Is there a way to view the raw voxels?

[evanmjensen]

Hello,

I'll elaborate slightly... I've built a coil in code. I'm interested in seeing exactly how many voxels are in the cross-section of the coil. I know the diameter of course, and I can estimate it by my dimensions in my call to PickGK.Library.Go(0.3f, OurClass.Helix);, however I'd love to see a mode where there is no tessellated interpolation and I can view the output more like "minecraft" where I can see the exact data in voxelized form.

I've been successful in exporting the voxelized form to a vdb file by using: voxLat.SaveToVdbFile(), however I have trouble viewing it effectively in blender. Is there a way to view the part in voxel-space natively at "design time" while writing code?

I'm trying to hit critical machine dimensions for laser powder bed fusion so the voxel-by-voxel interaction is critical in my application.

Thanks!

[soigniert]

Unfortunately I can't answer your question and would like to hear if there is a solution for your matter - but assume there is none. As written in this discussion the voxels object is not just discrete. I assume you have to create a scalar field from it and then probe it/count the voxels in a certain region as described in that discussion by Lin.

Let me also elaborate:
Why would you not want the smoothed display for manufacturing? If you create a .stl for manufacturing it will get smoothed as displayed. If you use slice data like .cli files, the manufacturing also profits from smoothed curves (at least up to a certain degree of manufacturable resolution). The laser in laser powder bed fusion is fastes and well positioned for lines that do not change direction a lot. 90° angles as of voxel data is worst for the scanner and often compensated by the hardware. Even for pixel based additive technologies, such as binder jetting or stereo lithography with masks (MSLA, DLP, LCD) it is state of the art to use antialiasing, in order to smooth the surface.

If you really need the cubical mesh or to change the type of smoothing, changes at the backbone of PicoGK's runtime would be necessary.

Best
Alex

[evanmjensen]

Alex,

Thank you for the response.

I appreciate the insight into anti-aliasing for "pixel based" tech, however I'm dipping my toes into the world of multi-material laser powder bed fusion (MM-LPBF), where the powder itself is deposited in pixel (voxel) form in each layer. What I'm trying to visualize is essentially this problem:

If I'm attempting to "clad" a material (grey) with for instance a high refractory material (pink), I'm more likely to dimension my geometry to get the resulting voxel layout on the right side of the image rather than the left side where I might not have enough material deposited.

I'm trying to work in the "critical size" that my equipment supports, so I can get the most performance out of it, for instance, the thinnest viable cladding layer possible with a MM-LPBF system.

Its possible I'm thinking of this incorrectly, but I'd hate to find "holes" in my cladding when I'm over in the post-processing / CAM software when I could evaluate it at design time instead.

The discussion link was helpful, so I'll see what I can do there, potentially building some analysis tools.

[cariboo22]

Hello @evanmjensen,

This might be a bit late, but I have found a way to get what you want.
First, export your Voxels in vdb file format :

OpenVdbFile oFile = new();
oFile.nAdd(yourVoxel);
oFile.SaveToFile("outputfile.vdb");

When it is exported, you can now open the output vdb file in Paraview (it is an open-source post-processing visualization engine). Use Paraview version 5.10 or above (versions 6.0 and above do not support VDB files).
When the file is opened, click on Apply (red square on the capture), you should now see a white box. You can change the display representation by selecting something different than Outlines (green square), for example you can select Surface With Edges.

Now you should have a box full of voxels. The useful geometry is hidden inside. To filter the output, click on the button to apply a threshold to the voxels (red box). Then change the Upper Threshold to 0 (green box), click Apply. Finally, change the representation to Surface With Edges and voilà!

Best,
Eliott

[evanmj]

Thank you Eliott! I'll give it a shot. The visualization you have looks like exactly what I wanted. I'd love to do this "in viewer" but these steps should be reasonable for when it matters. I tried essentially this in Blender, but I was unable to apply visual effects to shade the cells appropriately.

[evanmj]

Eliott,

Thank you for this! I was able to get this working on Paraview 5.13.3, but not on 5.10.1 (for anyone else trying). This is also a much richer visualization than default PicoGK which is great for early prototyping. Thank you for taking the time to write out the answer. I'll mark it when i get into my other account.