シリンダー（3Dモデル）を上下に動かすだけのシンプルなiPhoneアプリのサンプルコードを描いてみます。
使ったもの
・cylinder.hシリンダーのモデル情報
動かすとこんな感じです
サンプルコード
#import “ViewController.h”
#import “cylinder.h”
@interface ViewController () {
GLuint v;
GLuint nv;
float angle;
float height;
}
@property (nonatomic, strong) GLKBaseEffect *baseEffect;
@property (nonatomic, strong) GLKView *gv;
@property int direction;
@property float distance;
@end
@implementation ViewController
– (void)loadView
{
self.view = [[GLKView alloc] initWithFrame:CGRectMake(0, 0, 320, 568) context:[[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES3]];
}
– (void)viewDidLoad
{
[super viewDidLoad];
self.gv = (GLKView *)self.view;
self.gv.drawableColorFormat = GLKViewDrawableDepthFormat16;
[EAGLContext setCurrentContext:self.gv.context];
self.baseEffect = [[GLKBaseEffect alloc] init];
self.baseEffect.light0.enabled = GL_TRUE;
self.baseEffect.light0.diffuseColor = GLKVector4Make(0.5f,0.9f,0.4f,1.0f);
self.baseEffect.light0.position = GLKVector4Make(-0.8f,-0.8f, 6.0f,0.8f);
self.baseEffect.light0.ambientColor = GLKVector4Make(0.2f, 0.8f, 0.7f, 1.0f);
glClearColor(.2f, .6f, .6f, 1.0f);
glGenBuffers(1, &v);
glBindBuffer(GL_ARRAY_BUFFER, v);
glBufferData(GL_ARRAY_BUFFER, sizeof(cylinderVerts), cylinderVerts, GL_STATIC_DRAW);
glGenBuffers(1, &nv);
glBindBuffer(GL_ARRAY_BUFFER, nv);
glBufferData(GL_ARRAY_BUFFER, sizeof(cylinderNormals), cylinderNormals, GL_STATIC_DRAW);
glEnable(GL_DEPTH_TEST);
glEnable(GL_BLEND);
glEnable(GL_CULL_FACE);
}
– (void)glkView:(GLKView *)view drawInRect:(CGRect)rect
{
[self.baseEffect prepareToDraw];
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glBindBuffer(GL_ARRAY_BUFFER, v);
glEnableVertexAttribArray(GLKVertexAttribPosition);
glVertexAttribPointer(GLKVertexAttribPosition, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(GLfloat), NULL + 0);
glBindBuffer(GL_ARRAY_BUFFER, nv);
glEnableVertexAttribArray(GLKVertexAttribNormal);
glVertexAttribPointer(GLKVertexAttribNormal, 3, GL_FLOAT, GL_FALSE, 3*sizeof(GLfloat), NULL + 0);
const GLfloat aspectRatio = (GLfloat)view.drawableWidth / (GLfloat)view.drawableHeight;
self.baseEffect.transform.projectionMatrix = GLKMatrix4MakeScale(0.3, 0.3 * aspectRatio, 0.1);
GLKMatrix4 result = GLKMatrix4MakeRotation(-M_PI/3.0, 1, 0, 0);
if (self.direction == 0) {
// down
result = GLKMatrix4Translate(result, 0, 0, self.distance);
self.distance -= 0.1;
if (self.distance < –5) {
self.direction = 1;
}
} else {
// up
result = GLKMatrix4Translate(result, 0, 0, self.distance);
self.distance += 0.1;
if (self.distance > 5) {
self.direction = 0;
}
}
self.baseEffect.transform.modelviewMatrix = result;
glDrawArrays(GL_TRIANGLES, 0, cylinderNumVerts);
}
@end