8 réponses à ce sujet

[A2Buddha]

Well, I thought I had made a breakthrough in texturing.  I was going to take a low poly model (obj) straight from the game and then take a separate high poly model (obj) that I had zbrushed up, load them both into NVIDIA's Melody, and then generate a displacement map that shows the difference between the two.

However, as with all things that sounded too good to be true, Melody just keeps on crashing.  I've managed to generate normals successfully, but any time I try to make a displacement map, it bombs.

Anyone know of a program that will basically allow me to compare two models and output the difference as a displacement map?

[ChewyGumball]

were both models uved?

[tazpn]

You could try xNormal though I'm not sure it does displacement maps like you want. It does Normals and Height maps as well as a bunch of to others I've never used and heck if it doesn't you might convince the author to do one.

[Nodrak]

Are you sure your meshes are set up correctly? Some auto normal/displace generating tools will fail, crash, or give errors if the meshes intersect, or have areas where the 'rays' do not complete their 'trace'. I have had numerous issues with Obj files having their verticies become unwelded, which may or may not be an issue here.

[A2Buddha]

Chewy, they were both UV'd -- at least I assume they are as they both use the same texture, and I've successfully painted on the high res and used that texture on the low res.



Nodrak, ... , that's an open ended question. It's a good one, and I don't know for sure that they're set up correctly. I will say that Melody is able to generate normals for the models, so that's not bothering the program. But when I try to do displacement -- boom, boom, pow. I also don't think that they've come unwelded, but I'll check that.



From what I've seen, Melody has a history of crashes, and it's no longer supported by NVIDIA. Of course, I can't put all the blame on them, as there are about 5 check boxes or selections that I actually understand, and about 50 that I don't.



Tazpn, I'll take a look at xNormal -- thanks for the link. And as ever, thanks for your command line tools, or I wouldn't even be able to pose myself problems like this!

[A2Buddha]

Allow me to illustrate what I'm trying to do in hopes that it will spark an idea with someone:



So I've got two models. They're in two separate files. However, Model_2 is just a copy of Model_1, retaining the same UVs. I pulled it into zBrush (for instance) and smoothed it out, and I can repaint the diffuse texture there and it works fine on Model_1 in game.

What I'm looking for is a displacement map that shows the difference between the two:



I then take the displacement map that I generated and apply it to the low poly Model_1 which makes it take on the same look as Model_2 in game (in other words, it hides the green ring around the middle of Model_1). Is there a tool that will allow me to do that, or is it impossible?

[A2Buddha]

Alrighty... perhaps a new question based on a PM that I got. IKe0s was kind enough to ask me why I was looking for a displacement map instead of a normal map. So here's part of my response to him:

Well, I'm kind of at a loss as to what exactly the engine is doing with the _n textures. They're not traditional normal maps, as they're not in RGB with each pixel being a combination of RGB that adds up to a vector with a value of 1. I suppose they could be parallax normal maps, which are greyscale.



Either way, whatever the engine is using, I want to produce something in the right format that will morph or light the object in such a way that I can get rid of seams. I figured if there was a way to take a modified model in high poly with no seams and make a normal that is calculated off the base low poly model with seams, you MIGHT be able to make the seams disappear. Might.



Then again, by the time I figure that out, tazpn may complete his tools and I'll just be able to import a whole new model...

So what exactly is the normal map used by DAO? It's greyscale, so it's not an RGB normal. Is it a parallax normal? What rules apply to generating one? What's the difference between generating an RGB normal and converting it to greyscale or just making a greyscale one directly? For that matter, what would I use to make a greyscale normal? Can I produce them in zBrush?



Le sigh.

[ChewyGumball]

The _n files are not greyscale. They are in fact rgb with an alpha. Infact, if you fill the blue channel with white you get basically a regular looking normal map.

[Nodrak]

Doesn't the spacial coordinate system used also effect how the normal map looks? Ie, Tangental Normal mapping, vs world space normal mapping?  (or is my normal mapping knowledge a bit dated now >.>)

Modifié par Nodrak, 29 novembre 2009 - 06:17 .