CSE 334 Research Paper. Name: Gene Chan. Date: Title: Constructing a physical figure into a 3d computer model.

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1 CSE 334 Research Paper Name: Gene Chan Date: Title: Constructing a physical figure into a 3d computer model. Overview: Recreating a realistic 3d model from an existing real world object can be very challenging. This paper will show an easy way to model a complicated object in 3d, with little artistic background. The follow is a list of software and equipment that I will be using in this tutorial. Adobe PhotoShop 7.0, Macro Media Free Hand MX, Eovia Carrara 3, a large green cloth back drop, and a digital camera with tri pod. Process: The figure in my example will be model robot that consists of many individual parts. You can use any object you want to model, but since my robot has many symmetric pieces such as the arms and legs wings and swords, I would only have to model a single arm, leg. During the modeling phase I can invert the parts of the model in Carrara to get a symmetric duplicate. This would save me 40% of the modeling time if I where to model each pieces separately. Start by disassembling your object and place each part in front of a green back drop. With a Digital Camera take pictures of the front, back, top bottom right and left of the object. You only need cross sections of the object but it helps to have as much information about the object to apply color and addition detail that simple cross sections can not provide. Later on you can use the extra pictures and apply them to your model as textures maps. Try to take the clearest picture for your cross sections. Blurry pictures will cause a lot of problems during the modeling phase.

2 Take your pictures to PhotoShop, with the magic wand tool and the eraser tool, remove the green back drop. Save the new image in a different folder. With the magic wand tool select your object and paint the whole selection black with the paint bucket tool to black out your cross section. Save your image under a different folder, and repeat the process for each picture. Magic Wand Eraser Paint Bucket The next step is to convert each blacked out cross section to an ai file. In Free Hand, open any of the blacked out pictures that you just created from PhotoShop. Then trace the object with Trace button. Export the file as an ai file to a different folder. Repeat each step for each blacked out object. It is important to Export your newly trace object and not Save As. Saving the object will not create an ai file.

3 Trace Tool Open Carrara and create a new project. Create a new spline object in any of the windows. From the modeling room import one of the ai files exported by FreeHand. In the model room extrude the cross section to create the correct proportion of your object. Its important to start with the center piece of your model. In my example I start with the torso. Every other piece that you attach to your object in the assembly room will be in proportion to the center piece. Start attaching each of your cross section as you created them. Once you have a good idea of what your current piece will look like, start removing unneeded cross section and add other primitive objects to fill out empty areas for a better look. You can also try extruding a whole cross section and shape it for a desired look Repeat this step for each piece of your model and build out a ruff frame work for your project.

4 Edit, To duplicate groups or a single part of your model, select the part or group(s), click edit and select duplicate or duplicate with symmetry. Duplicate will create a new copy right on top of the old object. You will not see the new object until you move it Lower Body Group Full Figure Group that includes all th sub Groups and an parts that don t belong in a group Upper Body Gro Right Arm Group By now you should have many parts completed in the assembly room. The next step is to move all the hot points of your object. Set your x y z coordinates of the hot point on the area each of your object to where you want it to rotate. The next step is to start grouping your pieces into some order. For example, group all the parts for the a upper body together ( head, torso,right arm, left arm ). The lower body as (pelvis, right leg, left leg). Its also a good idea to create groups like the left arm, right arm, lower right arm, lower left arm, left leg. This will allow you move you several parts as a whole, like raising your arm without moving the rest of the object. To create a Group go to Edit and select Create Group and drag each part in the properties tray into the group, or select several body parts while holding the shift key and go to Edit and select create Group. Remember to name your group. The next step is to start adding each part of your object into some hierarchy. Select your group and hold the mouse button and drag the group to the parent group. For example the hand is the child of the lower arm, the lower arm is the child of the upper arm, the upper arm is the child of the left or right arm, which in turn the child of the torso. Repeat this step until your root object is created and all the parts of your model is under the root. It is important to set your hot points before creating the hierarchy. If you change the hot points after creating the hierarchy all of the child objects of the current object will adjust to follow the current object s hot point. The next step is to set your motion of constrains of each part of your model. In the motion tab in the properties tray you can set your Motion to explicit or any other options. I personally like the custom option. From there you can lock a piece of your model from being accidentally removed from the whole model.

5 The next step is to add color to all of your pieces. This allows you see and select each part of your model easier then the default tan color that Carrara forces you to use. To start moving your model to different poses use the 4 window option and view your model from the front, top, left or right and Camera 1. This is the best way to rotate parts of your model with symmetry and allow you to see the finish product. Important, when rotating or moving your group (ex Left Arm) you must collapse the left arm group to start moving the Left Arm group. If you do not collapse the children objects of the current group you may not be able to move the current group. This problem exists in Carrara 3 but is fixed in Carrara 4. Summary: Finally add and nice background and pose your model in any position you want. Set your camera in any location and render the current frame in the render room. Bibliography: A tutorial that I use to help my build the hierarchy of my model can be found in Writen by Jack Whitney.