting rotation:
You will have to render 36 images in 10 degree intervals for 18 layers but with the added capturing of tilting view. Thus you will need to capture a series of images in multiple layers by keeping your camera at precisely the same alignment level for each layer and use a centre poi
nt that can be used for each layer to ensure that your object will be captured correctly around this point while you rotate the object. In other words you will be repeating the capturing process with the camera at different vertical positions, but with the exact same alignment, rotating the object at exactly the same positions per layer.
With Multi Layer Sequencing you have to remember that there are more images to capture and with this comes the added effort of ensuring that the object which is captured has more to be edited out with an imaging editor ie. Photoshop or similar programs than with a single layer object due only to the fact that there are more angles which are being captured.
Your object will need to be fully rotatable and tiltable by your capturing of the object for the component usage.
This can be obtained by capturing your object as per your desired amount of pan and tilt angle which you calculated giving you 360 degrees rotation and tilting captured view.
Once you have saved your images you will need to insert these images into your .xml file.
In short your image sequencing is the capturing of your object as per your desired method and calculation of tilt and panning angle and then editing out all which is not needed in the view of your final product of the object. After this it is the correct method of saving these images to ensure that they are available to the necessary files. You will need to acquire all of the above and apply them to give you your end product which is an object which can be viewed in full rotation in virtual motion as if you were holding it yourself.
Important: The amount of layers captured, the starting and ending point of your capturing in panning and tilt, and the increments between images are completely under the control of the user.