SceneKit:如何转换SCNMaterial的内容？

Question

我用SCNBox创建了SCNNode，

SCNBox *wallBox = [SCNBox boxWithWidth:width height:100 length:4 chamferRadius:0];

SCNMaterial *allMaterial = [SCNMaterial new];
allMaterial.diffuse.contents = @"allwall.png";

SCNMaterial *smallMaterial1 = [SCNMaterial new];
smallMaterial1.diffuse.contents =@"bottomwall.png";
        
SCNNode *rightwall = [SCNNode nodeWithGeometry:wallBox];
        
rightwall.geometry.materials = @[smallMaterial1,allMaterial,smallMaterial1,allMaterial,allMaterial,allMaterial];

但是纹理方向的背面是错误的。

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我想要两个方向是一样的，怎么转换SCNMaterial的内容？如何使用"contentsTransform"？

Answer 1

我已经用这个答案解决了这个问题：SceneKit, flip direction of SCNMaterial

rightwall.geometry.materials = @[smallMaterial1,allMaterial,[smallMaterial1 copy],allMaterial,allMaterial,allMaterial];
    NSArray *allMaterial = rightwall.geometry.materials;
    SCNMaterial *smallMaterial2= allMaterial[2];
    smallMaterial2.diffuse.contentsTransform = SCNMatrix4MakeScale(-1,1,1);
    smallMaterial2.diffuse.wrapT = SCNWrapModeRepeat;
    smallMaterial2.diffuse.wrapS = SCNWrapModeRepeat;