Blitz T

2. Designing an Objective-C
Framework about 3D
(to Rule Them All)
Raphael Sebbe
Twitter: @rsebbe

4. We all Enjoy Cocoa

6. Because it’s Smart & Elegant

8. Developers are Users
Keep that in mind when designing a framework

9. The Wonderful World of 3D
OpenGL Pixar’s PRMan
Direct X POV
Ogre 3Delight
Quesa Pixie
Aqsis
OSG
VL Lucille
DotC
OpenSG
LuxRender
Mental Ray
3DKit

10. What
• A framework for building 3D apps / games,
for Mac & iOS
• Common foundation for 3D
• Specialized to talk to various libs / tools
• Good Cocoa citizen

11. Conceptualizing (a bit)
App • Computer Graphics
Math
Ceed3DGL Ceed3DRenderMan ...
• 3D Data
Representation(s)
Ceed3D
• Object Graph(s)
•
GL CeedMath Foundation
Rendering Interfaces

12. Focus on Frameworks
C3Node C3Scene C3Renderer
C3Object C3RenderManRenderer
C3ProceduralObject C3PixarRenderer
C3Sphere C3AqsisRenderer
...
C3GLRenderer C3GLView
C3GeometricObject
C3Mesh
C3Geometry C3Buffer
...
C3ParametricGeometry
C3Light
C3MeshGeometry
C3Camera
C3StreamGeometry
C3Material C3SubdivisionGeometry

13. Objects Talk Together
Value Sphere A
1.7 Radius
Cube B
Transform
Parent Transform
Cube C
Transform
Size

14. Objects Talk Together
Value Sphere A
1.7 Radius
Cube B
Transform
Parent Transform
Cube C
Transform
Size
Style Group 1 Style Group 2

15. Coping with Diversity
• Objective-C is high level
• Sometimes, subclassing is your enemy
• And then, categories are your friend
• Renderer interface & file read/write’s as
categories of existing classes

16. Category Use
Ceed3D.framework C3Sphere C3Mesh
Ceed3DGL.framework +GL +GL
Ceed3DRenderMan.framework +RenderMan +RenderMan
+POV +Obj
+3ds
+Collada
+ ...

17. Focus on OpenGL
• Modern OpenGL only (no legacy calls)
• Support for OpenGL ES
• Sophisticated Shader Definition

18. Focus on OpenGL
• Modern OpenGL only (no legacy calls)
• Support for OpenGL ES
• Sophisticated Shader Definition
Ceed3DGL • Thin Objective-C layer for
OpenGL
CeedGL
Ceed3D • Encapsulates GL objects
(texture, buffer, framebuffer, program,
shader...)
GL CeedMath • Defines Draw Commands

19. Cocoa Interactions
• KVO / KVC: easy access to object inputs/outputs
• Core Image: CIImage used as textures, CIFilter as post
process filters on rendered image
• Quartz: NSBezierPath used as geometry source, incl. glyphs
• Quartz Composer: Ceed3D should be able to render as a
QCPlugin, QC outputs usable as Ceed3D textures
• Grand Central Dispatch: Parallelism for computations
• OpenCL: Geometry filters

20. Examples
! sphere = [C3Sphere sphere];
! sphere.radius = 0.15;
! sphere.translation.z = 0.3;
!
! C3GenericMaterial *material = [C3GenericMaterial genericMaterial];
! material.diffuseColor = [C3Color redColor];
! material.environmentImage = [C3Image imageWithContentsOfFile:
! ! [[NSBundle mainBundle] pathForResource:@"skydome_1024" ofType:@"jpg"]];
! sphere.defaultMaterial = material;
!
! [scene addNode:sphere];
!
! NSBezierPath *path = [NSBezierPath bezierPathWithRoundedRect:rect
! ! xRadius:0.1 yRadius:0.1];
! [path appendBezierPath:[[NSBezierPath bezierPathWithOvalInRect:
! ! NSInsetRect(rect, 0.15, 0.15)] bezierPathByReversingPath]];
!
! id options = [NSDictionary dictionaryWithObjectsAndKeys:C3DOUBLE(0.02),
! ! kC3MeshOptionAdaptiveSubdivisionDistance, nil];
!
! C3MeshGeometry *geom = [C3MeshGeometry meshGeometryWithBezierPath:path
! ! options:options];
! C3Mesh *mesh = [C3Mesh mesh]; [mesh insertObject:geom inGeometriesAtIndex:0];
! [scene addNode:mesh];

21. Examples
! glRenderer = [C3GLRenderer new];
! glRenderer.scene = scene;!
! glView.viewer.camera = camera;
! glRenderer.viewers = [NSArray arrayWithObject:glView.viewer];
! pixarRenderer = [C3PixarRenderer new];
! pixarRenderer.outputDirectoryPath = @"~/Render/Ceed3D-pixar";
! pixarRenderer.scene = scene;
! aqsisRenderer = [C3AqsisRenderer new];
! aqsisRenderer.outputDirectoryPath = @"~/Render/Ceed3D-aqsis";
! aqsisRenderer.scene = scene;
// ....
[glRenderer render];

22. Demo

23. Demo
mesh = [C3Mesh meshWithAttributedString:@"" options:nil];

24. Availability
• Work in progress
• Low-level, stable parts will be released as
open source soon
• We want to release more later...
• Stay tuned!

25. Thank you!
Raphael Sebbe
Twitter: @rsebbe