/3/ - 3DCG

[Anonymous No.364679]

T/3/apots, I looked up a ton of info on the net, but after an entire day of trial and error I thought someone here might have a shorter answer.

The top is my original topology and bot is the car's body with normals baked (disregard paintjob) in Unity. There are a few edges like the ones indicated by the arrow that keep bugging me. The UVs do not have a seam there and I made sure to contain the edges in a cage all over the model.

Could you help me pinpoint the issue here? Is the topology horrible? I'm going for tablet/smartphone game models with this so I've been quite a miser with polys after the shape was finished, cutting off every single extra one (seeing how the model won't be animated).

It is still WIP, so any pointers are welcome.

[Anonymous No.364681]

What is bugging you about that edge? If you want to smoothen it you can do that with normals

[Anonymous No.364682]

I can look at this picture for 10 minutes but all I see is "KILL ME" written on it.

[Anonymous No.364683]

>>364681
That's exactly what I tried, and without any seams right there I still get the hard edge after projecting.

>>364682
Allright, can you give some pointers?

Are the dimensions bad, the topology, the look?

I want to fix this so any criticism is good, but please be specific.

[Anonymous No.364684]

I'm also rather afraid to put in too many polys. As the plan is to have about 12 cars in a race + background for a tablet game, how high could I go with the tricount approximately?

[Anonymous No.364685]

>>364683
Welld do you get the same problem in the original 3D program? If no, then it's a Unity specific problem

[VC No.364686]

Hi OP,

what software are you using, and how are you exporting your model?

If you let Unity calculate the smoothing angle of the mesh, you can get ugly results.

In the Project view select the mesh and use Assets->Import Settings...this allows you to give your meshes a smoothing angle or disable automatic normal generation, in which case Unity will read it from the FBX file directly.

Then it will depend on how you exported the FBX file on the result.

For example, Blender does not properly export smoothing in FBX.

[Anonymous No.364689]

>>364685
Yes, I just checked. In both viewport and render screen I can see the hard edges.

It's odd since the normal render preview does show some errors, but none where they can be seen on the model.

[VC No.364688]

addendum

Actually, looking at your model, it looks like the angle of that area is very sharp. You might have to remodel it.

[Anonymous No.364690]

>>364686
>>364688
Hey, thanks for the feedback.

I made the low poly in max, used zbrush to generate a quick smooth (same results as turbosmooth, but I like touching it up there and unwanted angles are much more visible). It didn't smooth really well, so I edited the base model, defining the shapes better and getting rid of ugly folds that appeared when raising subdiv level.

I exported the high poly to max, and projected it multiple times until I got a decent result. Unfortunately, even that one had the issues I'm asking advice on.

Also, as I said here >>364689 the problems are visible while still in max.

I will refine that edge and post results.

[VC No.364692]

>>364690

To be honest, that seems to be a very bad method to do it.

This car is so low poly, you would get much better result by modelling it directly. The mesh looks rather bad and inefficient.

[Anonymous No.364693]

>>364690
Projecting what? Vertex position, vertex normals, or to normal maps?

[Anonymous No.364694]

>>364692
Allright, I figured this method would suck, since I did just piece it together from what I gathered from multiple tutorials. It's what I got at the end of the day and that's why I posted here.

What exactly do you mean by modelling it directly?

Is there any other way to get a smooth look to it?

I'm sorry I ask so many questions right back, but I haven't posted here yet (although I have lurked) and really none of the people I know have 3d experience.

Are there any forums that can help out on such questions?

[Anonymous No.364695]

>>364693
Projected to normals map.

[Anonymous No.364697]

Could you draw a quick guide on the picture as how the mesh should look like? It would help greatly, thanks.

[Anonymous No.364703]

>>364695
As far as I understand there is a significant difference between normal maps and vertex normals, even though of course normals operate on the tangent which is in turn defined by the vertex normals so there is a relationship, but they're not interchangeable. Correct me on this, but I don't think normal mapping results in any mesh smoothing at edges and vertices. Have you tried baking the high res model into the vertex normals of the low res model? You can try manual adjustments to see what you actually need, since baking to vertices on a low poly mesh may be sketchy (I don't use Max and I don't know)

[Anonymous No.364707]

>>364703
Yeah, if you have actual hard edges in your vertex normals, a normal map will not be able to hide that entirely. There will be a wonky visible edge of messed up shading along that area.

Average your normals on the low poly, then bake it from the high to the low, you'll get semi-hard edges from the normal map that looks good, instead of the unrealistically sharp edges vertex normals produce. Such edges don't shade good either and make a model look like shit as the camera moves around it.

[VC No.364726]

>>364697

Sorry, but do not feel like do one more. It's 23:18 here and had a long day.

But the gist is

Only add polygons where they are needed, i.e. very curved surfaces.

Avoid too small detail/polygons. Pointless.

Avoid oddly shaped quads. They won't be triangulated well.

In general, pick one angle for smoothing and use it as a guide while modelling.

[Anonymous No.364743]

>>364726
Thanks a lot. After I posted I started searching for models other people made and I figured out things that I got wrong.

I see what I could have done better from your sketch. Part of my problem was that I was trying to get as few polys as possible instead of thinking the design further along the line.

Thanks again, I didn't expect /3/ to be so helpful.

[Anonymous No.364915]

So, i fixed up the mesh according to your suggestions, then I unwrapped it.

I managed to get the desired smoothing effect with Smoothing Groups.

Top: Max with checker pattern and UV borders.
Mid: Max regular view
Bot: The car viewed in Unity.

Wheels and lights are untouched.

Is it in a better state than it was yesterday?
What could I do to further improve this model and future ones?