How would you bake this octopus tentacle?

Fabazo · Feb 2020

Hi there!

I'm trying to bake my high to low and i'm having some issues around the suction cup thingys. The first image shows the tentacle at the tapered end of the mesh (which lacks detail, cause of less geometry.. but that's a problem for another time). The second shows the same bake but at the middle of the tentacle arm. The third image shows the same part of the middle but without the baked normal map. The fourth image is the current UV map and lastly the 5th image is the high poly and low poly next to each other.

Making a cage for this is pretty hard as you'd might expect so I did the bake inside of substance painter without a cage. What is shown here is a 4k bake with 8x antialiasing and the rest of the settings are at default. I have tried changing all variables but have not had any sucess. I have tons of padding on the uv-shells between the suckers so theres no spilling from the other shells. The majority of the bake looks great, but as you can see in the first image I am getting some weird artifact on the side. And on the second image (in the middle of the arm where there is more geometry in general) there are small kind of cuts on the sides. I'm no expert in baking and I have very little time until this has to be finished and put into Unreal Engine so I'd appreaciate any help I can get. Let me know if you need any more information!

Thanks!

Image: https://us.v-cdn.net/5021068/uploads/editor/vs/kzc51hgp890t.jpg

Image: https://us.v-cdn.net/5021068/uploads/editor/pq/a10cdek61kms.jpg

Image: https://us.v-cdn.net/5021068/uploads/editor/cc/rkaclse82ndp.jpg

Image: https://us.v-cdn.net/5021068/uploads/editor/34/a0ve5bxjam4r.jpg

Image: https://us.v-cdn.net/5021068/uploads/editor/zh/ctkc9s1svb19.jpg

oglu · Feb 2020

Just make a cage. Invest 60min and you have a great one.

thomasp · Feb 2020

For an asset of that size I'd approach the model differently: as a tentacle assembled from neatly unwrapped modular assets with seamless textures. Then add some variation to the material via vertex color masks or as decals and add irregularity to the mesh (e.g. via vertex noise/random offsets).

Blaizer · Feb 2020

What i firstly see is that your UVs are not well optimized. In the second udim, you could "rectify" almost all uv chunks, and do a better use of the uv space, with the needed padding. It will translate to better tiling/seams and texel density.

But if you are in a hurry, forget that. But bear in mind the UVs are not very well, and you could easily save 1 texture sheet.

You always can create a cage mesh. Make a copy of the mesh, push the faces, and manually fix the zones with overlaps. Like oglu said, it could be around 60 min.

Fabazo · Feb 2020

oglu said:

Just make a cage. Invest 60min and you have a great one.

Yeah I probably should make a cage! And previously I thought that the cage mesh had to be pretty much identical to the Lowpoly, but after Blaizer said that I could push and move the faces around manually I can see how I could actually manage to create a custom cage!

thomasp That does actually sound alot more convenient! My mindset is kind of stuck with creating asset for VFX and such, so I haven't really wrapped my head around the whole modularity + optimization stages that games require. We actually talked a bit about decals this week at UNI so i might try to incorporate that into the arm aswell. Perhaps make some vines or seaweed hanging from the tentacle with the use of decals.

We had weekly feedback and my teacher told me that I had to rethink my entire process. So my new approach taht I will try out is to retopo half of the mesh (even though its not completely symetrical) and then mirror the mesh. Then I will try to bake the normals with stacked UVs to save on some texture space since I wasn't allowed to have UDIMS for my asset.

I can't really find any examples of when UDIMS has been used in videogames.. have you guys heard any game that utilized it?

Thanks for the responses!

Obscura · Feb 2020

Unreal Engine now natively support udims. I'd imagine it will start spreading more in games in the upcoming years. Unreal does excellent job compressing them. Virtual textures tends to compress much better than simple dxt from what I can see. It kinda acts like tiff so identical pixels reduces the size by a lot. A 4k virtual texture with few useful pixels will compress to a few kb. Its very promising so far.

Fabazo · Feb 2020

Obscura said:

Unreal Engine now natively support udims. I'd imagine it will start spreading more in games in the upcoming years. Unreal does excellent job compressing them. Virtual textures tends to compress much better than simple dxt from what I can see. It kinda acts like tiff so identical pixels reduces the size by a lot. A 4k virtual texture with few useful pixels will compress to a few kb. Its very promising so far.

Cool! I am much more interested in working with visualization and more high quality film like productions in Unreal so It would be nice if UDIMs became more widely adopted and optimized for unreal.

Fabazo · Feb 2020

Im still having troubles with this mesh.. So I made a cage very simply by scaling the normals outwards and then adjusting the ones that got messed up. I am only baking half of the mesh since I later on am going to mirror one of the sides over. When I bake without I cage i get pretty decent results except for on the suckers. The UV is not final, but I just made a simple and quick one to test out if this will work or not. I have tried every possbile solution I can think of to get to work, but I just can't manage.

Image: https://us.v-cdn.net/5021068/uploads/editor/rd/13hhnpu8ef0f.jpg

Obscura · Feb 2020

Play with the ray distance settings.

Ghogiel · Feb 2020

Is the scale of the model reasonable (ie not really tiny)? are pivots and transforms reset the same? You shouldn't get those artifacts with a cage unless the HP is truely intersecting with it, which you can't see it from those images.

How would you bake this octopus tentacle?

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