如何在Android ArCore Sceneform API中的对象上设置重复纹理？
作者：互联网
我已成功在AR场景中的两个矢量之间建立了一条线.
我的代码：
private void addLineBetweenPoints(Scene scene, Vector3 from, Vector3 to) {
// prepare an anchor position
Quaternion camQ = scene.getCamera().getWorldRotation();
float[] f1 = new float[]{to.x, to.y, to.z};
float[] f2 = new float[]{camQ.x, camQ.y, camQ.z, camQ.w};
Pose anchorPose = new Pose(f1, f2);
// make an ARCore Anchor
Anchor anchor = mCallback.getSession().createAnchor(anchorPose);
// Node that is automatically positioned in world space based on the ARCore Anchor.
AnchorNode anchorNode = new AnchorNode(anchor);
anchorNode.setParent(scene);
// Compute a line's length
float lineLength = Vector3.subtract(from, to).length();
// Prepare a sampler
Texture.Sampler sampler = Texture.Sampler.builder()
.setMinFilter(Texture.Sampler.MinFilter.LINEAR_MIPMAP_LINEAR)
.setMagFilter(Texture.Sampler.MagFilter.LINEAR)
.setWrapModeR(Texture.Sampler.WrapMode.REPEAT)
.setWrapModeS(Texture.Sampler.WrapMode.REPEAT)
.setWrapModeT(Texture.Sampler.WrapMode.REPEAT)
.build();
// 1. Make a texture
Texture.builder()
.setSource(() -> getContext().getAssets().open("textures/aim_line.png"))
.setSampler(sampler)
.build().thenAccept(texture -> {
// 2. make a material by the texture
MaterialFactory.makeTransparentWithTexture(getContext(), texture)
.thenAccept(material -> {
// 3. make a model by the material
ModelRenderable model = ShapeFactory.makeCylinder(0.0025f, lineLength,
new Vector3(0f, lineLength / 2, 0f), material);
model.setShadowReceiver(false);
model.setShadowCaster(false);
// make node
Node node = new Node();
node.setRenderable(model);
node.setParent(anchorNode);
// set rotation
final Vector3 difference = Vector3.subtract(to, from);
final Vector3 directionFromTopToBottom = difference.normalized();
final Quaternion rotationFromAToB =
Quaternion.lookRotation(directionFromTopToBottom, Vector3.up());
node.setWorldRotation(Quaternion.multiply(rotationFromAToB,
Quaternion.axisAngle(new Vector3(1.0f, 0.0f, 0.0f), 90)));
});
});
}
它工作得很好,但我有一个错误的纹理.
在文件“textures / aim_line.png”中包含PNG：
(线的一半是透明的,另一半是橙色的.)
我目前的结果：
但我期待下一个结果：
所以,我使用了Sampler,其中写了“WrapMode.REPEAT”,但纹理不重复,只是拉伸.
如何在Android ArCore Sceneform API中的对象上设置重复纹理？
解决方法:
查看圆柱体模型,它具有0到1的UV贴图.这用于将纹理映射到网格上. 0,0是纹理的左下角,1,1是右上角.仅当模型上的UV坐标> 1时,才使用采样器上的包裹配置. 1.0.在这种情况下,它会根据设置进行钳制或重复.由于圆柱已经被约束为0,1,纹理总是被拉伸.
解决这个问题的替代方法是模拟自己的圆柱体并根据需要设置UV坐标,或者在采样之前使用自定义材质来操纵UV坐标.
您可以使用Blender或Maya或其他3D建模工具制作模型.
自定义材质特定于Sceneform,因此以下是步骤：
>创建加载自定义材质时要使用的虚拟模型
>编写重复纹理的自定义材质
>在运行时加载虚拟模型并获取材料
>在自定义材质上设置参数.
创建一个虚拟模型
我使用了我周围的飞机OBJ模型.模型是什么并不重要,我们只需要它来加载材料.在app / sampledata /材料中创建一个名为dummy.obj的文件
o Plane
v 0.500000 0.500000 0.000000
v -0.500000 0.500000 0.000000
v 0.500000 -0.500000 0.000000
v -0.500000 -0.500000 0.000000
vt 0.000000 1.000000
vt 0.000000 0.000000
vt 1.000000 0.000000
vt 1.000000 1.000000
vn 0.0000 0.0000 1.0000
usemtl None
s off
f 1/1/1 2/2/1 4/3/1 3/4/1
编写自定义材料
custom material reference描述了repeating_texture.mat中的每个元素：
// Sample material for repeating a texture.
//
// the repeating factor is given as repeat_x,
// repeat_y as a factor multipled by the UV
// coordinate.
material {
"name" : "RepeatingTexture",
parameters : [
{
type : sampler2d,
name : texture
},
{
type: float,
name:"repeat_x"
},
{
type: float,
name: "repeat_y"
}
],
requires : [
"position",
"uv0"
],
}
fragment {
void material(inout MaterialInputs material) {
prepareMaterial(material);
vec2 uv = getUV0();
uv.x = uv.x * materialParams.repeat_x;
uv.y = uv.y * materialParams.repeat_y;
material.baseColor = texture(materialParams_texture, uv).rgba;
}
}
将模型和材质添加到构建中
这增加了将模型和材质编译为.sfb文件的步骤.
在app / build.gradle中添加：
apply plugin: 'com.google.ar.sceneform.plugin'
sceneform.asset('sampledata/materials/dummy.obj',
"sampledata/materials/repeating_texture.mat",
'sampledata/materials/dummy.sfa',
'src/main/res/raw/material_holder')
您还需要将Sceneform添加到顶级build.gradle中的buildscript类路径：
dependencies {
classpath 'com.android.tools.build:gradle:3.2.1'
classpath 'com.google.ar.sceneform:plugin:1.5.1'
// NOTE: Do not place your application dependencies here; they belong
// in the individual module build.gradle files
}
}
在运行时加载材料
在onCreate()调用中：
ModelRenderable.builder().setSource(this,R.raw.material_holder)
.build().thenAccept(
modelRenderable – > repeatingMaterial = modelRenderable.getMaterial());
这将材料存储在成员字段repeatingMaterial中.
在材质上设置参数
将原始代码修改为：
private void addLineBetweenPoints(AnchorNode from, Vector3 to) {
// Compute a line's length
float lineLength = Vector3.subtract(from.getWorldPosition(), to).length();
// repeat the pattern every 10cm
float lengthCM = lineLength * 100;
repeatingMaterial.setFloat("repeat_x", lengthCM/10);
repeatingMaterial.setFloat("repeat_y", lengthCM/10);
// 3. make a model by the material
ModelRenderable model = ShapeFactory.makeCylinder(0.0025f, lineLength,
new Vector3(0f, lineLength / 2, 0f), repeatingMaterial);
model.setShadowReceiver(false);
model.setShadowCaster(false);
// make node
Node node = new Node();
node.setRenderable(model);
node.setParent(from);
// set rotation
final Vector3 difference = Vector3.subtract(from.getWorldPosition(), to);
final Vector3 directionFromTopToBottom = difference.normalized();
final Quaternion rotationFromAToB =
Quaternion.lookRotation(directionFromTopToBottom, Vector3.up());
node.setWorldRotation(Quaternion.multiply(rotationFromAToB,
Quaternion.axisAngle(new Vector3(1.0f, 0.0f, 0.0f), 90)));
}
标签：android,arcore,sceneform 来源： https://codeday.me/bug/20191008/1872797.html