Combine two .vti and output a new .vti

[Hanyu_Xu]

Hello everyone:

I have two .vti, as the figure shown (.vti1 and .vti2):

I want to extract material 1 (red particles) in the first .vti, use it as a new material type and add it to the second .vti (vti2 has material 0 to 64). Finally I want to export the output .vti(material 0 to 65). I cannot export output.vti successfully. Could anyone tell me if ParaView is able to do this?

Best Regards,
Hanyu

[Kenneth_Moreland]

Two things would be helpful in answering this question:

1. Please share your data.
2. What do you mean by extracting a material from one image and adding it to another. Do you mean that any point in the first .vti with a material value of 1 should have the corresponding point in the output set to 65, and all other points in the output set to the material value of .vti 2?

[Hanyu_Xu]

Al.vti (26.5 KB)
particles.vti (6.9 KB)

1. Here’s the two .vti, first figure shows particles.vti(containing 2 kinds of materials), second figure shows Al.vti (containing 65 kinds of materials).
2. Sorry for my unclear description. I want to extract all the red points in the first image, treat them as a new material, record their positions, and use these points to replace the points in the corresponding positions in the second image. In the end, I wanna get a .vti as shown as the third image, with 66 materials (the original 65 plus the newly added one). BTW, I image 1 and image 2 have the same size and grid size.

Thank you so much for your reply!!!

Best Regards,
Hanyu

[Kenneth_Moreland]

There are a few steps to do this, but you can get this working by combining the attributes together and using a calculator to conditionally select one value or the other. The steps are as follows:

1. Open particles.vti and Apply.
2. Add the Rename Arrays filter to particles.vti and rename the material array to material_particles.
3. Open Al.vti and Apply.
4. Add the Rename Arrays filter to Al.vti and rename the material array to material_Al.
5. Select both the Rename Arrays filters in the pipeline browser (using alt-click) and add the Append Attributes filter. Apply. This will combine the material arrays from both inputs into a single dataset so that they can be operated on together.
6. Add the Calculator filter.
   • Set the Attribute Type to Cell Data.
   • Set the Result Array Name to material (or whatever other name you want).
   • Set the expression (right below the result array name) to if(material_particles=1, 65, material_Al) This will set the material to 65 if the material from particles.vti is 1, otherwise it will use the material from Al.vti.
   • Apply.
7. (optional) Add the Pass Arrays filter to remove the material_Al and material_particles fields as they are no longer needed.

At this point you can write out the data as a .vti file if you wish.

Here is a state file and screenshot.

combine-materials.pvsm (866.8 KB)

[Hanyu_Xu]

The problem is solved now, thank you sooooo much!!! So kind of you
Wish you all the best!

Best Regards,
Hanyu