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3D graph to plot surface data

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Hello LV community,

I'm working on a program that is supposed to acquire data from several pressure transducers and to display the pressure distribution on the surface of a vehicle in a wind tunnel. I've attached an imaged that shows how it is supposed to look like. This image was created in Tecplot, but this program is not suited to acquire data.

 

I've also included a vi with some code. by now the code perorms the following steps:

1. display the vehicle outer shape in a 3D graph

2. add contour plots of the measuring data

 

now, I got stuck with some issues and I hope you can give me a hint:

1. the scene is not isometric which leads to distorted body dimensions. is it possible to set the ratios of the x : y : z axis to 1.

2. I don't get the measuring data to be displayed as a surface contour. The boxes (item 3 of the graph) are all in place so the data seems to be ok. is that an issue of triangulation??

3. the vehicle doesn't look very three-dimensional. I played around with some lights, but that was not satisfactory

 

I appreciate your comments.

Best regards,

David

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Hi David,

 

I did a little experiment with the new 3D picture control with you model and data. It might be an alternative approach to you problem.

 

The aspect ratio of the actual 3D graph control alters the appearance greatly. Also manually adjusting the axis min and max value can help. I added this in the green section in your VI.

 

The order of the points that make up the surface is important when interpreted as triangles. If you use the 3D mesh (see the other attached VI) you can specify the index (order) of the vertices.

 

There are more flexible lighting options using the new 3D picture control.

 

Hope that helps.

Ruben 

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David! wrote:

...

 

now, I got stuck with some issues and I hope you can give me a hint:

1. the scene is not isometric which leads to distorted body dimensions. is it possible to set the ratios of the x : y : z axis to 1.

2. I don't get the measuring data to be displayed as a surface contour. The boxes (item 3 of the graph) are all in place so the data seems to be ok. is that an issue of triangulation??

3. the vehicle doesn't look very three-dimensional. I played around with some lights, but that was not satisfactory

 

I appreciate your comments.

Best regards,

David


 

I'd love to look at THAT data in the 3d graph but i am stuck at LV 8.5 on my home machine. Smiley Sad

 

1)

 

The scale ranges can be specified. In the following image from this thread I turn-off autosclaing for the Z-axis (index number 3) and set the range explicitly.

 

 

 

2)

Not sure if I follow the "surface contour" request unless you are talking about a color mapping (W-axis) of the pressures onto the surface as I did in this image.

 

 

 

3)

The order of your data is important because it implies which points on the surface are are adjacent to each other.

 

If you get an 8.5 up this week-end I'll try to take a look. If after that then LV 8.2.

 

Ben 

 

Retired Senior Automation Systems Architect with Data Science Automation LabVIEW Champion Knight of NI and Prepper LinkedIn Profile YouTube Channel
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I cobbled together my own data.

 

Play with the value to get a an idea of how they affect the simple image. Then adapt to your real data.

 

 

The lighting comes into play wehn you view from underneath.

 

 

 

Have fun,

 

Ben

Message Edited by Ben on 03-29-2009 06:10 PM
Retired Senior Automation Systems Architect with Data Science Automation LabVIEW Champion Knight of NI and Prepper LinkedIn Profile YouTube Channel
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This one better illsutrates the lighting.

 

 

 

Ben

Message Edited by Ben on 03-29-2009 06:34 PM
Retired Senior Automation Systems Architect with Data Science Automation LabVIEW Champion Knight of NI and Prepper LinkedIn Profile YouTube Channel
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Hello Ruben and Ben,

thanks for your responses.

setting the axis limits manually fixes the apect ratio issue. But still, if I understand the functionality of the control correctly, I think it's a drawback that the axis ratio depends on the width to height ratio of the control.

 

I've also tried working with meshes, but wasn't aware, that the appearence depends so much on the order of the data. Proper sorting of the data will probably fix the issue.

 

@ Ben,

I like your colorful car! When looking at it, I got the idea to use just one dataset for the vehicle and the data and work with w-values for the car body that are outside the range of the measuring data. Then, by using a "smart" custom colormap I should be able to differentiate. I think that is easier than having multiple datasets for the body and the different measuring areas. Your color map and transparency vi can be a great help for me.

 

Thank you  again for your input, I'll let know of my progress.

 

I've also included the vi with the changes Rubens did as a LV 8.5 version.

 

Regards,

David

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HI David,

 

I am glad that ispired a solution.

 

Please post an image of your final results if possible. I really like 3d images of real world pehnomenon.

 

Ben

Retired Senior Automation Systems Architect with Data Science Automation LabVIEW Champion Knight of NI and Prepper LinkedIn Profile YouTube Channel
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