It's a spark plug

avenali312

I wanted some practice on the high to low baking process for a hard surface asset, so I went with a spark plug. It gave me the chance to model quickly and get to the baking step quicker. It also had a few different surfaces that gave me some more practice on material definition.

I started by creating a clean version of the surfaces and then moved on to a dirty, used version. The two sets of maps were then set up in Unreal using a scalar to allow transitioning from one version to the other.

Mesh : 6,184 tris

Maps : 2048 x 2048 A / M / R / O / N

Tools : 3ds Max / xNormal / Photoshop / Unreal

As always, feedback is appreciated.

Clean:


Dirty:


Dirty Maps:


High vs Low Poly:

skyline5gtr

It looks pretty spot on to me, but its not really low poly. There are a lot of areas you could try to optimize that mesh

avenali312

Thanks for the feedback! I was considering trying another LOD lower than what it is currently. You've convinced me. I'll admit I was a bit concerned about changing the roundness of the cylinder too much because I knew it would introduce some waviness in the normal, but I guess that's what experimenting is for.

skyline5gtr

Yea you obviously have  the modeling skill down, so try and push it as low as you can and see what happens. Example would be in the twist areas try to bake down to a flat area. Will help you learn as well

igi

Your low-poly isn't that 'low' unless you'll have that spark plug right into the camera angle all the time. Try something like this and gradually reduce the number of cylinder sides as radius getting smaller.

 

avenali312

Thanks, IGI! I will take a look at it later this evening for sure.

JoshWilkinson

"Low poly" is a subjective term. Especially with LODs. This would make a fine cinematic asset but yes, the poly count for something this simple is completely relative to camera distance.

Joopson

At any rate, it looks great. I love seeing really detailed models are things most people don't think to model.

avenali312

Did a really quick pass with a lower level of detail. I will have to pull it into Unreal tomorrow to see how it looks with the rest of the maps. I think it would be totally viable as another version a bit further away from the camera.

Original low poly = 6,184 tris
New lower poly = 1,000 tris

igi

 Looking great but there's still room for optimization. You can reduce the edge counts on the smaller radius sides by collapsing them. You got higher polygon density on the thinner areas then the larger ones right now. And you still have some edges that doesn't really contribute the silhouette. There's an extra champer on the green areas and the red edges can be terminated as they break the roundness of the cylinder as well as giving higher polygon density than the overall mesh. And that edgeloop I tried to mark as blue, doesn't look necessary though.

 

 

Jack M.

There's a few things you'll probably want to do to prevent the warping in the bake I'm seeing here. 

1) You'll want to make hard edges/smoothing groups for each uv island. I use 3ds max and have a script that does that automatically.

2) You'll want to make a cage for your mesh that encapsulates the entirety of the high poly. This tells the baker how far the rays should be cast on the low poly to capture the high poly's data (Key thing here is it gets rid of normal map seams along the breaks in smoothing groups).

3) The final thing you should do is make sure whatever baker you're using has "average normals" unchecked. This will allow the baker to use the exported normals from your mesh.

This is a pretty surface level explanation of what you should probably do.

You should really just read the majestic post by the normal master EQ: http://polycount.com/discussion/107196/youre-making-me-hard-making-sense-of-hard-edges-uvs-normal-maps-and-vertex-counts 

CarlK3D

High poly looks great. If your intention is just for a beauty render then you can keep it a bit higher to reduce any blockiness in the silhouette. Though its good practice to try to keep your meshes low but still looking good. Depending on the size of the object and what distance it will be seen you can estimate your polycount Chances are if this was to go in a game it would be small on screen unless it was held in your hands up close. I went through this a while ago when I made one for our game. I kept it a little higher because it looked good but realized it would only be seen from the ground in a pile so I lowered it a fair bit. Another thing with LOD's is you need to consider the render distance of your asset which will be based on its size so if its small it will render in before an LOD is needed, any less then 500tris and I wouldn't bother adding one 

in-game was 1400 tris but was lowered to 600 because of how the asset was viewed with minimal quality loss, I kept the higher one for renders though  

avenali312

Thanks everyone for the great advice! I'll take it all into account with the next pass.

avenali312

I just wanted to say thanks again to everyone so far. I had a plan of doing something simple like this to get back into the complete workflow (sadly my current job doesn't allow for normal maps or any baking). I figured the simple object would afford great critique with a good focus on technical inaccuracies and you guys have been knocking it out of the park.

avenali312

So, I have a quick question... Is it typical to have to use multiple baking methods on the same object? The reason I ask is, I'm getting much a much cleaner bake of the threaded portion when not using a cage. The cage is introducing more waviness than before. But, I am getting much cleaner bakes between my hard edges and UV islands with the cage. I read through EQ's posts about normals and waviness and am unsure what I'm doing incorrectly with the cage causing more waviness.

avenali312

I took another stab at this and took the lower LOD into Unreal to see what it looked like with all the maps. I'm pretty happy with the results. Here is an image showing a comparison of my initial low (the hero version that has enough triangles to be an FPS weapon haha) and the greatly reduced new low. Triangle count dropped about 90% overall.

CarlK3D

Baking with a cage can cause waviness as you've mentioned on cylindrical objects when baked with a cage. I get this issue a lot. so doing multiple bakes, 1 with the cage and 1 without (for the cylindrical objects) is a good idea if your getting this issue. 
Without a cage you could try Setting Max frontal ray distance to 45 & Max rear ray distance to 5 I've found this normally fixes the cylindrical curving that happens when you bake out 

Tzur_H

You can also try the 'skewmesh' baking way.
https://www.youtube.com/watch?v=u8nvDgvKbSs