Maya nCloth

Maya nCloth - Presentation in MAAC Tech Meet (East)2010 by Abhijit Adhikari. This was recognised as best presentation from MAAC East Zone. This presentation was highly appreciated and described as model session by Abir Aich(Associate Director-Academics,MAAC), Sameer Shanishchar (Asst. Director-Academics,MAAC) and Umesh Patel(Asst. Director-Academics,MAAC) for budding faculties of this field.

Maya nCloth - Part1 out of 4



Maya nCloth - Part2 out of 4



Maya nCloth - Part3 out of 4



Maya nCloth - Part4 out of 4

What is Rotoscopy(Part III):

Note:
Footage for_roto_part_III_and_IV, you can download the original uncompressed footage from "Rapidshare" in two different formats. If you like to use image sequence, you can convert the .mov file to TGA format using any editing/compositing/video converter software. Due to file size, I am not uploading TGA format in rapidshare.

http://rapidshare.com/files/449243843/MP4_for_roto_part_III_and_IV.mp4
http://rapidshare.com/files/449250511/MOV_for_roto_part_III_and_IV.mov



To make a cut-out or matte of any character or object from a scene we use rotoscopy. Rotoscopy is also useful for image enhancement; like Color correction, color change, gradation etc. Once the animated matte is developed for any part of the scene through rotoscopy, now you can use it for different purpose. For example: In this scene if you like to create matte for the character, chair and table to change the BG I am creating 8 polygon shapes. How many polygon shapes you have to create, that totally depends on requirement of compositing section, and it will be designed by the TL or Production Head. You can also use combined technique of keying and rotoscopy together. But the keying process is not useful for Stereoscopy conversation (I shall describe further). In this example I shall only use polygon shape.
Before starting the creation of polygon shape, always play the footage several times to get the movement details of character/objects, due to camera movement any object will change the shape, in particular scene. In this example camera is fixed, so one polygon shape is good enough to cut the Table from scene. No animation is required for this shape also. But due to the activities of character, chair is moving, so I need animated polygon shape for character and chair both. Now, maximum movements are in right hand of the character. But in this example I do not required a separate polygon shape for right hand, because its moving inside of body line in front of camera. So in that case nothing to worry due to the maximum movement of right hand, it will consider inside of same polygon shape which I shall create for body. But remember, it will be complicated when I shall use the same footage for stereoscopy conversation (I shall describe it in my next article).

Create all the roto shapes one by. In this example most of the shapes was created at frame number one. And animated in an interval of 16 frames. Check the image bellow, key interval for roto shape 1 in stage 1.

In next step you have to animate the shape in a key interval of 8 frames. Check the image bellow, key interval for roto shape 1 after stage 2.

In this way I animate all the roto shapes. After stage 5 I found that, I am able to complete the animation of all roto shapes for each and every frame. If you follow the same procedure, within a very short span of time you can animate all the roto shapes for every frame with highest amount of perfection.
Stage 3:

Stage 4:

After stage 4, I found that, if I continue the same process; after stage the polygon shape will animate for each every frame perfectly. Sometime it may happen that, the animation is not required for each and every frame. But few production houses like to use frame by frame animation and this habit is also useful for stereoscopy movie conversation. One more thing, in this example I am using soft edge for the polygon shape (value: 0.0005) but in case of stereoscopy movie conversation you can’t use soft edge, this pipeline needs précised polygon shape. When you are using roto shape for hair, you have to remember that hairstyle is important for a character; production may ask you to roto all the hair lines. If production is not asking for that, then you have to maintain the shape of the hair which is carrying the characterization of the character. In black n white format if you get the character that it is actually, then your rotoscopy is ok.
Rotoscopy is a time killing process and needs lots of passions to complete rotoscopy for any complicated scene. For a vfx composition, rotoscopy is must; so a compositor can’t avoid rotoscopy. But smart compositor use different techniques to create animated mask for a scene. Like combination of color suppress, keying, 2D tracking etc. Production houses are using few software dedicated for rotoscopy like “Silhouette”. If you know the rotoscopy process in “Fusion”, “Shake”, “Nuke” etc you can upgrade yourself in rotoscopy, within a very short span of time for any new software.