SE 313 – Computer Graphics Lecture 4: Represeting 3D Models Lecturer: Gazihan Alankuş Please look at the last three slides for assignments (marked with TODO)

Quiz Turn off monitors Take out a piece of paper and a pen/pencil 5 minutes

Our Goal Understand how 3D models are represented in computers. Supplement this knowledge with practice in Blender

3D Models A 3D model encapsulates the geometrical and visual properties of an object in a virtual world. – Can be used for rendering (taking a virtual photograph) – Can be used for other purposes as well (collision detection, physics calculations, etc.)

How are 3D Models Represented? Geometry Visuals

Elements of a 3D Model Geometrical elements – Vertices – Edges – Faces – Normals Visual elements – Materials – Textures – UV maps

Geometrical Elements Vertices Edges Faces Normals Demonstrations in Blender

Geometrical Elements Vertices Edges Faces Normals How they are represented in Blender: 5/blender-25-python-printing-vertex.html 5/blender-25-python-printing-vertex.html

Visual Elements Materials Textures UV maps Demonstrations in Blender

Visual Elements Materials Textures UV maps How to texture with UV maps in Blender – discovering-blender-part-3-applying-uv-mapping/ discovering-blender-part-3-applying-uv-mapping/ –

Basic Illumination Materials Lights Normals – Regular normals Using edges and the right hand rule – “Fake” normals Smooth shading

Lab assignment Part 1 – Start with a cube. Create a tower with three segments, like in the picture to the right. Part 2 – Mark its seams appropriately and unwrap it so that it unwraps like the image to the right. (You can mark seam around the top square, and vertically on each side. Then clear seam on one of the edges on the top) Part 3 – Draw a texture for it in a creative way. Random scribbles will not be accepted. Show the texture in the 3D view as well as render the object with the texture on

Project Ideas Creating 3D models of a game An interesting 3D problem that a game has and a solution to it A short movie An interactive 3D experience in Unity requiring interesting calculations

TODO: Projects Form project groups of 2-3 people. Come up with a project idea One person in your group should send the list of students and a one-page project idea proposal – Send it to and cc it to – Use the subject “SE 313 Project Group” Due November 2 nd (as next week is holiday)

TODO: Homework 4 (deliverable) Start with the first letter of your name that you created last week. (Ask for a letter model from the assistant if you did not submit last week’s homework) Unwrap it (re-watch the video on slide #10 if you get lost). The creases should be hidden as much as possible. Choose one of these themes: fire, sea, grass, soil Texture it with the theme you chose. The model should give us the feeling of the chosen theme when we look at it. The texture should look continuous no matter how we turn the object. Majority of your grade will be on the quality of your texturing. The texture should be visible in the 3D view as well as when the object is rendered. Submit the rendered image and the.blend file, just like you did last week. Due November 2 nd (as next week is holiday)