Game engine 3d models: height/stacking and preventing flicker from far distances

[+swambast 601]

Hi 3D Modelers,

 

I need some help understanding the game engine rendering on 3d objects.  Especially those that are “stacked” in height.  Assume I have the following basic model.  When I stack these models like so, and put into the SF2 Vietnam game I have a very undesired effect.  

 

 

What happens is when you look at the model from a far distance…

• The red box/model begins to shimmer horribly.  
• It looks like the red box is actually moving down the Z-axis into the green box…sort of giving a result like in the picture below.

 

Question:  what can be done to prevent this from happening?

• Would adding another height segment help (like in pic below)?
• Would adjusting the Z-buffer offset in the .ini help (didn’t appear to do so)?
• Would adjusting the pivot points on either model help (experimented with this but not much difference noted)? 
• Other ideas?  What else has worked (other than of course directly extruding from the base mesh)?  Would like to solve this using the proper 3d technique as opposed to other work arounds.

 

 

[+mue 707]

The flickering is caused by z-fighting. In this case the top face of the red box z-fights with the top face of the underlying green box.

To prevent z-fighting issues:

1) Don't put objects on top of (or near) other objects

and

2.) Use only convex geometries.

[+swambast 601]

Wow, only one reply...thanks Mue.  Couldn't handle the limitations of not stacking so thought of some creative ways that I think show great potential but more testing is needed on my end...

[Wrench 9,426]

never been able to 'stack' anything in these games as far back as I can remember doing terrain mods. I know I've tried for years!!!! (unlike the old Fighter's Anthology, where you really could pile things up)

 

Things just tend to "drop" to within each other, probably as Mue says, due to the z-buffer stuff

[+swambast 601]

I think the reason for the lack of stacking is because it would require a different approach to actually creating the base 3d model.  But in fact, IF my testing trials prove out, it would actually result in a more optimized model that should either prevent or limit far distance flicker.  I'm only testing on one model right now, generically similar to the example I've shown...and it seems quite encouraging even with aggressive horizon distance settings  But more to come.  

[+logan4 845]

If you yourself create the 3d model then I would link the upper objects to the base mesh, same like any ground object or aircraft mesh hierarchy, that would keep them on place. If you try to stack something already existing, the answer is already in the above posts I think.

[+Stary 2,426]

Steve, first please check your email, I have found something you asked me of ages ago

 

second, I think it's the simple answer I am affraid -engine limitation -it doesn't seem to do checks on collisions/bounding boxes between non-aircraft objects, so you can have literally ships moving through hangars with no effect seen it myself on badly set up Cuba terrain; alas "we have to live with it"

 

as for the objects the most obvious answer is remodel them the way you want in Max; if you do not have acess to core max file (say it's stock models)  then I can't think of any way to solve it

 

@Wrench: Oh man, FA stacking was awesome!