Photogrammetry Texture Seams

 When joining two halves of the same fossil it sometimes leaves a noticeable seam. Due to the way each half is created using 3DF Zephyr each part is exposed to different lighting. 

Some, like the ammonite, could be fixed quite easily by adjusting the tint of the texture in UE4 by multiplying the base colour texture. However, others, like the mosasaur tooth, may be more difficult.

There were a few methods I was going to try when attempting to fix the seam. The first being the method that I used for the ammonite. Adjusting the tint of the base colour in UE4's material editor was enough to balance the colours on the ammonite and remove the seam almost perfectly. I did a lot of trial and error with the ammonite since it was my first photogrammetry attempt and in the process, I was able to keep the lighting mostly consistent throughout but the creation of the mosasaur tooth was more difficult. However, after trying this with the mosasaur tooth, I now know that I was just very lucky that the ammonite's seam was that simple to fix.

Because I had to orient the tooth differently for it to be properly recreated by 3DF Zephyr, the light was hitting the object from two different sides on each half. This meant that matching the colour on one side would make the other side either too dark or too light, depending on the side that was matched.

My second option was using photoshop to manually alter the colour of the relevant UVs. Unfortunately, because of the messy automatic UVs of 3DF Zephyr, this made it almost impossible to tell which faces were where. It would have been far to complicated to even attempt so I moved onto something else without trying this one.

The next option, I had was using Substance Painter to manually match up the colours by painting directly onto the object. This would avoid the need for finding specific faces and would mean I could be very detailed with the colours. This worked better than I thought it would and allowed me to perfectly remove the seam, keep the imperfections in the colour of the stone using the eyedropper and was very quick and painless.

The whole process took only about an hour and the changes in colour I was able to capture made this method by far the best was of removing the seam. Because each material is isolated in Substance Painter, I could paint on the bottom texture without affecting the colours of the top, making matching the colours very easy. The only downside to this method is that I was painting over the graininess of the stone and replacing it with solid colour.

To counteract this, I used the same normals generation website that I used for the starfish fossil. This added the grain back to the object despite it being missing from the texture around the object's seam. I am very pleased with the result and think this is a fantastic way to cover up the seams. The fact these seams can be easily covered up only makes my work and my workflow, of creating an object in two halves, more viable.