volume rendering up to a certain slice

I was playing around with another cool feature, so I have the following slice view with the volume loader It would be very cool to be able to combine this with the volumerendering, so that the volumerender only shows up to the the slice indicated by the volume loader slice index (presumably the Yaxis, but any could be fine). Since the volumerendering is quite heavy on the pc, this would reduce the load and also increase the usefulness, since it can be used to look “inside” certain parts of the scan.

Unfortunately, I’m not very exprienced with threejs/3D in general. But I have tried and look at the AMI code to see what might make this possible; inside helpers.volumerendering.js the following code

this._uniforms.uDataDimensions.value = [this._stack.dimensionsIJK.x,
                                                this._stack.dimensionsIJK.y,
                                                this._stack.dimensionsIJK.z];

If instead of the true stack dimensions, this was passed the dimensions of the stack up to the slice, and was updated using the lut gui (or whatever other gui) whenever the slice index changed, would that show only the volumerender up to the slice index and not further?

[NicolasRannou]

Yes window width/level are available - https://github.com/FNNDSC/ami/blob/dev/src/shaders/shaders.vr.uniform.js#L29-L34

It could also be related to the LUT that you are passing to the VR.helper. See [opacity] in the VR example: https://fnndsc.github.io/ami/#vr_singlepass

Finally the VR shader will need extra work to support to nicely mix slices/meshes inside the visualization.

[NicolasRannou]

@l0uch3 try updating “vrHelper. uniforms.uWorldBBox.value = value;”

var dimensionSlice = stackFolder.add(vrHelper.stack.dimensionsIJK, 'x', 0, stack.dimensionsIJK.x).step(1);
    dimensionSlice.onChange(function (value) {
        if (vrHelper.stack.dimensionsIJK) {
           vrHelper.stack.dimensionsIJK.x = value;
           vrHelper. uniforms.uWorldBBox.value = vrHelper.stack.worldBoundingBox();
        }
    });

There may be a couple more things to be figured out but could already kind of work 😃