Rendering issues when importing custom models

[Robert]

I'm new to 3D modeling, and relatively new to TTS, so I'm probably doing something wrong. When I import models, some (but not all) have weird, bulging, lumpy geometry where my Tinkercad model had smooth, simple curves or even flat surfaces and right angles. The weird thing is that I can't seem to figure out why it happens to some details on some models, but not others.

For example, here are two big ships with lots of tiny detail and two smaller ships with much less details. The big ships rendered beautifully, down to the 0.5mm flagpoles, but the smaller ships, with simpler geometry and little detail, came out lumpy and bulbous.


To make it weirder, the smaller ships were built out of copies of the big ships' Tinkercad models. That is, I just duplicated the big ship model, made some modifications, and exported it as the small ship. But it both cases, the big ship looks great, and the small ship, not so much.


I even took one of the small ships and added a whole bunch of extra detail to it, to see if that would counter-intuitively improve the render. What I found was that some tiny details (like the 0.5 mm rows of pipes) rendered very nicely, while simple things like the side of the hull got deformed. And holes that I added to one surface rendered perfectly, while holes I added to another surface turned into strange indented X's.


Has anyone else had problems like this? At first, I just thought I'd hit the rendering limits of TTS, but then I tried those two big, highly-detailed ships just to see, and they turned out great. So, I'm assuming either I'm doing something wrong, or there are specific things that TTS can render well and certain things it can't, but I can't figure out what they are.

Thanks

[Knil]

Your smoothing groups aren't setup correctly in your 3d modeling program for those models.

[Robert]

Your smoothing groups aren't setup correctly in your 3d modeling program for those models.

A friend of mine thought that might be the problem, so she looked at the models in 3DS Max, and told me that there weren't any smoothing groups. In fact, I'm pretty sure Tinkercad (the modeling program I'm using) doesn't even support smoothing groups. Maybe TTS is set up to automatically assign smoothing groups? That would explain why things are getting smoothed that don't need to be. Maybe?

[Robert]

Your smoothing groups aren't setup correctly in your 3d modeling program for those models.

I've had the models checked for smoothing groups, and there aren't any. Plus, I don't think Tinkercad (the modeling program I'm using) supports smoothing groups. Any ideas on what could be causing this? Here's a link to the [URL="https://drive.google.com/open?id=1UYdvWyJwTY2ruglpITKFus0yhfhJJWcC"]highly-detailed model[/URL] that renders almost perfectly

and one to the [URL="https://drive.google.com/open?id=1yDOTy9H6DxMIb2DJSEBDiua8CVkdMwuD"]much simpler model[/URL] that renders not nearly as well.

Any help would be much appreciated--I love TTS, but my unfamiliarity with 3D modeling is really holding me back.

Thanks!

[LordAshes]

I've had the models checked for smoothing groups, and there aren't any. Plus, I don't think Tinkercad (the modeling program I'm using) supports smoothing groups. Any ideas on what could be causing this? Here's a link to the [URL="https://drive.google.com/open?id=1UYdvWyJwTY2ruglpITKFus0yhfhJJWcC"]highly-detailed model[/URL] that renders almost perfectly

and one to the [URL="https://drive.google.com/open?id=1yDOTy9H6DxMIb2DJSEBDiua8CVkdMwuD"]much simpler model[/URL] that renders not nearly as well.

Any help would be much appreciated--I love TTS, but my unfamiliarity with 3D modeling is really holding me back.

Thanks!

I'm not sure if this is related or a separate issue but I also have issues importing OBJ files into TTS. However, I don't get deformation as much as I get missing faces. For example, I grab a Mixamo (great source for RPG characters) and then I add a cylindrical base to the bottom of the character. When I look at the results in 3 different 3D modeling software that I have (Anim8or, Blender and 3DXChange) it look correct. However, when I bring it into TTS, the top part of the cylinder and the back part are not rendered. I found similar problems with other content that I try to import.

If I had to guess, I would think that it might be a problem with the face normals which indicate which way a face is facing. I am guessing TTS only renders one side of the faces and thus any faces whose normals are pointing away are not rendered. However, since the content seems to render correctly in other software, it may be a bug in TTS which is not rendering normals information correctly.