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Doom 3 skinning question

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#1

Hello, here’s a question for anyone messing with game development, and Zbrush was used in making Doom 3 according to Robert Duffy, so someone must know some details. Anyway I have taken the fat zombie into Max using der_ton’s MD5->3dsmax importer, and then exported as an .obj file for import into Zbrush. The fatty_d.tga from Doom3 was converted to a .bmp and matches up to the UVs for the model, except it seems to be for the model without a wrench. You can see the results:

fat zombie in Zbrush.jpg

The problem is the part of the image with exposed intestines is mapped onto the wrench. I can’t find a md5 mesh for the zombie without a wrench, or a skin that includes the wrench, so I’m confused about what the Id guys have done here. Where is the wrench-less fat zombie? Very confusing. On the plus side Zbrush seems to read the mirrored face texture just fine (one half of the face is on the texture).

#2

hi, sorry i dont have an answer to your question, but i was wondering if you could post the obj. file and the bmp. of that zombie, i’d love to check it out. also have you tried applying the texture as a displacement or normal map?

#3

On the plus side Zbrush seems to read the mirrored face texture just fine (one half of the face is on the texture).

ZBrush2 will read the mirrored faces on imported models fine, but go ahead and use Projection Master and attempt to paint on those mirrored faces and let’s see what happens! You will get one of three results:

1 - Strange and unexpected results to your paint once you drop the object to the canvas

2 - ZBrush will hang and then eventually crash after dropping your object to the canvas

3 - A combination of #1 and #2: First strange paint results after dropping the object to the canvas and then ZBrush crashes

The result of this is that it makes ZBrush2 about useless for painting skins on low-poly models that have overlapping UVs. The only way to do it is to delete the parts of the model that are to overlap on the UV map (such as half the face, etc), import the model into ZBrush, paint, export, copy the missing parts, mirror and re-attach to the model.

Frankly, I wish ZBrush2 allowed for a painting on section of the model with overlapping UVs. All it would need to do is mirror the stroke on the overlapping UVs like it is done in other programs.

#4

im pretty sure that the wrench is supposed to reference another texture. since zbrush can only use one texture at any given time, what you see there is the wrench using the same texture as the character is using.

maybe im wrong. but it would make sense.

zbrush also doesnt let you work with multiple objects simultaneously, where each has their own texture. when you imported the model with the wrench it could have been made up of several objects, but when you import that obj file into zbrush it will be treated as a single object. and we know that we can only have one texture per model… so IF the texture you have there is correct for the model. then the wrench is using a separate texture.

#5

Just load the Doom file into Max again, throw out the wrench and export only the Zombie Model as an .obj - I’m with ambient-whisper, I’m sure there’s a seperate texture for the wrench.

#6

To create maps where for technical reasons you must have overlapping UV coordinates, simply hide the overlapped region. ZBrush will ignore it when doing all calculations, and so the overlap will never be an issue.

Regarding the wrench itself, yes: There most certainly is a different texture being referenced there.

#7

Was there a reduction in the amount of polys when your did the format conversions? cause the zombie just looks so much ‘smoother’ in-game? if it didn’t lose any and it’s just as smooth in-game then why does it looks so low on polys here…anyone care to explain?

#8

normal maps applied to the model :)+ zbrush shows models faceted, while doom3 shows them with a smoothed material.

#9

well, i figured that normal maps partly were to blame for it looking kinda faceted…but this thing about d3 applying a smooth material is new to me…can you just elaborate a little more on that?

#10

Hi!

There are 2 (or more) groups for that model…

one for wrench and one for the big guy…

Open the OBJ file into wings 3d, and select the wrench group, and delete it.

Wings is pretty cool about things,… it will leave the rest of the UV maps intact (Most of the time)

This is probably possible in 3ds max also… just dont delete any parts of the large gentleman.

after your surgery, re-export the model into OBJ…

Hope this helps…good luck! :sunglasses:small_orange_diamond:+1:

BTW your best bet is to just re-paint the 2d texture… some parts of the models have been mirrored to save texturemap and detail map space… (this is why there is a visible lighting seam on some of the Live human charictors forheads when useing a lame graphics card with the Ultra low res textures settings…)

#11

Every game out there smooths the geometry normals. Thanks to god that the “flat shaded polys in games” times are over… :slight_smile:

#12

really? i had no idea…and this technique adds no polys? Is this sort of like drawsmooth in zbrush? i know this isn’t the proper forum, but can anyone go a little more into detail about how that works in-game? i had no idea that this existed.

#13

actually there really isnt any smoothing involved in gourad shading… gourad shading figures out the lighting at each vertex and then AVRAGES the resulting color across the connecting edges from onevertex to the next…

PHONG shading avrages the normals between the vertices… however phong shading is not in many games… and i’m not sure if it’s supported by hardware

http://computer.howstuffworks.com/question484.htm here’s a short blurb to help out…

while gourad shading will not capture a highlight if it dosnt hit a vertex exactly on the vertex, phong shading looks nicer on lower poly models because while they have less vertices all the normals are still represented by the interpolation