540 likes | 748 Views
3D Modeling Essentials. Introductio n To 3D Modeling. George Atanasov . Telerik Corporation. www.telerik.com. What is 3D Modeling?. 3D Modeling process Representing any 3 dimensional surface Automatic or Manual. What is 3D Model?. The product is called 3D model 3D model can be:
E N D
3D Modeling Essentials Introduction To 3D Modeling George Atanasov Telerik Corporation www.telerik.com
What is 3D Modeling? • 3D Modeling process • Representing any 3 dimensional surface • Automatic or Manual
What is 3D Model? • The product is called 3D model • 3D model can be: • Rendered to 2D image • Printed to realistic object with 3D printer • Used in 3D games with real-time rendering
Splines & NURBS • Vector design is better for industrial goals • Hands of the Craftsman vs. CPU Lathe
Polygon Mesh Objects • Polyhedral object • Best for games and physical simulations
Polygon Mesh Objects • Polygon mesh sub-object level • Vertex • Edge • Face • Polygon
Mesh vs. Spline • Why Mesh is better for game development? • More calculations == less FPS • Nowadays GPUs are designed to perform faster with VBOs (Vertex Buffer Objects) • Mesh objects can be easily represented in VBO • The absolute accuracy of the objects is not basic goal in the Games • In game developing the basic goal is to create the best possible representation of an object with the least possible resources
The 3D Scene • Three dimensional coordinate system • Represents uniquely all the points in it by three parameters – values for each axis • Contain sub-coordinate systems • Each object has his own local coordinate system
High Poly Modeling Explaining High-Poly Design
High Poly Modeling • We can understand the idea of high-poly modeling just by its name • The more triangles in the mesh, the more detailed the object is • Final renders are appropriate for • Commercials • Magazines • 3D Movies
Low Poly Modeling Explaining Low-Poly Design
Low Poly Meshes • Low poly mesh is a mesh which has small amount of polygons • Commonly used in real-time applications • In theory polygons can have infinite number of sides, but in 3D graphics they are broken down into triangles
Why Low Poly? • Why we need to create low-poly models when there is so many smooth modifiers? • In general the more triangles in a mesh the more • detailed the object is • computationally intensive it is to display • To decrease render time it is better to use low poly models
The Polygon Budget • A combination of game engine and the computer being used defines the polygon budget • It is equal to the number of polygons which can appear in a scene and still be rendered with acceptable frame rate • It varies depending on the • speed of the render engine • the amount of polygons • The speed of the hardware
Low Poly As a Relative Term • There is no defined threshold for a mesh to be low poly • This term is relative and its definition depends on other factors: • The time in when the meshes were designed and for what • The detail required in the final mesh • The shape and properties of the object
Low Poly – Future vs. Past • Super Mario 2 – 1996 • In 1996 rendering an objects created by 240 polygons was a huge success • All the environment is created by textured extremely low polygon objects • Crysis 2 – 2011 • At 2011 rendering objects created by 24 000 polygons is not a big deal • The environment is created by averagely resolute objects
Appearance • Low poly objects do not always have to look bad • You can “lie” the viewer that the object has better resolution with techniques such as • Normal mapping • Bump mapping • Etc.
Smoothing Smoothing techniques
Smoothing • There are many methods to create a smooth objects • Normal smoothing • Mesh smoothing • Etc. • It is important to understand how to use each one of them • You have to pick the best for your goals
Normal Smoothing • Normal smoothing affects only the way that the light is reflected by the objects surface • That is better for games, because the triangle count stays the same • Ends of the object remain edgy • Performs better on dark colors
Mesh Smoothing • Mesh smoothing affects directly the geometry of the object • Can be used many times on the same objects • Iteration value • With each iteration increase, the resolution of the object increases by square
Lights Understanding Lightning in 3D
Why We Need Lightning? • Modeling the 3D object is just a little part of the whole design process • The light makes the object to look as 3D object
How the Light Works? • For full realistic light simulation you would need a “NASA” computer • The lighting in 3D graphics is not exact representation of the real light • In most 3D engines the light appearance is decayed to separate effects independent of each other
Abstract Types Of Lights • The light is composed by several abstract components • Diffuse, Ambient, Specular, Emissive, Reflection, Refraction • Each light component can have its own color • It is important to understand how to deal with each type of them • And it is more than important to understand how the real light affects the objects
Ambient Light • When sun ray hits an object it reflects from it • The ambient light is the emission of all light sources • The result is averagely brightening whole object • 3D object with only ambient light channel applied to it looks 2D
Diffuse Light • Diffuse light represents a directional light casted by a light source • It can be explained as a light from light bulb placed on specific location in the space • A diffuse light of red color, coming from the left of a black object defining its 3D shape
Diffuse light • For more realistic result we can apply both diffuse and ambient light channels • The diffuse light represents a light from a light bulb and flashes the front side of the object • The ambient light brightens the entire object
Specular Light • The specular light channel represents the brightest area of the object (the highlight area) • The position and the amount of specular highlight is depends on • The viewers position • The angle between the viewer and the source
Emissive Light • Emissive light works a little different than the previously explained before types of lights • It is responsible for the object material ability to absorb or reflect light • Below is the result of object emitting green light with red light source applied
Reflections • The use of reflections helps to create more realistic objects • Remember... You would not see the reflection effect if you don’t have another objects to reflect • Reflection looks better on round objects • Do not overdo with the reflection effect • Reflection mapping saves time
Refractions • The refraction property defines how much light goes through the object • In simple language it controls the opacity of the object • Refraction color #000000 == full opacity • Refraction color #FFFFFF == full transparency
Textures Texturing Essentials
Textures? • Textures are just simple raster pictures • JPEG • PNG • TGA • GIF • TIFF • Widely used in 3D game modeling
Why To Use Them? • If you are developing a car racing game you do not need to model all the details on the buildings behind • By texturing your object you can add a lot of details on the model without adding any more resolution to it • For example you can use a texture of window instead of modeling it
Texturing Methods • There are several ways to texturize an object • Which one is better depends on the object which is going to be texturized • In game developing process the basic texturing methods are • UVW Mapping • Tiling • UVW Unwrapping
What is Tiled Texture • Tiling is another trick which saves a lot of resources • To understand it, imagine that you have to represent the facade of a huge building by texturing • The idiotic way is to draw a huge texture with a lot and the same windows in it • The right way is to draw a texture with only one window on it and multiply it
Texture Optimization Tricks • Creating details with textures instead of polygons saves render time • Do not flood your 3D scene with huge amount of textures • Do not use bigger textures than you need • Manage balance between quality and size • When it is possible use texture modulation
Texture Modulation • Useful for level editing (creating environment) • You want to model brown roof tile and the same ones, but in different colors • Use white (or bright) roof tile texture and modulate it with the color of its object • You can create many different looking models with the use of one and the same resource
Use Transparency • OK… We have to create a metal fence • But how many polygons we need? • First way is to create it as a polygon mesh • 100 000 polygons for 1 meter wide fence ?!? • The trick to do that is to use a texture of metal fence with transparency at the empty spaces • 2 polygons and the result looks the same
UV(W) Mapping • Projects a texture map to 3D object • Assigns pixels of the image on the polygons • Allows you to texturize more complex shapes
Unwarp UVW • A very useful technique for texturing game characters and other complex objects
Tools & Software What Software To Use
Define Your Goals • Your goals are ? • Making super cool 3D game models • Making very detailed models for commercials, magazine covers, movies, etc. • Making 3D models for an industrial goals • Level editing for games • You are learning
Comers & Games • Appropriate software • 3D Studio Max, Maya • Blender, Google SkatchUp • Cinema 4D • Inappropriate software • SolidWorks • AutoCAD, ArchiCAD
Industrial • Appropriate software • SolidWorks • AutoCAD, Civil 3D • ArchiCAD • Inappropriate software • 3Ds Max, Maya
Level Editing • Appropriate software • Civil 3D • 3Ds Max • Blender • Inappropriate • SolidWorks, AutoCAD, ArchiCAD • 3Ds Max • Blender
3D Modeling Essentials ? ? Questions? ? ? ? ? ? ? ? ? ?