我尝试在同一几何体上应用两种不同的材料。一种用于平铺的材料,另一种用于环境遮挡和其他效果。
我以DAE格式导出一个带有2个UVSet的模型(没关系)。当我尝试应用第二种材料时,它永远不会出现。在第二个材料上,我尝试应用blendMode,transparencyMode,png文件等。没有任何作用:((如果我在第一个材质上更改mappingChannel,映射就可以了!
let mat1 = SCNMaterial()
mat1.name = "Mat1"
mat1.diffuse.mappingChannel = 0
mat1.diffuse.contents = UIImage(named: "somePNGFile.png")
let mat2 = SCNMaterial()
mat2.name = "Mat2"
mat2.diffuse.mappingChannel = 1
mat2.diffuse.contents = UIImage(named: "otherPNGFile.png")
cube.geometry!.materials = [mat1, mat2]
这是我的SCN文件:https://drive.google.com/open?id=1ddbE815hlS0VbKPsbwcJoS9cL8hOf6Mt
我的代码有什么问题?也许3D文件...如果你有一个想法,一个建议,一个解决方案,那就太好了。
谢谢
最后,我找到了一个shaderModifiers的解决方案。
可以在不同的插槽(环境,漫反射,镜面反射等)上分配不同的mappingChannel。来自Apple的参考文档:https://developer.apple.com/documentation/scenekit/scnshadermodifierentrypointsurface?language=objc
这是我的代码:
var mat:SCNMaterial!
var model:SCNReferenceNode!
override init() {
super.init()
// INIT
initModel()
initShader()
assignTextures()
}
func initModel() {
let url = Bundle.main.url(forResource: "Test_MixMaterials", withExtension: "scn", subdirectory: "Test.scnassets")!
model = SCNReferenceNode(url: url)!
model.load()
self.addChildNode(model)
if let cube = model.childNode(withName: "pCube1", recursively: true) {
mat = SCNMaterial()
// Define mapping Channel 0 on diffuse slot
mat.diffuse.mappingChannel = 0
// Define mapping Channel 1 on ambient slot
mat.ambient.mappingChannel = 1
// Assign material
cube.geometry!.firstMaterial = mat
}
}
func initShader() {
let shader = """
// Samplers 2D.
uniform sampler2D texture_UV1;
uniform sampler2D texture_UV2;
// Directives
#pragma transparent
#pragma body
// Source Diffuse ------------------------------------------------------------------------------------------------------------
vec4 source = texture2D(texture_UV1, _surface.diffuseTexcoord);
// Destination Diffuse --------------------------------------------------------------------------------------------------------
vec4 dest = texture2D(texture_UV2, _surface.ambientTexcoord);
// MULTIPLY Diffuses ---------------------------------------------------------------------------------------------------------------
_surface.diffuse = source * dest;
"""
mat.shaderModifiers = [
.surface:shader
]
}
func assignTextures() {
let setTexture_1 = SCNMaterialProperty(contents: UIImage(named: "someImage.png")!)
let setTexture_2 = SCNMaterialProperty(contents: UIImage(named: "otherImage.png")!)
mat.setValue(setTexture_1, forKey: "texture_UV1")
mat.setValue(setTexture_2, forKey: "texture_UV2")
}
这是工作......
如果你想测试,这是我使用的模型:https://drive.google.com/open?id=1ddbE815hlS0VbKPsbwcJoS9cL8hOf6Mt