Alpha blending in three.js - three.js

Question

I am trying to volume render the raw data using three.js. The raw data can be of any type. For rendering the data I have written code:
dims is an array of size of data in three axes:
One of the data dims is [256, 256 128] and data is uint8Array(8388608).
var texture = new THREE.DataTexture3D(data, dims[0], dims[1], dims[2]);
var texture = new THREE.DataTexture3D(data, dims[0], dims[1], dims[2]);
texture.format = eval(format[1]);
texture.type = eval(format[0]);
texture.minFilter = texture.magFilter = THREE.LinearFilter;
texture.unpackAlignment = 1;
material = new THREE.ShaderMaterial({
uniforms: uniforms,
vertexShader: shader.vertexShader,
fragmentShader: shader.fragmentShader,
side: THREE.BackSide,
transparent: true,
blending: THREE.CustomBlending,
blendEquation: THREE.AddEquation,
blendSrc: THREE.SrcAlphaFactor,
blendDst: THREE.OneMinusSrcAlphaFactor
});
This format array is from a function that checks the format of the data.
function findFormat(dtype) {
console.log(dtype);
let regex = /(u*)(int|float)(\d+)/ig;
let format = regex.exec(dtype);
if (format[3] == 8) {
dtype = ["THREE.UnsignedByteType", "THREE.RedFormat"];
}
if (format[3] == 16) {
dtype = ["THREE.UnsignedShort4444Type", "THREE.RGBAFormat"];
}
if (format[3] == 32) {
dtype = ["THREE.UnsignedByteType", "THREE.RGBAFormat"];
}
return (dtype);
}
I am just checking the data type if it is 8/16/32 bits.
This is the output I am getting :
This is iso type:
This is mip type output :
What I believe is that opacity is not active in these so all of the rendered layer or object is looking as an opaque object. This is a required output or looks like these :
I don't understand how to perform alpha blending in this.