GB2317577A

GB2317577A - Simulated animation of models

Info

Publication number: GB2317577A
Application number: GB9620172A
Authority: GB
Inventors: Richard Langton Gregory
Original assignee: Individual
Current assignee: Individual
Priority date: 1996-09-25
Filing date: 1996-09-25
Publication date: 1998-04-01
Anticipated expiration: 2016-09-25
Also published as: GB9620172D0; GB2317577B

Abstract

The model according to the invention comprises an optically conductive substrate 1 including an array 3 of optical fibres 4 which transmit in coherent fashion a moving image from a screen 8 (e.g. a conventional television or VDU screen) to a translucent or transparent mask 2 defining the contours and other characteristics of the face. An observer views the moving image emitted from the substrate through the mask 2. Provided that the moving image corresponds with the correct facial feature(s) of the mask 2 (e.g. the mouth part of the moving image is aligned with the mouth of the mask), an illusion of animation of the facial feature(s) is created. A model human or animal face is provided, which is capable of displaying simulated animation of facial features without (as hitherto) external projection of moving optical images onto the model.

Description

IMPROVEMENTS RELATING TO SIXtILATED ANIMATION OF MODELS The present invention relates to simulated animation of models, more particularly to models of human and animal faces capable of displaying simulated animation of facial features.

It is known that a model face can be given the appearance of animation of facial features by externally projecting onto the surface of the model from a remote projector a cinematographic image of a moving facial part, such as a mouth, eyelid, eyeball etc. Provided that the projected image is superimposed onto the corresponding location on the surface, namely for the mouth the mouth region, or for the eyelid or eyeball the eye region, this known technique provides reasonable simulated animation. Even though the actual surface contours of the model are static, the moving image deceives the observer's eye sufficiently to create an illusion of animation.

The known technique suffers, however, from a number of disadvantages.

Firstly, it is generally impossible for the model to be moved mechanically while the image projection takes place, as this would require corresponding movement of the remote projector system.

Secondly, the illusion can be destroyed if the projection line onto the model is blocked, e.g. by a person walking between the projector and the model.

Thirdly, the projector is noisy and requires careful operation, monitoring and control. The initial alignment of the projected image onto the model also requires a certain degree of skill and expertise.

Primarily because of the above disadvantages, the known technique for providing simulated animation of models has generally been used only in the recording studio environment, in which the simulated animated models are video-recorded, with later sound dubbing if desired.

In principle, however, simulated animated models could be more widely used, with synchronised simultaneous sound effects, particularly speech, if an animation technique could be found which overcomes the disadvantages.

The present invention aims to go at least some way towards realising this potential.

According to a first aspect of the invention, therefore, there is provided a model human or animal face capable of displaying simulated animation of facial features, comprising: an optically conductive substrate including an array of elongate optical waveguides having a light input surface at a first end of the substrate and a light output surface at a second end of the substrate and capable of transmitting an optical image from the first to the second ends and emitting the image from the substrate at the second end thereof; an at least partially transparent face surface in optical communication with the second end of the substrate and provided with surface contours, and optionally surface attachments, defining features of a human or animal face; and a screen in optical communication with the first end of the substrate and adapted to emit to the substrate a moving optical image which, when viewed by an observer at the second end of the substrate through the face surface, creates to the observer an illusion of animation of at least some of the said facial features.

The term '1animation" includes all forms of temporal change ('1movement") of an image. Thus, for example, changes of shape, position, dimension, colour, pattern, configuration, focus, definition, brightness, contrast or combinations thereof, will all be considered and understood as examples of animation.

The screen can be any conventional screen capable of emitting an animated optical image. Thus, for example, conventional television or visual display unit (VDU) screens, liquid crystal display (LCD) screens and rear projection screens (e.g. video or cinematographic projector screens) may all be used, with conventional associated image-generation systems.

The array of optical waveguides is suitably constructed of any conventional lightguide materials, e.g. optical fibres, and arranged so that registration (coherency) of the image inputted from the screen at the light input surface of the array is maintained when the image is emitted at the light output surface of the array to be viewed through the face surface of the model.

The waveguides may be made from any transparent solid material, such as transparent polymers, glass and fused silica. The material should have mechanical and optical stability at typical operating temperatures of the model.

Glass may be generally convenient. However, transparent polymers have the advantage of structural flexibility and relative softness, which allows the substrate to be formed in a unit and the second end of the substrate shaped, e.g. by moulding or cutting, to provide the desired surface contours defining features of the human or animal face.

The polymer may, for example, be selected from polymers including polymethylmethacrylate, polycarbonate, polyester, polystyrene and polymers formed by photopolymerisation of acrylate monomer mixtures composed of urethane acrylates and methacrylates, ester acrylates and methacrylates, epoxy acrylates and methacrylates, (poly)ethylene glycol acrylates and methacrylates and vinyl-containing organic monomers. Suitable examples of monomers include methyl methacrylate, n-butyl acrylate, 2-ethylhexyl acrylate, isodecyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, cyclohexyl acrylate, 1,4-butanediol diacrylate, ethoxylated bisphenol A diacrylate, neopentylglycol diacrylate, diethyleneglycol diacrylate, diethylene glycol dimethacrylate, 1,6hexanediol diacrylate, trimethylol propane triacrylate, pentaerythritol triacrylate and pentaerythritol tetraacrylate. Especially useful are mixtures in which at least one monomer is a multifunctional monomer such as diacrylate or triacrylate, as these will produce a network of crosslinks within the reacted photopolymer.

The individual optical waveguides of the array are preferably in the form of fibres or rods which transmit small portions of the image emitted on the screen. The individual waveguides may, if desired, be retained in position by means of an interstitial bonding component such as a solid polymeric resin. It is essential that any interstitial bonding component has a lower index of refraction than the material of the individual waveguides.

Light rays which enter an individual waveguide through the light input surface and thereafter are incident on the side surfaces of the waveguides at angles greater than the critical angle (as defined by Snell's Law) will undergo one or more total internal reflections from the side surfaces and, in most cases, will emerge from the waveguide through the light output surface. A few light rays may pass through the side surfaces or be reflected back to the light input surface. However, this percentage loss will be negligible or at least tolerable, without substantially affecting definition and brightness of the transmitted image.

The substrate preferably includes sufficient optical waveguides to maintain optical communication with the face surface over substantially the full area of the face surface.

The face surface of the model has surface contours which define at least part of a human or animal face, preferably the whole face. The surface is formed in a translucent or transparent material, suitably having an appearance similar to the skin or hide of the human or animal being represented. The face surface contours may be generally convex, in the manner of a live face, or may be inverted into a generally concave arrangement when viewed from the front, in the manner of the reverse surface of a moulded mask. It is known that an inverted (concave) face can still appear lifelike by optical illusion. Any surface attachments of the face surface may suitably be selected from hair, clothing and personal accessories such as jewellery or spectacles. In the case of a human model, the facial features of a particular individual can be created.

The material of the face surface may be a separatelyformed thin translucent or transparent mask, having a front and a rear mask surface, with the light output surface of the array of optical waveguides at the second end of the substrate abutting the rear mask surface at locations corresponding to those facial features for which simulation of animation is required, e.g. in at least the regions of the mouth, eyes, eyelids, chin and cheeks of the mask. The light output surface of the array of optical waveguides at the second end of the substrate is suitably contoured to correspond to the rear mask surface and is suitably adhered thereto by an optically transparent bonding agent such as a conventional transparent polymeric resin. For example, if the mask is of glass and the waveguides are formed by photocrosslinking acrylate monomer materials, then the parts can be bonded by reacting the glass rear surface of the mask with certain types of silane compounds such as 3-(trimethoxysilyl)propyl methacrylate or 3acryloxypropyl trichlorosilane.

Alternatively, a separately-formed mask can be dispensed with, and in appropriate cases the face surface can be formed on the second end of the substrate, e.g. by cutting or moulding the desired surface contours directly onto a substrate block including the array of optical waveguides.

The screen can be bonded releasably or permanently to the light input surface of the array of optical waveguides at the first end of the substrate, as desired. Such bonding is achieved using conventional optically transparent adhesives. Alternatively, the screen and the substrate can be held in juxtaposition by a mechanical fixation system of conventional construction. In that event, it is preferred that the screen and-the light input surface of the array of waveguides touch each other, and/or that other conventional measures are taken to avoid light leakage between the screen and the light input surface of the array of waveguides.

It is preferred that the screen and associated imagegeneration system is small enough to be mounted within a simulated head. The whole model face and head assembly can suitably be mounted on a motor-driven movable support structure of conventional construction, the support structure being suitably hidden under clothing or simulated skin or hair. In this way, the head can be made to move, for added realism.

In use, the moving images are generated in conventional manner at the screen, preferably with synchronised sound played through electrical speakers in conventional manner. The light emitted from the screen travels through the waveguide array and is emitted as a corresponding coherent image through the facial features of the face surface of the model, on which the moving image is thus observed when the model is viewed from the front. This creates to an observer an illusion of animation of the facial features.

It is possible to incorporate actual physical movement of some of the facial features of the model, if desired for added realism. This can be accomplished by conventional mechanical apparatus built into the model face and operated, for example, by computer controlled servo motors. Thus, for example, mouth and eyelid parts can be made mechanically movable if desired, optionally in addition to simulated animation provided by the present invention.

The actual physical movement of the head and/or individual facial features can be made interactive by means of suitable known controlling software and optical and/or audio systems, so that the movement is triggered and influenced by external events.

To construct the model according to the invention a mould of the desired face is typically prepared initially. It can be quite a crude representation, as many of the details that the eye uses to recognise a face will be imparted by the surface attachments and/or the transmitted optical images. The contours of the mould will suitably be quite rounded.

The mould is then used to cast the translucent or transparent mask, e.g. in a slightly diffusing plastic.

Vacuum forming may conveniently be used for this purpose.

To the rear mask surface the optically conductive substrate is then applied, suitably by putting a bundle of optical fibres (e.g. glass fibres) into the rear of the mask, preferably exactly filling it. One can check that the optical fibres are correctly positioned by looking through the mask from the front. The glass fibres, which may or may not be embedded in an interstitial bonding component, are secured to the mask, suitably by a transparent glue, and the first (screen communicating) end of the substrate then formed by cutting the bundle off to form a first surface. For a flat screen (such as a liquid crystal display screen), the first surface will desirably be substantially flat; for a contoured or curved screen (such as a cathode ray tube screen (CRT screen)), the first surface will desirably be correspondingly contoured or curved.

It is believed that a single model face form (or a small set of face forms, for example defining different ages, genders or racial groupings), will suffice for animating a wide range of specific faces, e.g. of historical or famous people. For entertainment purposes, a child's moving face could be recorded by video recorder and then viewed on the face surface of the model according to the invention.

For further understanding of the invention, and to show how the same may be put into effect, an embodiment will now be described, purely by way of example and without limitation, with reference to the accompanying drawings, in which Figure 1 shows in perspective front view a model head of a famous person, namely Michael Faraday (17911867); Figure 2 shows the model of Figure 1 omitting the front mask for clarity; and Figure 3 shows the model of Figure 1 in vertical cross-section.

Referring to the Figures, there is shown a model of the head of Michael Faraday, capable of displaying simulated animation of facial features, namely mouth and eyes.

The facial features are formed as a thin translucent plastic mask portion 2 having forward surface contours which define the features of Faraday's face. The mask is moulded from a polymeric material and treated with conventional colouring, cosmetic and texturing procedures to provide a lifelike representation, for example in the manner of a waxwork model.

Immediately behind, and in optical communication with, the mask 2 lies an array 3 of optical fibres 4 constituting an optically conductive substrate portion 1 of the model. The optical fibres may be of glass or a suitable transparent polymer. The optical fibres are conveniently (but not essentially) embedded in substantially parallel alignment in a polymeric resin bonding matrix of lower index of refraction than the material of the fibres. In this way, the optically conductive substrate 1 transmits a coherent image from a first (light input) end 5 to a second (light output) end 6 of the substrate and the array along the length of the optical fibres 4.

In an alternative but less preferred embodiment (not shown) the substrate 1 can have regions of arrays 3 of optical fibres, corresponding to the regions for which animation of facial features is required, separated by regions which do not include optical fibres (and may even be opaque), corresponding to the regions for which animation of facial features is not required.

It is important that the substrate 1 and mask 2 are in good optical communication, so that an image emitted at the second end 6 of the substrate can be viewed through the mask 2 by an observer from the front of the model.

The moving images of facial features, emitted at the second end 6 of the substrate 1 and viewed through the corresponding facial features of the mask 2, are the basis for the optical illusion of simulated animation created by the invention. The second end 6 of the substrate 1 is therefore contoured to correspond with the inner contours of the mask 2 at its rearward surface 7, and the parts 1 and 2 are bonded together with a conventional optically transparent adhesive (not shown) The moving images of facial features transmitted along the optical fibres are created at a conventional VDU screen 8 which is in optical communication with the first end 5 of the substrate 1. The images are created by conventional software controlled electronic apparatus shown schematically as 9, connected to the VDU screen in conventional manner. The images are arranged so that, when viewed by the observer from the front of the model, having passed through the optical fibre array 3 and the mask 2, an illusion of animation of some or all of Faraday's facial features is created.

The mask and substrate assembly is detachable from the screen 8 and a set of different such assemblies is suitably provided, representing a range of famous persons, for selection as desired. A conventional mechanical fixation system 10 holds the parts firmly together, and the first end 5 of the substrate 1 is formed as a flat surface which fits closely against the screen 8, to minimise light leakage between the screen and the substrate. The' whole arrangement is suitably built into a model of the person's head at least, which could if desired be movable on a conventional electronically controlled movable supporting structure.

To construct the model, a mould (not shown) of Faraday's face (or of a face shape roughly approximating thereto) is initially prepared. The plastic mask 2 is formed in the mould by vacuum forming. The array 3 of optical fibres 4 are then stuck, by transparent glue, to the rearward surface 7 of the mask, and the optically conductive substrate 1 then formed by applying the polymeric resin and allowing it to harden to form an interstitial bonding matrix. The polymeric resin can be omitted if desired.

The array of optical fibres 4 is then cut off square to form a substantially flat surface constituting the first end 5 of the substrate which fits closely against the screen and is held in position by the mechanical fixation system 10. Surface attachments such as facial hair 11 can be adhered on-the surface of the mask 2 and the whole arrangement is housed in a model head 12 covered with head hair 13. The model is mounted on a support surface 14, which is disguised under clothing 15.

Claims

1. A model human or animal face capable of displaying simulated animation of facial features, comprising: an optically conductive substrate including of an array of elongate optical waveguides having a light input surface at a first end of the substrate and a light output surface at a second end of the substrate and capable of transmitting an optical image from the first to the second ends and emitting the image from the substrate at the second end thereof; an at least partially transparent face surface in optical communication with the second end of the substrate and provided with surface contours, and optionally surface attachments, defining features of a human or animal face; and a screen in optical communication with the first end of-the substrate and adapted to emit to the substrate a moving optical image which, when viewed by an observer at the second end of the substrate through the face surface, creates to the observer an illusion of animation of at least some of the said facial features.

2. A model face according to claim 1, in which the face surface is a translucent or transparent mask overlying and in optical communication with the second end of the substrate.

3. A model face according to claim 1, in which the face surface is formed directly in the second end of the substrate.

4. A model face according to any one of claims 1 to 3, in which the face surface is adapted to resemble the texture and contours of the face of a famous person.

5. A model face according to any one of claims 1 to 4, in which any surface attachments of the face surface are selected from hair, clothing and personal accessories such as jewellery or spectacles.

6. A model face according to any one of the preceding claims, in which the optical waveguides are glass fibres or rods.

7. A model face according to any one of claims 1 to 5, in which the optical waveguides are polymeric fibres or rods.

8. A model face according to claim 6 or 7, in which the optical waveguides are embedded in substantially parallel alignment in a bonding matrix of lower index of refraction than the material of the optical waveguides.

9. A model face according to any one of the preceding claims, in which the screen is selected from a television or VDU screen, a LCD screen and a rear projection screen, and is provided with a conventional associated imagegeneration system.

10. A model human or animal face capable of displaying simulated animation of facial features, substantially as herein described with reference to the accompanying drawings.