Simplified model looks bad (weird lines,...)

Hello everyone,

I created a high detail model, which then had more than 9mio vertices and 19mio faces and also was more than 3gb when exported as .obj file, so I used the “Simply” tool to reduce it to 200k vertices.

The problem is: The resulting mesh looked horrible! Not only did the triangles look off and kind of all over the place but there also were a couple of lines through the model, like it had been cut into cube-shaped pieces, then sloppily put together again (sorry, didn’t take any screenshots). The preview and high detail mesh both didn’t show any of these lines and even the former looked like it had cleaner triangles.

What could have happened here? Are there specific settings you have to use when simplifying a high detail mesh, steps you have to do to get a proper result? Would it be better to reconstruct the model into a mesh that already has the desired number of vertices, instead of creating the high detail mesh (which takes multiple hours), then simplifying it (and how do I do that)?

Hi Simutech21,

what were your Simplify settings? Did you simplified in one step or in more steps (it is recommended to simplify not more than 50%). 

Thanks for your reply! It was set to 600k triangles/300k vertices (so 3%) and I didn’t change any of the other settings (“Absolute” type, reprojections disabled, part merging enabled). Afterwards I didn’t even bother unwrapping/re-texturing, so I don’t know if that would have made a difference. I just noticed that the high quality model is split into 11 parts (must have happened automatically during reconstruction) and where these meet is exactly where I noticed a couple of the weird lines.

I also generated the “Normal Detail” model but that still has 4.2mio triangles (2 parts). If I simplify that to e.g. 200k triangles (around 4%), the resulting model looks fine, no line or anything like that where the “parent’s” two parts meet.

What is the recommended way of simplifying to less than 50%?

I wrote it in wrong way. You should do incremental steps during simplification by 50%.

For example: 9M -> 4.5M -> 2.25M until you get the model with wanted number of triangles.

 

 

Oh, I see. What’s the reason behind this? Will it not give you an exact model (as exact as you can be with the lower triangles count) if you simplify by too much in a single step? Do you have to unwrap/texture every simplified model along the way too? Is there a way to automate this?

Sorry for all the questions!

There can be some model corruptions caused by too high simplification, the model parts won’t be preserved well. It is also because, that a lot of triangles are replaced by one and the detail is lost.

You can texture just last model, also you can use texture reprojection.

You can automate the process using CLI commands.