Vtk-js: Rotate Volume issue

[aneeshikmat]

Hi, I have a volume render, and I would like to rotate it in Desktop/VR, but I have issue in both of them, When I set myVolume.rotateX(interValue) volume is rotate but some of data is missing like this image:

the volume result in image after I rotateX 33 degree, I think this issue related to 858.

Any way, is rotate action a truth way to rotate volume? Since if I use camera view up nested of rotate, its work nice on desktop, but in VR not working truth since VR has left and right projection/view matrix and maybe I need to build a new matrix for that, Im not sure...

Additional Note:
VTKJS Version: 11.1.0
Browser: Google Chrome 77.0
OS: Windows 10 64 bit.

Thanks for help.

[jourdain]

When you manipulate the camera programmatically, you need to reset the clipping planes.

For the VR, I'm pretty sure right now vtk.js does not properly handle volume rendering in VR. Only geometry is supported. @martinken feel free to add any comment.

[aneeshikmat]

Thank you @jourdain , but when I using renderer.resetCameraClippingRange(); Its no effect, in browser return false, and nothing change....

[jourdain]

And when you rotate the volume using the mouse drag, do you see the full volume or are you also running into visual artifacts?

[aneeshikmat]

After programmatically rotate and reset clippingRange, mouse is keep volume work as visual artifacts, not full volume ...like image in my question...

[jourdain]

Oops, I misread the initial message. The rotation happen on the volume, not on the camera... Disregard my camera comment.

I guess the Volume transform is not properly taking into account. But if you want to work on the vtkImageData instead, you can adjust the transform matrix unless you are really looking for having several representations of that same image data with different orientations?

[aneeshikmat]

Thanks Jordain,

mmm, I think I need a several representations since I call a 3D render and crop it, get Dicom slice after cropping also using vtkVolumeController to control density and so on....I think vtkImageData not support it....else if not understand it...LOL.

[jourdain]

My guess is that you don't need to rotate the volume. You just need to point the camera to the volume properly.

[aneeshikmat]

What I need is rotate volume programmatic like mouse behavior when you rotate volume....so that I use rotate volume....

[jourdain]

Why don't you rotate the camera programmatically? Is the visual result the same?

[aneeshikmat]

Since if I rotate camera, its will work in Desktop perfect, but when camera rotate, the VR behavior will work unspected, so that I change the idea to rotate volume nested of camera, but visual artifacts are seen in desktop/vr when use rotate ...

[jourdain]

You can also adjust the VR camera as well. But since you want to rotate the volume at the representation level, that's fine.

BTW, based on what I can understand from your explanations, the vtkImageData does exactly what you are looking for. But it is true, that you should also be able to define transform on Props so I'll stop suggesting workarounds that will let you move forward.

[aneeshikmat]

I will work in your suggestions, Thank you a lot for your time.
And I will try to add/build a rotate representation level for our vtk.

Thanks again.

[aneeshikmat]

Hi @jourdain

After trace rotate code, and take look at direction for input data, we can change the way for rotate data, we can build Orthogonal matrix from Rotation matrix and pass it to setDirection(), this way will make rotate work perfect with direction, I test it and implement it in my code, and all is good....

For example for my work (sample of code):

  publicAPI.customRotate = (degreeValue) => {
    var outPutMatrix = [[0,0,0],[0,0,0],[0,0,0]], outPutMatrixFinal = [[0,0,0],[0,0,0],[0,0,0]];
    var rotateX   = [[1, 0, 0], [0, Math.cos(degreeValue), -Math.sin(degreeValue)], [0, Math.sin(degreeValue), Math.cos(degreeValue)]];
    var rotateY   = [[Math.cos(degreeValue), 0, Math.sin(degreeValue)], [0, 1, 0], [-Math.sin(degreeValue), 0, Math.cos(degreeValue)]];
    var rotateZ   = [[Math.cos(degreeValue), -Math.sin(degreeValue), 0], [Math.sin(degreeValue), Math.cos(degreeValue), 0], [0, 0, 1]];
    vtkMath.multiplyMatrix(rotateX, rotateY, 3, 3, 3, 3, outPutMatrix);
    vtkMath.multiplyMatrix(outPutMatrix, rotateZ, 3, 3, 3, 3, outPutMatrixFinal);

    // return rotateX, or rotateY or rotateZ for single plan or outPutMatrixFinal for all plans;
  }

After I implement this way, Volume is rotate in Desktop/Vr without any issue, so that I share it, and no visual artifacts seen, I wish its be helpful too like your suggestions before.

Reference