How to 3D model solid color object

PIX4Dmapper PIX4Dmapper Questions/Troubleshooting
1

So I did an ortho flight and suplimented with manual shots around a water tower and I got some blank spots on the model. I assumed because the sun on one side was washing it out making it find no points to model with. I got this.

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So now I went on cloudy day and hoped I would get better results but I got worse… Its like it found nothing on the sides at all.

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So are their any tricks to trying to get a solid colored object ? I know it needs to find some difference in lighting to know there is a point but with it all same color that is hard. I’m sure super close up it can find them. So just checking if anyone had any tricks. Like can you do manual shots with the iris low to help pick up points or anything I can do to help it find points to render it better. When you put the mesh on it, that doesnt help much. The second one makes it look like you crushed a water bottle (left) and the first attempt is blotchy (right)

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any tips or tricks are appreciated.

2

Hi Kevin,
These homogenous surfaces are very difficult for all the reasons you discovered. The best tip I can give is to keep your overlap very high. Perhaps in the 90% range.

3

ok thanks… on this same topic… two questions on how pix4 works.
If I take a picture of the side in shade and then later that day I take picture of it in the sun in the same pseudo location as far as x,y,z and camera. Then I use both pictures in my project, I assume PIX4d would attempt to use both correct… and try to get info from either right ?

secondly… what causes images to be not georectified ? I went out to this same location and took tons of pictures on the side that was in the shade, now in the sun and most of them had that issue. Was I just too close to the object and it just saw blue… or does it just come down to the fact that it could not find matching points from photo to phone since its all pretty much blue.

4

Photogrammetry requires good image texture to work well. If there are not a lot of features in the image, then they will become uncalibrated. This means that the software cannot spatially place the image. Using good-quality images becomes the most important aspect. Consistent lighting is very important otherwise it cannot match common features.