World Point projection in a Shader Pass

Questions
4

Thank you for clarifying. I have tried in the vertex shader

      scene0 = vec4(.0, .0, 1.0, 1.0 );
	vec4 viewPos =  inverse(cameraWorldMatrix) * scene0;
            scene0 =  projectionMatrix * viewPos; 
		    test = scene0.xyz ;
gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );

and

 scene0 = vec4(.0, .0, 1.0, 1.0 );
			vec4 viewPos = viewMatrix * scene0;
            scene0 =  modelViewMatrix * viewPos; 
		    test = scene0.xyz - cameraWorldPos;
		 	gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );
	```


 scene0 = vec4(.0, .0, 1.0, 1.0 );
			vec4 viewPos = inverse(cameraWorldMatrix) * scene0;
            scene0 =  projectionMatrix * viewPos; 
		    test = scene0.xyz ;
		 	gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );

the problem remains, the point displays slightly off depending on the camera orientation. maybe it would be from thecalculated distance in the fragment shader?

The fragment shader is (that i have got from a previous question here: WorldPosition in shader - #2 by HEOJUNFO
):

    float depth = getLinearDepth( vUv );
    float fragDepth = texture2D(tDepth, vUv).r;
    float viewZ = perspectiveDepthToViewZ(fragDepth, cameraNear, cameraFar);
vec4 viewPos = getViewPosition(vUv, fragDepth);
    vec4 worldPos = cameraWorldMatrix * viewPos;

//HEATMAP
float intensity = distance(test.xyz, worldPos.xyz );