Camera Mapping / Projection Report Cart 434 Advance 3D Studio By Umer Usman Instructor: Stephan Menzies

3D CAMERA MAPPING / PROJECTION IN MAYA

Abstract Through my research I have learned the technique of 3D camera mapping or projection in Maya. It has enabled me to use 2D images and bring them to life using 3D mapping techniques and this techniques is quite often used in films to serve the need of displaying huge scenery, city or landscape with other compositing techniques it can truly bring images to life.

Index 1. Goal 2. Introduction 3. Learning about 3D projection • Taking Photos for Camera Projection and common issues • Finding the actual Focal Length and setting it in Maya 4. Setting up Projection or Mapping • Matching the first point of our building • Creating a basic camera rig 5. Creating our projection shader 6. Applying Camera Animation 7. Final rendering 8. Conclusion

1. Goal My goal or objective is to achieve and create •

Realistic scenes or environments within Maya in relatively short amount of time.

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Using still / 2D image to create a virtual set

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Project that image onto a low polygonal geometry to attain photorealistic results with minimal fuss

2. Introduction The objective of this project is to learn the procedure of Research and development about camera projection to create photorealistic scenes. To understand the process and technical aspects of projection to be able to create virtual photorealistic sets and to be able to use them in an effective manner. There are many things to consider before approaching this technique however they are very simple. Two things you need to know before you start using projection. • What type of image one will be using which will result in your camera animation. This has to be planned before starting on projection. • The focal length to line up your camera with the back plate. So that your geometry is synced with the back plate. After attaining all the relevant information we can start match moving our geometry with the back plate. 3. Learning about 3D projection Two things we need to consider beforehand what type of photo will be used for the end result. Taking Photos for Camera Projection and common issues You need be aware of how to take photos for the final and end result being projected and things we need to avoid and common issues that arise during this process. The picture below was used for test purposes from Digital Tutors. This photo has a clear sky, a clear outline for the building, lighting is nice, and there isn’t too much reflection in the windows. Another important consideration that this image was shot at an angle rather than front façade which enables and makes easy for us with more information about the building to build the geometry. A common rule is that any edge with more than 90 or 70 degrees turned away from the

camera causes problem because there is not enough pixel data. The image 3b was used for the final end result and it was chosen because the animation needed to be done was mainly focusing the shack rather than rotating the camera from left to right.

3a. Photo used in the testing process in project, how to take photos and avoid common issues.

3b. picture used in the final end result.

Finding the actual Focal Length and setting it in Maya The second most important thing to find is the focal length of the camera with which the picture was shot. This is extremely important because without this our geometry will not sync properly with the back plate. The focal length can be found using the Meta data that comes with the photo. All you need to do is to right click on the image > properties > detail tab. The 3C image below tells us this information. In some photos the focal length is mention for a 35mm lens in Maya. In most cases it isn’t. For this we have to do a simple calculation which is, take the focal length of the camera with this the image is shot in our case it is 24mm. Next step would be to take the camera model Nikon D80 and a quick google search to find out the crop factor or sensor size of the camera which is 1.52. We multiply 24*1.52 = 36.48 mm focal length for Maya.

3c. finding out focal length of the camera in maya

4. Setting up Projection or Mapping •

Matching the first point of our building There are two ways of setting up the projection. First method is you can setup your image plane and then start matching the geometry manually. The second method would be to find a starting point in your geometry. Referring back to image 3A above you will notice that from the left there is a clear starting point which we can choose to setup our initial position and from there on we can build the rest of the geometry and aligning perfectly with our camera.

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Creating a camera rig We can use locators from our starting point to create a camera rig based on our starting point and based on that point we can lock the camera and animate around that point. However, you are free not to do this, it won’t affect the project at all but this is just a clean way of doing a nice angled camera animation around a specific point. Refer picture 4a below.

4a. attached Camera rig around a starting point using a locator.

5. Creating our projection shader Once our geometry is finalised, now it is time to create our projection shader which consists of four nodes. Refer picture 5a. i. Surface shader (you can use any other shader like lambert as well. This shader is good because it doesn’t pick up any lightening.) ii. Projection node iii. File node (which contains our 2D image) iv. 2D/3D texture node

5a Projection node in hypershade Maya

6. Applying Camera Animation Once our projection shader is done our geometry is ready to be animated. Click the link below to see the animation. http://3dstudiocart434.wordpress.com/projection-test/

7. Final rendering Once we are satisfied with our animation results we can go ahead and render out our animated camera before that we need to set our final render settings and then we can do a batch render of our animation which will give images in sequence which are ready to be imported in after effects for our final composite. Click the link below to see the finished R&D result. http://3dstudiocart434.wordpress.com/finished-project-a/

8. Analysis At the end of the R&D I achieved the results in project A as expect. I have achieved some relatively descent projection technique however it is nowhere near the professional level and it was during the testing during 4 weeks that I found I am able to do simple geometry projection with rectangular shape building and structures and I started to notice some of my weaker points and area of where it could be improved. One of the major problems that I found was that I tried working on photos like small forest, landscapes, mountains etc. and I could not achieve creating a geometry that complex to be projected. This also includes working a small scale city which becomes very technical figuring out the angles and where to start creating the geometry. I could not find any relevant information on this since the testing and the techniques I did were only good for boxed structures, building and easy shapes. This however could not be applied onto a relatively big city projection or doing mountainous projection or other complex projection. So definitely a vast investigation is needed to be done there. Another problem I found that with problem I found that there is a limitation to animation when doing projection. In order to do a good amount of animation you need to build each and every piece of geometry in the photo to get that depth and realism.

9. Conclusion I believe my understanding is somewhat minor as this point but I would say it is an effective outcome of my research. I am able to generate relatively easy small projection scenes at this point with only boxed, rectangular structures. However, it is I wouldn’t say impossible at this point for me to able to work in large landscape scenes which I really like to achieve but I would say there is not enough information regarding this so I am only left with projection of buildings and small stuff.

10. References Illusionary imagery Comics in 3D space Still background with 3D animation Comic style

Projection in Maya #1 Projection in Maya #1 Escape Studios Tutorial http://www.the-roots.at/blog/2012/05/simple-projections-with-maya/?lang=en_us. http://www.youtube.com/watch?v=joMxwiacPEk http://www.youtube.com/watch?v=AgA_ymkPf1o