Using '.png' image for texture

I use ‘png’ image for texture.texture
But when i move the camera i can see the object inside the wall.Just like the wall become ransparent.
I dont know why.

Could you include your code and a demo, e.g. using Codepen, Glitch, Neocities, etc.? Doing so makes it much easier for others to help you, otherwise we’re just guessing.

oh! sorry, here is my code

var mtlLoader = new THREE.MTLLoader();
var objLoader = new THREE.OBJLoader()
	mat.side = 2;
			var name =;
		        if (name.indexOf('_') !== -1) {
		                mesh.material.transparent = true;
		                mesh.material.side = 2;
		         } else {
		               var matArray = mesh.material;
		               matArray.forEach(function (mat) {
		                  mat.transparent = true;
		                  mat.side = 2;
		                 mesh.castShadow = true;
		                 mesh.receiveShadow = true;

i can see the object inside the wall.Just like the wall become transparent.
I dont know why.

I’m not sure I understand the issue — your code is setting material.transparent = true . I can’t see your model (this is why a demo is ideal) but it seems like this is exactly what your code should do?

this is my model file.Please take a look at the model.

check this link

Can you share the model, mtl, and all textures?

You could try setting mat.depthTest = false

ofcourse , but how to share my model to you?1
i upload the model but nothing at all.