SceneKit: how to create chessboard pattern for SCNFloor from image? - scenekit

Question

The goal is to create an infinite chessboard pattern.
Using a SCNFloor and the attached image, we produce something close but not quite like a chessboard. Some black squares merge where they shouldn't.
We tried different values for Scale, WrapS, WrapT, Min filter, Map filter, and Mip filter. The screenshot shows the current values.
Is the underlying image not correct, or what setting do we need to change for the SCNFloor?
Repeated image:
Result:

Answer 1

#import "GameViewController.h"
#interface GameViewController ()
#property (nonatomic) CGFloat chessBoardWidth;
#property (nonatomic) CGFloat chessBoardDepth;
#property (nonatomic) CGFloat tileWidth;
#property (nonatomic) CGFloat tileDepth;
#property (nonatomic, getter=isOdd) BOOL odd;
#end
#implementation GameViewController
-(instancetype)init {
self = [super init];
if(self) {
self.chessBoardWidth = 10.0f;
self.chessBoardDepth = 10.0f;
self.tileWidth = 1.0f;
self.tileDepth = 1.0f;
}
return self;
}
-(void)awakeFromNib
{
[super awakeFromNib];
// create a new scene
SCNScene *scene = [SCNScene sceneNamed:#"art.scnassets/chessboard.scn"];
// create and add a camera to the scene
SCNNode *cameraNode = [SCNNode node];
cameraNode.camera = [SCNCamera camera];
[scene.rootNode addChildNode:cameraNode];
// place the camera
cameraNode.position = SCNVector3Make(0, 0, 150);
// create and add a light to the scene
SCNNode *lightNode = [SCNNode node];
lightNode.light = [SCNLight light];
lightNode.light.type = SCNLightTypeOmni;
lightNode.position = SCNVector3Make(0, 10, 10);
[scene.rootNode addChildNode:lightNode];
// create and add an ambient light to the scene
SCNNode *ambientLightNode = [SCNNode node];
ambientLightNode.light = [SCNLight light];
ambientLightNode.light.type = SCNLightTypeAmbient;
ambientLightNode.light.color = [NSColor darkGrayColor];
[scene.rootNode addChildNode:ambientLightNode];
// Material
SCNMaterial *blackMaterial = [SCNMaterial material];
blackMaterial.diffuse.contents = [NSColor blackColor];
SCNMaterial *whiteMaterial = [SCNMaterial material];
whiteMaterial.diffuse.contents = [NSColor whiteColor];
// Geometry
SCNPlane *blackTile = [[SCNPlane alloc] init];
blackTile.firstMaterial = blackMaterial;
SCNPlane *whiteTile = [[SCNPlane alloc] init];
whiteTile.firstMaterial = whiteMaterial;
// Parent node
SCNNode *parentNode = [[SCNNode alloc] init];
[scene.rootNode addChildNode:parentNode];
self.odd = YES;
for (uint x=0; x < self.chessBoardWidth; x++) {
for (uint z=0; z < self.chessBoardDepth; z++) {
// Add tile
SCNNode *tileNode = [[SCNNode alloc] init];
if(self.isOdd) {
tileNode.geometry = blackTile;
} else {
tileNode.geometry = whiteTile;
}
[parentNode addChildNode:tileNode];
// Position tile
tileNode.position = SCNVector3Make(self.tileWidth * x, 0, self.tileDepth * z);
// Alternate
if(self.isOdd) {
self.odd = NO;
} else {
self.odd = YES;
}
}
}
// set the scene to the view
self.gameView.scene = scene;
// allows the user to manipulate the camera
self.gameView.allowsCameraControl = YES;
// show statistics such as fps and timing information
self.gameView.showsStatistics = YES;
// configure the view
self.gameView.backgroundColor = [NSColor grayColor];
}
#end