I am following the tutorial (https://www.youtube.com/watch?v=ntUy_3AMsTs&t=1647s) to make my picture to be a character on CTA3. I save my dissected body part pictures into PNG file on Adobe Photoshops as it suggested. Then I import the body parts into CAT3 composer's mode to make a new character based on G2's skeleton with my body part pictures. 

Could you provide your image to me, I will try to help you check your issue.

I found out the problem. When I use Adobe Photoshop to save the png file, it was saved in 16-bit in the "Image--> Mode" part. I changed it into 8-bit image, there is no problem to upload the PNG file anymore. 

I found that it is very difficult to reconstruct a G2 character that has no glitches when the character is in motion. I imported the body parts into a character, but the Head-neck-Body connection and  the Hip-Body connection is very complex. There are several pivot points that have to be coordinated. I really has a hard time to move them (even following a well-down video like this, https://www.youtube.com/watch?v=ntUy_3AMsTs&t=1647s) . In that video, the character has no neck, but its movement has no problem at all. I have an hard time to move those points along the spine. If the dot moves, then the pictures don't stack well. So I guess the trick of alignment must be in the position of point when I position the picture. 

Any tip that helps me to understand the trick will be very appreciated. 

 

I think you'll find your answer in the online manual.

Setting Connection Points

Dell XPS 8900, Intel(R) Core(TM) i7-6700 CPU @ 3.40GHz, 3408 Mhz, 4 Core(s), 8 Logical Processor(s), 16 GB RAM, - 4 GB GeForce GTX 745, NVIDIA compatible.
Acer Aspire V Nitro Laptop,  2.5GHz Intel Core i5-7300HQ processor with 6MB cache,  256GB solid state drive, 16GB Ram,  4 GB NVIDIA GeForce GTX 1050 Ti graphics.

Thank you, Kyle, for your kindness. I have solved the PNG issue.  

Thank you very much, Snarp. You nailed it. I follow the manual and fixed two joint problems. But I still have a problem when my head is doing forward bending in 'Head Rotate' calibration. My body part eventually stands up while my head is bending forward. 

More tricks to learn

Alex