ARKit + SceneKit. Scaled triangles appear after applying depth video with alpha channel on SCNPlane

I think distortions appear (meaning scaled triangles) like in the image below

Seems like this code might be the solution.

Can anyone explain what this code does?

sampler linearSampler = sampler(     filter::linear,     mip_filter::linear,     max_anisotropy(8) );

float center = u_displacementTexture.sample(linearSampler, _surface.diffuseTexcoord).r; float x_up = u_displacementTexture.sample(linearSampler, _surface.diffuseTexcoord, int2(1, 0)).r; float x_down = u_displacementTexture.sample(linearSampler, _surface.diffuseTexcoord, int2(-1, 0)).r; float y_up = u_displacementTexture.sample(linearSampler, _surface.diffuseTexcoord, int2(0, 1)).r; float y_down = u_displacementTexture.sample(linearSampler, _surface.diffuseTexcoord, int2(0, -1)).r;

float threshold = 0.01 / scn_commonprofile.displacementIntensity; if (abs(x_up - center) > threshold || abs(x_down - center) > threshold || abs(y_up - center) > threshold || abs(y_down - center) > threshold) {     discard_fragment(); }