Normal Map Help

animatr

Hi there. I'm tryin to get into normal mapping, which i see many people use here, and I'm having a lot of problems. The first one is what do i do? My tools are 3ds max 7 and Zbrush2. I made a very simple wall in max that i wanted to import into zbrush and high poly it to no end...except everytime i import, it seems like all the verts welded in at some point and it looks nogting like a wall at all. I exported my max model as an obj. i left all settings default. I then went into zbrush and imported from the tools pallete and i cant get it to work. It's quite frustrating because i know this technology is becoming a must have skill for a 3D artist and there seems to be no help of any kind via tuts on this subject. I'm looking for tuts or advice on the prob i have mentioned. I have come across many tuts on how to build things in Zbrush, but at this point, I consider myself an environment artist and see no reason to build environments in zbrush. Thank you for any advice

jeremy




EDIT: added the pics so everyone can see what I'm asking

poopinmymouth

Should answer some, if not all your questions

http://www.fileplanet.com/dl.aspx?/planetquake/polycount/tutorials/video/zbrush2_max7.zip

animatr

thanks poop for the video tut. It helped with some max things, but i guess im wondering how to get the model in zbrush from max correctly, and then how to generate a normal map in zbrush to bring back in max. ive also played with the render to texture dialogue a bit with some pauldrons i made, and it renders out my normal map completely red everytime. I know its something Im doing wrong, just dont know what.
thanks for the help with the vid tut tho!

MoP

Here's a little tutorial I wrote for CGChat a while back, maybe it will be of some use to you.

http://www.cgchat.com/forum/showthread.php?s=&threadid=20424&perpage=15&pagenumber=1

Also you say you used the default settings for exporting the .OBJ files from Max to ZBrush, try fiddling around with them (if your model is all quads, tell the exporter to use quads) ... also slap the "Number of Digits" up to 12, just in case.

MoP

animatr

thats too funny, just got done reading your tutorial actually. it was really helpful, yet still didnt work with my thing i was working on. I should probably upload pics so someone could point out exactly what my problem is. I tried doing the high res in max this time, nothin fancy, just added some extrusions here and there, and it just isnt workin. I followed your tut step by step. Im so confused!
Ill get some pics up
thanks

flachdrache

You did saw the tutorial vids in zBrush2 ? - make sure you also road the "Practical Manual.pdf".
In the manual is a article how to handle in/export with different mdlprogramms.

If the import "changes" the form of the model - take a look into the helperfunctions of Zbrush2. There is something like "welding vertexes by import" - maybe your model is too small / the settings are too high (radius).

Josh_Singh

dude, just make sure your model is in editible mesh rather than an editible poly. and export as an obj and you should get it into zbrush fine.

MoP

Well, I always export as Editable Poly, .OBJ set to quad geometry, I've never had a problem with that.

animatr

okay, first of all thanks to everyone who has answered my question! I finally got my model into Zbrush, worked pretty well. Now, hopefully someone knows how to answer this, now, i want to experiment with this idea in max, creating my lo poly, and then my high, and using RTT to project hi onto lo. Ive read Mop's tut on cgchat and perhaps im missing a step or maybe a base concept. The image above, I made the basic pauldron, then cpoied it over, added some minor details, and then I aligned it back to the low poly pauldron so that i could go to RTT. the i adjust the push value on the cage after reseting it and the render looks absolutely terrible. It has weird black streaks in it and looks all jagged...
not sure whats going on. And I'd love to know where everyone else learned normal mapping...jobs? school? the max tutorials are terrible and they use their own models, so of course its setup to work :P

as far as zbrush goes, just have to learn how to sculpt in it now. now that i figured out the right settings to import.
thanks for any tips and all the previous help!
jeremy

Eric Chadwick

Show us the UV layout. Sounds like a UV problem...

MoP

I would recommend using NURMS subdivision on your high poly model, I think if you just add detail to the low poly mesh without subdividing it, you're gonna get poor results when you render to texture.
I usually build the high-poly (high detail) model first, using Editable Poly and subdividing it so it's all smooth (use 2-3 edges very close to each other if you want a hard edge in the subdivided mesh), then once the high-poly mesh is complete, build a low poly object around the shape.

Make sure the UV-maps of the low-poly object are not mirrored, flipped or on top of each other. They need to be laid out so no parts are overlapping, and it probably helps if they're not back to front, too.

The screenshot you give as an example is showing that you're not really using the right methods for normal mapping - your high poly object should really be smoothed, not just a copy of the lowpoly mesh with a bit of extra detail added in - that just doesn't cut it. And kinda defeats the object of normal-mapping too.

MoP

animatr

Thanks MoP! that really helps. Im currently a student about to graduate from Digipen in seattle, and Bay Raitt had come to our school saying that we needed normal mapping in our cirriculum but we still dont have that so i thought id try it out on my own, wsant sure of the concepts entirely, so that really helps. Thanks a bunch. gonna try this out later on!

Eric Chadwick

animatr, here are some images I posted awhile back to help someone else who was new to the modeling process for normal mapping. These models were created by one of the other artists here, James Ku. They aren't as perfect as they could be, but when you're on a schedule you can't always afford perfection. Anyhow, they're working well for what they're made for.

A closeup of the high-res model that's used to create the normal map, with MeshSmooth turned on:


The same model, but without MeshSmooth, so you can see the actual wireframe that's being used to create the subdivision:


And then here's the low-res in-game model that the map will be applied to:


And here it is with the normal map:

Some seams here and there, but some will be fixed by the game engine (UV mirror seams), and others will be hidden by the color map or because the player can never get this close.

Not that this is the best example, but it might give you a flavor for how it can be used.

moose

another thing to watchout for is sever angles when working with raised surfaces. in order for the raised areas to show up on the normal map, they need to have a beveled look (ala photoshop's bevel and emboss). ie, if there is a raised set of faces, you will want the edges to slope down rather than slope inward. (like a hill, not a cliff) it doesnt have to be drastic - it can be slight, 90 degree angles generally will not show up.

putting 4 or 5 spans on the edges of the higpoly to really soften it out will cause a smoother transition on the normal map, and require less channel painting work on it. you can still have a sharp edge, but you will get much better results if the 'sharp' edge is a slightly rounded sharp edge... if that makes sense.

Cubik

Poop, about your Z-Brush video, there's actually a pretty easy way to attach more than three fingers (and make it look correct) to one Z-Sphere:
The problem:
http://206.145.80.239/zbc/showthread.php?t=24163
The solution:
http://206.145.80.239/zbc/showthread.php?t=23136
The script:
http://206.145.80.239/zbc/showthread.php?t=3405

animatr

Thanks everyone for all your help. Hopefully I'll have time this week to dive back into this and explore it some more. I appreciate all the help!
thanks
jeremy