Tuesday 28 October 2014

Baking... yet another eternal quest

Baking my Rocket Raccoon Railgun down has been annoying to say the least but I may have got to good point and definitely have learnt a lot about baking in the process.

To start with I was talking to Rich about baking and he imparted some of the wisdom from his own quest for the perfect bake. As I this was a hard surface project I took Rich's advice by setting the smoothing groups up so that anything with a harsh angle was set to be a hard edge on the low poly and then separated the UVs so that the different smoothing groups weren't welded together on the UV. It seems that most things talking about baking explain this as the way to do things including Scott Homer's presentation that was everywhere last week if you're interested in this stuff this presentation is awesome to study! Go study!

This technique however didn't lead to the desired result, I can't say why... computers are evil masterminds of rationality so I must have done something not quite right. You can see that the edges are unrealistically sharp and in comparison to the high poly the baked version just doesn't look right. So I continued to play around, got fed up and set everything to one smoothing group as I had done before and that ended with a blobby mess.



Then I realised that the normals were being forced to, in effect, work too hard. The shape of the mesh was such that having everything on one smoothing group was forcing the normal map to counter the effect of the smoothing groups and straighten out the surface again. As most of the pieces in the asset have inards and are kind of like 3D "C" shapes I realised that having the same smoothing group going round the outside and inside was just a bit too much so I applied a different smoothing group the inside of the "C" and baked it down, here is what the edges look like in comparison to the high poly.

Ignore that smoothing error on the right side of the low poly I'm working on that.
During these series of experimentations I modified the shape of the low poly to fit better with the sculpted high poly, I took off corners that were too harsh before etc. I'm now in the process of going through everything and re-baking and adjusting the low poly I have a feeling that this should be worth the time I've spent on it. Unfortunately the normal maps themselves look like they've got worse but their effect has got better...

Blogger's compression has got worse :(

Put simply I'm confused :) This is not a tutorial on what to do but more my experience so far trying what should technically have worked and didn't...

3 comments:

  1. YOU MUST DO WHAT RICH SAYS, Can't stress that enough, seperate smoothing groups and seperate islands in your UV's it may be that your high poly isn't soft enough to pick up that detail. Try making the chamfers softer and they will give you a much nicer result. Remember they have to translate to pixels in the texture sheet, so 1 pixel thin chamfer will look crappy baked. Which is why you exagerate stuff.

    Any questions you can PM me on Facebook. I probably have some examples of some bakes, or you can send me that file and I get you a perfect bake

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    Replies
    1. I know! :( but it doesn't work properly for this for some reason. going to do some more experiments and try and work out why it doesn't work.

      There's a chance that for this project I may just make it look right instead of be technically perfect. I've already sculpted and worked on it a lot by this point. I want it to be as good as possible but I also want to finish a project! I'm just confused as to why it would work with 2 smoothing groups and not with separated UVs. I would have thought they would both have the same amount of pixels for the edges.

      As I said, this is not a tutorial but what I've found with this one project. Cheers dude, more playing needed. If I get too annoyed I may have to take you up on that offer ;)

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  2. Don't do things for the sake of making it good for your folio its much better to make mistakes and learn from them. If someone in an interview asks you how you made something and you give them the incorrect answer it will look really bad. Your much better off taking a bit longer and making it look good the correct way.

    Its not a technical thing, this knowledge on baking is essential I use what I have learnt baking everyday, its invaluable to know how to do things right as when you are expected to bake a model it should be done quickly and to the best quality possible, if you fuck about trying it on one smoothing group or split UV's yada yada, your lead won't be happy.

    You should take me up on that offer, don't be afraid to ask for advice and send models it will take me like 2 mins to bake that.

    Also you can find out more in Mike's tutorial

    https://www.youtube.com/watch?v=frPuPNA0daY&list=UUl-_vaauUDOpvL1HiEKi0AQ


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