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View Full Version : Looking for some help from ay 'realtime' guys



gordonrobb
03-12-2015, 04:31 AM
Hi, I'm looking to model the Power Loader form Aliens. I have made the decision that I'm going to predominantly use DDO to texture it, and therefore, have decided on a perhaps convoluted modellnig route. I am doing the modelling in ZBRush, just using dynamesh and booleans etc to get a high poly, high detail part. I then want to create a low poly (i am most comfortable doing this in Topogun). But I'm kind of stuck when trying out the normal map creation.

I want to be clear, I'm not trying to create a low poly, game res type mesh. Just lo enough to animate, and perhaps render in Unity (mainly to play). The main reason is to have a low-ish and a normal, to get the best out of DDO.

My questions are....

1. If I have rounded edge, should my low poly have a bevel or perhaps be on the edge.

2. When I create my low poly and export it for use in xNormal, should my low poly have smoothing on?

3. When I render, should my low poly have smoothing on?

4. When I have a feature that is too big to just be on the normal, should I do topology that is connected to, or separate from the main body of the piece?

Basically any advice any experts in this field can offer, will be really helpful.

One example of a part is this...

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Surrealist.
03-12-2015, 11:16 AM
The main thing you need for this is a curvature map. But don't use that in dDo directly. It is something I have been trying to get sorted myself and finally figured it out. The problem is because when you bake a normal from the high poly to the low poly there is nothing to tell you where the edges are.

I have been using a subpatched high poly to bake down to a beveled low poly. In your case it depends. You could always retopo a subdivision surface version for animation and rendering. But either way you go, you want to take the "low poly" into xNormal, yes, have the smoothing set to the default 89. That should work, if the LW object exporter supports that. I don't remember. But if you don't you'll get undesirable faceting in the map.

Then there are some setting in xNormal to be aware of. Main one is distance in the Curvature map. If set too low you'll have again faceting showing up from the High Poly version. Last one I did I had it set to 3.

And this brings up another complex issue. That is you should ideally have a separate version of your meshes for baking the curvature map, Basically one that is exploded. I guess you can do this automatically in Zbrush. But you want to explode both High and low poly meshes. Just to separate parts that are near each other to get a good clean map. Images attached.

Then when I get a good clean curvature map, I take it unto Photoshop and use a curves adjustment layer to bring out more contrast. I then save this out and load it up and make a Normal map out of it with Xnormal. This will be much more useful for getting edge scratches and so on from dDO than just a normal map. You can use this instead or combine it with a detailed normal map. Depends on the scupted detail. Of course then dDo will export all of your maps, normal and so on. The curvature is just a process to get a good normal map with edges.

The attached images were done with this technique. (I had to tone down the scratches for the client)

gordonrobb
03-12-2015, 11:57 AM
Yeh, I've used that method of creating a normal from a curvature map. My issue is how to get to a good topology from a dynamesh one. Got a bit fed up with it at the minute. Might just build it in subD instead :)

Surrealist.
03-12-2015, 12:06 PM
If using Dyamesh I just retopo a subD version. Dynamesh for free-form creativity mainly.

gordonrobb
03-12-2015, 12:26 PM
Yeh, hadn't really thought of creating a subd version with retopologising. Might try that. Thanks.

gordonrobb
03-13-2015, 07:12 AM
OK, after hours of messing with different versions, I think I've settled on a process....

1. Model in Dynamesh (creativity unleashed) :)
2. Basic mesh in Topogun
3. Tweak mesh in Modeller to make it SubD-able
4. UV
5. Create Normal and colour ED
6. Fire it through DDO
7. Render in Octane..

This is that, textures took about 30 seconds to tweak.

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djwaterman
03-13-2015, 08:39 AM
I've been avoiding trying DDO because I thought you could only use a low poly mesh, are you saying you can put a sub-d mesh into it?

gordonrobb
03-13-2015, 09:10 AM
The programme will work with a high poly mesh, as long as it is UV'd. You just have to create a curvature map yourself. There are a few good threads on the Quixel forum about doing that. Short of that, I was not really distinguishing between lo poly and subD as I see them as the same. In xnormal or DDO then just don't look subdivided. But I created the texture, and then loaded into LW, and it lined up fine. May have to check your UV map is set to Sub Patch, appart from that it was fine. I think.

However, as is obviouls by my question, i am no expert :)

Surrealist.
03-13-2015, 10:05 AM
@DJ, Actually the mesh has nothing to do with dDo directly. It is just a program that uses maps to generate textures using various masks with automated scripts and some clever programing to produce a shader profiles which you can choose base on your target rendering solution. There is a previewer that you can load a mesh into but it is a separate program more like the old viper window that gets updated in real time.

Where the mesh comes into it is in baking maps to use. As far as loading a mesh into the viewer it can be anything. But if you want to preview a subD mesh, freeze it and apply smoothing so you don't get faceting in the viewer. It won't do subdivision surface rendering like a 3D app.

A lot of the work I do is going from a high poly (Zbrush) mesh and baking to a sub D cage for rendering.

@ goronrobb, looking real nice!

gordonrobb
03-13-2015, 10:43 AM
@ goronrobb, looking real nice!

Cheers..

DCjr
03-13-2015, 12:08 PM
That looks great! Nice job.
FYI, Adam Gibson has some tutorials on using DDO and Lightwave. I was thinking about getting myself.

gordonrobb
03-17-2015, 01:59 PM
OK, thought I was finished with this question.

In this bit, I've made the main part, and the details are seperate bits. I'd quite like to make them like that in the low poly version as It'll be easier to do the topolgy clean and it'll be easier to repeat some of the bits.

Problem is I can't figure out how to do them separately but have the bits interact form a normal map/texturing point of view.

Any advice folks?

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Surrealist.
03-17-2015, 03:46 PM
I think I know what you mean but explain it another way, you want to reuse a material set up over several separate parts with separate images?

gordonrobb
03-17-2015, 05:00 PM
Not quite. In the image I've attached, although this is all one bit of complex mechanical machinery, the bits in different colours are different pieces. that's the way I've made them, and they way the actually are I guess. When I retopologise them, I want to retop them as seperate bits of geometry, so in that image, there will be 4 objects. I'm happy about how to retopologise them seperately, but how do I do the normal maps in xnormal? I'd ideally like them all to share a texture, so the UVs for each bit will be distributed over UV space, but how do I achieve that if I'm calculating the normal's seperately for each bit. Is there a way to combine the 4 normal images into one? I'm not sure if I'm making this more or less confulsing :)

Surrealist.
03-17-2015, 06:38 PM
Yeah that's how I do it. I mean if you want to do separate bakes for each part. Then combine them in PS first. Yes. You don't have to. Just depends. Many times I'll just build the whole model first, UV unwrap and bake. But you can do it in parts as well, which is how I am doing my current project. From there it is a matter of deciding to wait and do one dDo session or build one iteratively, which involves constantly reimporting the maps and re-rendering. As for the final object it can be separate for animation if that is what you want, but the version for preview in 3Do should be joined as one.

gordonrobb
03-18-2015, 02:43 AM
I feel that I may be confusing the issue. This 'bit' of the model is an upper arm (closest anatomical comparison). It will be one piece of the over all model. If it was a game model, I'm sure it would not be textured seperately from the rest of the machine, but it's not a game model. My issue is that in this one piece, I have details that I want to be not joined from a topology perspective. So the plates and the mechanical shape in the image above, it is easier for me to have them be non connected topology, and have the main body of the arm just flat underneath. My issue is how to then back the textures for these seperate bits. If I make all the seperate bits of geometry, as one OBJ file, and back in xNormal, it doesn't like it. But, if I back them seperately and then combine them before importing this piece into DDO will it find (for example) where one piece joins the other, so that it can put dirt in the cavity?

I may have to do some tests, or upload a test piece to show want I mean, as I'm not sure I'm explaining it right :)

Surrealist.
03-18-2015, 03:54 AM
If xnormal is not liking it it is not because of the separate pieces. There may be some other issue, if I am following you. I do this all the time. So you should be able to bake it as one obj that has separate meshes. The example I showed on the first page was such a mesh. Or do you mean there is some other issue with the baking? Trying to figure this out with out the mesh or some images is more difficult. I am sure I can help you solve it if I have all the information.

gordonrobb
03-18-2015, 09:09 AM
OK, here is a zip that contains 3 seperat hi res bits that intersect. An the 3 part OBJ, with UV, that I want to use in xNormal. I tried loading all 3 high res in, and then using the low res, but the UV was a mess.

If you could take a look and let me know what I'm doing wrong, that'd be great.


https://dl.dropboxusercontent.com/u/9253982/Zbrush%20Stuff.zip

Surrealist.
03-18-2015, 09:25 AM
OK DL now, I'll have a look at it.

gordonrobb
03-18-2015, 09:52 AM
Cheers.

Surrealist.
03-18-2015, 10:10 AM
OK, you mean the error message saying the UV is pointing to a non existent vertex? That is what I am getting. That is the low poly mesh. I loaded it up into Blender and exported an OBJ and it seamed to clear it up. After that the bake works fine.

gordonrobb
03-18-2015, 10:13 AM
I didn't get that error message. I got a rubbishy normal, with lots of errors..

Can you post the normal map you're getting it to generate?

- - - Updated - - -

Here's what I was getting...

Surrealist.
03-18-2015, 10:31 AM
OK this is what I am getting.127537127538

Settings:

127540127539

gordonrobb
03-18-2015, 10:59 AM
Actually, trying it now, I'm getting the follwoing error....

Unhandled exception

That tells me a lot - not! :)

Hmm. So did you load all three hi res objects in, and the single lo res one, an just run it at those settings?

Surrealist.
03-18-2015, 11:30 AM
Yeah.

gordonrobb
03-18-2015, 11:42 AM
I notice that I have a different version of xNormal. I'm downloading the latest version, even though the version I have is newer than yours, that might make a difference.

gordonrobb
03-18-2015, 11:58 AM
Hmm. That still just gives me the same error. Aaaargh!

Surrealist.
03-18-2015, 10:52 PM
Hey sorry to hear that. Did you get it sorted? Maybe try a different Renderer setting?

Also there are other options for baking:

Blender of course.

Well you are using Zbrush you could bake the normal there. Any other apps you may have like Modo, Mudbox, 3D coat?

Often if I can't sort out baking I try another app.

gordonrobb
03-19-2015, 02:06 AM
Sorry mate. I had to leave it last night. Will get back to it this evening.

I'm more concerned about the fact that the mesh has an error that Zbrush and Lightwave Modeller can't see, and therefore fix. It's nothing in the case of this little text bit, but if it was to be the real piece, that I'd spent hours doing the retopologise on, I'd be goosed. :)

How did you fix it again?

Surrealist.
03-19-2015, 02:47 AM
I imported the obj and then exported it as an obj again. Using Blender just for convenience on my end. But I suppose you could do the same in LW. I have LW but the dongle was not in ATM.

gordonrobb
03-19-2015, 03:13 AM
Yeh, I tried importing and exporting it in Modeller. Also trie opeingin the LWO file I used to create the OBJ file and exported it again. I am fairly sure it's a problem I created in the UV, however, as I don't know what it is, or how I created it, I'm concerned :)

gordonrobb
03-19-2015, 03:15 AM
btw, to answer your previous question, I found the ZBRush normal maps that get created are not as good as xnormal, and also, to use ZBRush I have to have the high poly made from the low poly (which involves projecting the detail on to the low poly versoin as you sub divide. This can be done, but I find it hit and mis with causing jaggies etc.

I'll settle on a workflow I'm sure :)

- - - Updated - - -

Thanks for all your help on this by the way. It's an area I've been meaning to get more into for some time.

Surrealist.
03-19-2015, 03:58 AM
Yeah I follow you on the maps in Zbrush, I think I ran into similar things and it is more of a convoluted workflow. My baking choices are Blender, Mudbox and Xnormal currently as well as Maya. Sometimes the AO maps in Xnormal look horrible so I go to Blender. Baking is a whole art in itself though, just trying to get it right. It took me a while just to figure out the process of using curvature maps.

What I did was just put some test bakes into dDo and loaded each mask type to see what the masks were picking up. I kept working on that until I was getting the masks it was making from my maps to look similar to the thumb examples they give you.

Hope you can sort out the object. I don't think it is anything you are doing wrong. It is probably a bug. Mudbox/Maya workflow has a similar bug where it reports that the maps are incomplete in Mudbox and in Maya they are all there in Maya and in Mudbox. And you can paint just fine. But the waring comes up. I have not figured out why it happens. This may be what is happening in the case of Xnormal. Something in the file the way it saved is not right that it does not like but other apps are fine with.

If it is not working to convert in LightWave then perhaps try doing it in Blender.

gordonrobb
03-19-2015, 02:59 PM
OK, found the problem. I had a lot of duplicate polys. Had to merge and unify. Sorted now, and ran the normal ok. Chucked it through DDO and this was the result. One with the geometry I had, and one with a very quick attempt at making it subD. Happy to move forward with this process. Thanks a ton for your help Mr Surrealist :)
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127551

Surrealist.
03-19-2015, 03:42 PM
Glad to help. Lookin' real good. :)

I wanna see the rest of it when you get it finished.