SC2 Hydralisk
Hi,
I'm trying to learn game techniques by doing a game model of one of my creature.
I choose an hydralisk and made a low poly model and layed ou its uv.
I'm having some issues while trying to extract a normal map from this model using Xnormal.
You can see the normal map and some of the issue I am encountering.
It seems to occur at thin areas. And sometimes it seems to project the wrong part of the model onto an
other area.
Like if the arm are projected onto the torso.
Here are the models and the uvs.
Do you know what I should do to prevent this?
Thank you.
I'm trying to learn game techniques by doing a game model of one of my creature.
I choose an hydralisk and made a low poly model and layed ou its uv.
I'm having some issues while trying to extract a normal map from this model using Xnormal.
You can see the normal map and some of the issue I am encountering.
It seems to occur at thin areas. And sometimes it seems to project the wrong part of the model onto an
other area.
Like if the arm are projected onto the torso.
Here are the models and the uvs.
Do you know what I should do to prevent this?
Thank you.
Replies
I finally managed to deal with these artifacts, and played with custom cage.
But there is an other artifact I can't get rid of, the ones on the tips.
This creature has many spikes and at everytip it seems to have some difficulty to bake the normal map correctly.
I tweaked the map manually in photoshop using the healing tool, but I'd like to know what is the best method for dealing with these issues.
Here is the screenshot from marmoset
As you can see at every spike tip there is a black spot because of the uncorrect normal map.
Other than that, awesome sculpt!
Thanks
Yenkee: Thanks for the advice, I made new uv for this model but it is not as neat as those incredible layout I can see here.
That's a point where I am clueless, do you move your uv by hand trying to fullfill every space, or is there a magic button? It seems so hard to do that by hand, do you have any workflow example? What should I take into account, for example the islands orientation does it have rules to know and follow?
Here is the current uv layout, I'm using headus uvlayout 2.06.
And what about this one.
It seems quite hard to work with in photoshop, is it an usable approach?
It seems great, but it looks like a big mess too.
Especially for the small parts, like my teeth and spikes.
I will reduces them, I don't know the game constrain you can encounter but I want to learn.
Even if it is for my portfolio it has to be correct.
I first did a version with all the part mirrored but I'm having issue with marmoset along the seem with the normal map.
It doesn't seems to support overlapping uvs or I did something wrong.
Thanks for the feedbacks
I agree with Chrisradsby, try and start with poly painting or a painting app, at least to get started.
I would also bake out an Ambient Occlusion map from XNormal. You can use the AO map as a guide for painting in Photoshop as well. That way you have a better idea of where the form actually is, etc. just from the texture.
Just try different things and see what works best for you. Good luck!
Chrisradsby,I'll use 3D apps but there are a lot of little UVs even with that it is still a big mess. I'm cleaning this right now
Tobbo, I did an half version too. But in marmoset I had issue at seams with the normal map.
To solve this you have to offset the mirrored part to an other UV tile apparently, but I didn't find a way to offset your uv in a corresponding tile in 3DSMax.
Still experimenting.
Regarding the lowpoly and UVs: i think you should optimize more...as someone said you can mirror some UVs, but i wouldn't do just a simple mirror for certain parts cause this is usually quite visible in the center, especially if you have details and tone variation in the texture. Mirroring is useful but dangerous if you don't know how to manage it.
A good solution usually is to mirror in the UVs only the outer areas of an object, leaving the center unique, and the only thing you will have to care about in future is the seam on the other side.
I did a quick sketch to make it clear...
Another thing, as someone said, you have too many micro geometries that usually are not needed unless they help to define the silouette of your character...the rest is done by the norlmal maps. So i would erase pretty much all the small spikes on top of the head and those on the lower body until the big ones start (those are good for the silouette). This low down the polycount, and gives you less headache in the UVs.
Cheers
Thanks for making it crystal clear
I already deleted the spikes on the head, and I tried to deal with the little spikes on the body.
I will delete them like you said, it doesn't help that much the silhouette.
About the mirroring, now that I understand this principle how do you do this in 3DSmax?
You do a simple mirror and weld your geometry or there is a workaround?
And do you know how to deal with the black spot at the top of the spikes?
Thanks everybody for your help.
For the black spots, i'm not really sure, cause i don't use Xnormal but 3dsmax itself for baking (a little slower in rendering, but quicker considering you just do everything in 1 application, anyway it's a matter of tastes).
I can guess that the black spot is due to: (A) a problem with your low poly geometry, not following the shape of the highpoly or (B) a problem with your projection cage, maybe distorted in that point. Keep in mind that when i do the cage in max with Projection modifier, i NEVER ever touch any vertex (except is some extreme situations, to correct some weird cage point). The only thing i do is push the cage out until it doesn't intersect any part of the hi-res mesh.
Concerning the UVs, there is a quite easy process.
1) With your full mesh select one UV island you want to make and unwrap it unique (like you did already). This allow you to have it already simmetrical in the UV space, so your central seam should be vertical.
2) Once you have mapped, go back in the geometry select one half and cancel it.
3) Apply a Simmetry again the half you didn't cancel so that you have again your full geometry, but this time with mirrored overllaping UVs.
4) in the UV editor select the portion of central poligons that you want to be unique,detach them from the current chunk they are attached to, mirror them and stitch the 2 vertical seams together.
It's done! Repeat for all the mirrored pieces (except those that don't have a central seam like arms of course
About the blackspot I thought it was because my mesh didn't accuratly follow the highrez because of the low polycount of my spikes, I will try to fix that without increasing my polycount, I want to test with other uv to see if it can solve the problem.
For the moment here is my new uv sheet, with optimisation on the mesh and overlapping uvs where I could use it. Using your symmetrycal trick and overlapping some teeth and spikes. And the render in marmoset.
But now I have an issue with marmoset, the normal map seems correct but the seams are visible.
If I can add an other question, do you always have to use a projection cage for baking your maps?
If you bake in Xnormal i don't know if it's necessary, personally i never used it.
In 3dsmax yes, it's highly suggested to always add a projection modifier with the cage. There is another way to bake normals in max, named offset (in the baking options you can choose if use the cage or the offset) but doesn't really work well except for flat details... For example, if i have a hard surface model, with details like bolts in many areas and near some seams or hard edges, it's quite probable that baking only with cage will distort those bolts, due to the nature of cage projection. What i usually do i bake first with cage, and them with offset, and then mix the 2 normal maps in photoshop for the best result.
About the seam you have it could be due to the fact that now you have overlapping UV's in certain points. What you should do all the times before baking, is to check if there are overlapping UVs, and if yes, move them of 1 unit in the UV space (meaning that they will be in the same coordinates, but one square next to your texture. they won't be in the main uv area but in the tiled one).
check your vertex , its perhaps a double vertex not welded
generally only for the the hard surface stuff ,but it could help for corrext some issue on organic models
Great sculpt work. If you just starting out, you'll have no problem catching on! I'd just hate to see this awesome creature get anything but excellence! (I'm a huge Zerg fan -- Player)
I made a cage for the spikes and finally resolve my black spot issue.
I had to make some smoothing group to get a good normal map.
Now the black spot is gone and the normal map react correctly.
low_seb, my vertices are correctly welded, I don't know what produce this.
I had to treat my spike like hard surface model (actually they are
allaze-eroler, thanks for the link, I'll take a look at it. Actually I knew it before but forgot about it
OtrickP, thanks for the feedback you are certainly right but I don't plan to tweak the modeling for the moment, I want to learn the basic of baking, texturing and low poly modeling first.
Don't tickle my perfectionism I have to move forward
Thank you Vizjerie.
So here is where I am for the moment, redid the uv once again, tweak my low poly and made some cages. After many baking test here is where I am, still having some small issues but I think I will paint them in photoshop.
Unfortunatly I still don't know what cause the seams issue with marmoset.
Btw I'm still working on her, I tried different method for texturing and now I'm going for hand painting in photoshop. I was not satisfied with using pictures only so I wanted to tried the hand painted way.
But I have some issues with my painting, I can't get the crisp result I see on the amazing work showcased here.
I don't want to learn the magic trick that turn you to Texturing master in one day as I know that practice can only be the way to go.
But my painting is kind of muddy, even if I get the way of blending with photoshop, or at least the basis, I can't get a really crisp and clean painting.
Do you guys have any tips for me?
Here is what I'm doing, just for the scales trying to get them as clean as possible.
Start with a flat dark gray, let's say 25% or so...this will be your shadow tone, and from there you'll have to add lighter grays to create the main big forms, and then move always a little more into smaller details...more or less like sculpting...start big, end small.
Note: keep in mind that if you're going to have normal and specular map, these maps are going to contribute to the creation of the forms and volume of your model, so you'll have to paint the diffuse considering also those factors.
When you'll have a good value base and you decide to put down some colors, remember to now just use flat colors, but make them slightly change in Hue and Saturation along with the value changes that you painted already.
If you have a few bucks to spend i suggest you this video tutorial series on Hand painted textures
I'm actually using AO, Normal Map and cavity to help me paint my texture and even photography.
But I'm painting most of my texture and use these map and picture to improve the overall result.
Timotronprime, you are right the tails lack of details, I'll try to improve this on the texture.
Shiskebab, I didn't even thought about it. I'm currently using Mudbox and Photoshop, but it is a good idea to use Zbrush on the high poly mesh. I'll try that next time.
Here is my progress on the texturing, learnt a lot and I enjoy the process.
I was thinking about the process of texturing for game and I'd like to tell you what I think it is to see if I understand it right.
From my understanding the shader for game are less complex compared to precalculating rendering.
Where, with precalculated, you have complex shaders that represent how the light is reacting, in game you only have your diffuse, specular, glow and normal map to reprensent the quality of your materials.
So the diffuse map must have all the usefull information baked in, the color variation that can occur in different lighting condition, the SSS and so on should be in your diffuse texture to make your materials readable and recognizable.
At least that's what I'm thinking of when painting my diffuse texture. But I don't want to exagerate too much to not fight against my normal map or to not make it too fake by painting too much light information in my diffuse map.
I'll stop there or it will be too long but that's at least approximativly why I wrote down on a piece of paper to help me understanding this process.
Correct me, be harsh and whatever if I'm saying bullshit.
And here is what I did with my texture, comment and crits are welcome and encouraged
Sure! I didn't say you don't have to use AO, Normal and cavity. There are various ways to handpaint a model, from using only diffuse for all the light informations, to a mix of normal, diffuse and all the rest. Of course according to the method, you have to balance your painted diffuse. The video i linked to you is just to give you an idea of how to handpaint something, and what tricks you should use to make it more visually interesting. Then if you wanna use AO and normals, the same theories still remains.
About the texture you've done, it's a good starting point, but it's definitely too dark. you should try to differenciate the various materials (flesh, bone plates,) in color and value. At the moment the look all too the same value, except the white part down, that looks quite weird. I think the brown parts should be a little more light and saturated especially around the face.
I would leave the lighter color u used in the bottom just for all the claws and spines that are all around the body, so to make them stand out from the rest.
Check some references online, and you'll notice that the color scheme, is different than yours.
*EDIT: an image to explain the color scheme.
I said that I was misunderstanding hand painting technique because in the video he saids that hand painted mean baking all the light information in the diffuse without any other maps.
For me hand painted was just the opposite to projection painting.
About the color scheme, I'm not using the same as the concept, the white belly is something I found on scorpio, they have some kind of white flesh under their shell.
But I changed the contrast and tried to make it more readable.
I will pass on the specular because I want to learn it too and will go back to the diffuse if needed.
I'm quite happy with the result, not the best you can find that's for sure but I'm really not used to do any texturing work so I loved diving in this new world.
Now I have to learn how to make a good specular map.
Here is the current wip.
So here it is.
I wanted to ask you guys how do you deal with the seams when using this 3/4 mirroring trick. I had some difficulty to clean the seams.