Hi there! Recently I’ve been practicing modeling stuff in 3DS Max 2012 and now I think it’s time for me to go to the next step which involves “baking” a high poly version of your model to the lower poly version. I’ve been trying to understand the whole concept and so far this is what I know:
(Please correct me if I’m wrong)
The low and high poly models should have a similar frame, so basically they’re the same and the only thing the higher poly version has are tiny details such as bumps/lumps or other little details on its body.
One of them should “cage” the other. This is where I’m confused, should the higher poly be the cage and have the lower poly fit inside it, or is it the other way around?
From what I’ve read, there are numerous ways to achieve a great looking low poly model. Some people start modeling a high poly version first before making low poly ones, while others start with their modeling program to build a basic model first before making a high poly version. Some time ago I asked somebody for advice about where to start especially if I’m using the model in a game (which will be heavily animated of course), and the answer I got was “Start modeling the basic version first so you can make the topology easy to animate, especially with how everything flows.”
I thought that the advice was reasonable, especially on the part about focusing on making the model easy to animate first before making it pretty. I quickly modeled a simple creature for fun to study how to bake high poly models to low poly ones and ended up with something I call “Battle Worm”, a giant worm that sucks energy from the planet and shoots out energy blasts from his mechanical cannon arms lol!
Anyway I exported Battle Worm into an OBJ file and imported it using Zbrush. Just to be sure, I saved different versions of Battle Worm as Ztools, beginning from his basic form and up to when I detailed him a little (I can only divide it up to 5).
Well, I’m not so sure as what to do next, or maybe I made the mistake of texturing him already. I think just now I remember reading from somewhere that from 3DS Max, you get the model into Zbrush, then you divide to whatever your machine can handle. The result of the division would be the model that you’ll sculpt since it is the high poly version. Well, it gets fuzzy here since I’ve been trying to gather information from multiple sources and they all use different tools and methods lol!
I’d really appreciate it if someone can tell me how the whole process is done when the only programs you have are 3DS Max 2012, Zbrush 4, and Photoshop, thanks:smile:
Those are the only 3 tools you would need. Try googling “Render to Texture” “Projection Map”, if you absolutely cant find out how , maybe gimme a PM , its an easy process, but you have to flip through about 5 or 6 windows… lol.
Hey thanks! Those were the exact phrases I needed to search for, not simply “bake high poly to low poly” lol! I quickly found relevant information. The only problem I’m currently having is when I’m trying to bake, my pc can’t handle it and runs out of memory! I think the high poly is TOO high poly for Max, so I’m gonna go use Decimation Master in Zbrush to bring down the count of the High Poly… hope it works
Wow, I finally got it to work:) I didn’t know the process was actually easy!
I was able to get most of the detail from the high poly version on to the low poly one, but I just rushed it and didn’t bother to adjust the cage since I simply wanted to see how good it can do when rendered using the default cage position. I’m pretty sure that with enough cage adjustments, the lower poly one would really look exactly like the high poly version!
Here’s the tutorial that finally showed how easy the thing is. I just adopted the methods to the 2012 version of Max, good thing they’re still where they’re supposed to be lol!
Create a basic low poly version of my model in 3DS Max 2012 and export it as an OBJ.
Import the OBJ using Zbrush 4.
Divide the model’s geometry up to the max my pc could handle (which is 4 or 5).
Sculpt the model at the highest division without going too wild, just little wrinkles and bumps here and there for the model.
Use Decimation Master in Zbrush to reduce the polygons/vertices of the high poly model, which reduces the possibility of 3DS Max 2012 crashing or not working when you want to finally “bake” the high poly model to the low poly one.
Export the high poly detailed model as an OBJ.
The Actual “Baking” Part:
Import the high poly model into 3DS Max 2012.
Name it “HighPoly” just for reference.
Assign it an empty material (just because the tutorial said so).
Import the low poly OBJ file you sent Zbrush earlier, you’ll notice that this low poly model is placed exactly where the high poly version is, and they look as if they’re one!
Name it “LowPoly” just for reference.
Assign it an empty material (just because the tutorial said so).
Click Render → Render to Texture while LowPoly is still selected.
Projection Mapping → Check Enabled, Check Sub-Object Levels, put mark on Full size. Click Pick → Choose HighPoly then click Add. Click Options → Check Use Cage. Click Setup → Check Enable Global Supersampler, choose Max 2.5 Star from drop down. Close the windows until you’re back to the Render to Texture window.
16.Mapping Coordinates → Put mark on both Object and Sub-Object’s Use Existing Channel options.
Under Output, click Add and choose NormalsMap, click Add Elements.
Under Selected Element Common Settings, Check Enable, Target Map Slot select Bump.
Under Selected Element Unique Settings, Check Ouput Into Normal Bump.
Minimize the Render to Texture window for a while, it’s time to “adjust the cage”.
The Cage Adjustment Part (idea is to make the cage eat the low poly model since the high poly version has a slightly different figure after you sculpt it from Zbrush):
The low poly model should still be selected. Go to the Modifiers panel and you’ll see that it now has a Projection modifier.
Choose Cage in the Projection modifier.
Find the Cage section in the modifier and Check Shaded.
Just below Shaded, click Reset.
You’ll see some lines pop up from the model. That’s the cage. Some of the lines are sinking in the model. What you have to do is to raise those lines so that they’re on top of the model’s body parts.
After you’re done adjusting the cage to eat up the model, go back to the Render to Texture window you minimized earlier and finally click Render.
You’ll notice that a TGA file will be created called LowPolyNormalsMap in the folder you specified files to be saved.
Make sure the low poly model is selected and press M to bring up the Materials Editor.
Find the one you created for the low poly version. According to the tutorial there should be a bump map entry automatically created, but in my case, there wasn’t! What I did was just remove the old entry since it was pretty useless, created a new Standard entry, dragged Bitmap into it, chose the LowPolyNormalsMap.TGA that we recently got, and then connected it to the Bump node.
After setting up the bump node with the TGA file, click Assign to Material and Show in Viewport, just make sure to pick the one that has “Shell” in it to show the changes to the low poly model.
Please correct me if I got something wrong (because what I did seemed right). It might look like there’s a lot of steps but in practice, it’s actually very quick:shock: I guess the cage adjustment part is the only thing that’s really time consuming if you want things to be perfect.
I’m just glad there’s Decimation Master in Zbrush, otherwise, my machine would just cry and fail every time lol:smile:
Easiest workflow is to build your low poly mesh in Max, then create your high-poly mesh by subdividing your low-poly INSIDE Zbrush, and then export the Normal map using Zbrush without touching 3DS Max.
Keep in mind you should set up your UV space before subdividng or you will have to auto-UV within Zbrush or use methods outside of Zbrush (like you just did) in order to project onto a different UV space.
One of the key things is, you can push your poly count up very high in zbrush, and with z4, you can set it up to bake/connect all the maps using the goz plugin. Instead of exporting your highest subdivision, try going down to 1 or 2 lower ones, and delete the lowest below that, so goz will export from there (or you can manually export that) - use that medium detail mesh to actually bake, taking your high resolution textures from the highest level mesh.
As Mab says, build your low poly in max. You can actually do this after you create your high res mesh too, either by re-topologizing, or taking the medium mesh, exporting that, and freezing it in max to use as a base to build a new one around. With some of the topology tools in max, this is a very fast process, and will likely get you the best low poly result.
Take advantage of that map exporting process tho, likely you wont have to bake anything, but there are a lot of ways to go about the whole process so whatever ultimately works for you, go with it.
Your lopoly should always cage the highpoly meaning if you have a flat surface with a dent on it, the lowpoly should cage everything but not have a dent.
Simply said your lowpoly will cage the highpoly because your rendering the details on the lowpoly.
Therefore if a surface with a dent already on it tries to do a futile operation of simulating that dent trough the map leads nowhere.
Use X normal- Its free and it renders multiple maps and it has a documentation thats is fairly small if you wanna grasp different concepts and what the maps do and how to set up an optimized version.
^
my best pick ( maya renders the best normal maps but for sake of speed use xnormal and you can render some things like cavity map and occlusion map
eyther use one of the two on the texture map to add shadows baked onto ur map.
Or use it on the normal map to add more depth.
your choice on wich you use. i find the occlusion is the bigger picture while cavity adds smaller details
Extra info on xnormal : the best part abbout xnormal is that if you save an obj file from say zbrush / mudbox that is say 10 milion pollys. Xnormal will render out a beautifull map.
to this day you cant realy do that in maya/max.
Allas u never actualy need 10 mil pollys but just an example of how far advanced your maps can be.
frequent forums like polycount, they have good wikis. and you will learn basic terminology and techniques , tips and tricks.
A build lowpoly version of what you intend to sculpt.
B Map the uv layout that i will be using.
(B2) Alternatively using Zbrush´s Zspheres / Dinamesh i sculpt a base mesh then using decimationmaster i import it to max/maya and build a lowpoly resembling it, then i uv map it.
C Import to zbrush
D sculpt @ 1 mil polly lvl - part
E Export high sculpt - import it to xnormal / Bake maps
F Use maps on lowpoly.
G Cleanup map in photoshop / add detail using cavity map and add more detail on texture map using occlusion map.
i find it quite fast. usualy takes only a half hour to do it all.
