GMax and LOD's

[stuart277]

G'Day to all
My name is Stuart and I have been working on ship designs for CFS2 using GMax.
At the moment I have been doing some Japanese Destroyers but I have run into a possible problem.
They have a lot of 25mm AA guns that take up a lot of poly's, and as small targets, they do not need too many poly's.
The obvious solution is why use them, however, they do make up the ships armament, however effective hat may be.
I thought about set them up in LOD's so thay can be 'invisible' at distances over 1000m (or so) but I do not know how to do this.
I have GMax 2004 and there is no obvious LOD 'button' as there is in other GMax modules.
Any help would be appreciated.
Cheers
Stuart

[hairyspin]

Not sure where you find an LOD button in Gmax, even 3ds Max doesn't have that until version 2008. You have to build LODs yourself and name them as per the SDK. It's not too hard to simplify a clone of your existing geometry. Good luck!

[Blood_Hawk23]

G'Day to all
My name is Stuart and I have been working on ship designs for CFS2 using GMax.
At the moment I have been doing some Japanese Destroyers but I have run into a possible problem.
They have a lot of 25mm AA guns that take up a lot of poly's, and as small targets, they do not need too many poly's.
The obvious solution is why use them, however, they do make up the ships armament, however effective hat may be.
I thought about set them up in LOD's so thay can be 'invisible' at distances over 1000m (or so) but I do not know how to do this.
I have GMax 2004 and there is no obvious LOD 'button' as there is in other GMax modules.
Any help would be appreciated.
Cheers
Stuart

Stuart!!!

Welcome back my friend.

so do you want the quick and dirty approach or the longer (tough not by much) version.

Take your Kako, that was the first ship we worked on so I'll start with that.

All of the parts that you currently have add this after each name; "_LOD_100" (no quotations)

an example would be the Hull. name it Hull_LOD_100. do the same for all of the parts you currently have.

On the right side where you have the tabs for Create, Modify and so on, select create.

next click the little button that says helpers. we will now make a dummy box. size doesn't matter. just make it big enough to work with.

now you will need to make sure it is zeroed out. make sure the "X", "Y" and "Z" values are at zero.

next name the box Kako_LOD_100.

you should now have all of your parts with the "_LOD_100" extension and a box named Kako_LOD_100. what we want to do now is link all of the parts to the box. how i do it is to select the box and hide it then select all of the parts and unhide the box.

the top bar, under the menu bar, you should have the arrow in yellow/orange selected. next to that on the left are 2 buttons select the one with the 2 little boxes and chains.

now on the right side of the arrow is an arrow with lines. select that check the bock that says display subtree. and click on the Kako_LOD_100. this should take all of the parts and link it to the Kako_LOD_100 box. to test it select the box and move it. all of the parts should move with it. if not undo the move and try again.

by the looks of the model you already know how to link parts. so this is just a refresher.

now you can take and make the next model. you can give the next parts "_LOD_080" or if you want more LODs you can use "_LOD_90" if you want less use "_LOD_075". depending on how much detail you want you can do 080, 060, 040, 010.

As you make more LODs you can go very simple on the modeling and polys. remove the parts that are not needed. make it boxier. so on and so on. at LOD_010. you can go very simple with maybe the hull as a box and the top as a box as well.

you will have to texture them. so either map the sections with the same textures or make a basic one for the smaller LODs. just remember to make sure everything will match up at a distance and transition smoothly. I would use textures and not just materials as any repaints won't match.

after you have made all of the models and named them the correct LOD level you will merge all of them together.

Oh Here is something you will want to do. LOD_100 material start with 00 or 01 in the names of the material. when you do the material for LOD_080 and so on you something like 20 or 50 to start. so if you start with 00 and end at 10 start the next LOD with 20. Do you follow what I'm talking about?

That is so when you merge your models you don't mess up the materials or and mapping on them.

After all of the models are merged you just compile it as normal.

If you need examples I can send you some of the models I've made. If you need more help contact Allen. he is the one that taught me. You can also ask Robert John or the B24Guy. Robert might be busy so if you don't hear back right away don't worry.

You should still have my email. I'll drop you a message so you have it.

Thats is as simple as I can make it. Allen or one of the others might be able to clarify things if you need it.

Take care my friend.

Till Later,
John

[stuart277]

Hi John
Thanks for that.
I got your email and I will check out Allen's info.
At the moment I am not sure about what the difference is between LOD_100 and LOD_90 etc, but I will look into it.

Hi Hairyspin
Thanks for the info.
I do not know what SDK is.

Cheers
Stuart

[hairyspin]

It's the Software Development Kit, as supplied with/for CFS2? I build for CFS3 and the SDK was a download from MS, the SDK for FSX was included with the Deluxe version. It explains part naming, animations, texture format, sounds etc. I would hope the CFS2 guys should be able to tell you where or how to get it.

[Blood_Hawk23]

The easiest way I can discribe it is the _LOD_100 is the full view of the model with the most detail. _LOD_090 would still have alot of detail in the model but not as much as the model its self. the _LOD_010 would have the least amount of detail. it could be just a flat poly or maybe a simple box. all of the part would have that tag for the respective LOD. so in case of the Kako all of the parts would add "_LOD_100". now you have to make a new model for the next LOD (Level of Detail) you could start with _LOD_090, but unles you want to make 10 new models I would start with "_LOD_080" or even "_LOD_075".

check your email i'm sending one of the static models i did. so you can see what i mean.


Hairyspin,
any and all information is welcome. please share any thing you have. i know i could use more on the subject. actually my issue is the textures but thats another topic.

Till Later,
John

[Blood_Hawk23]

I'm using both the FS2002 and FS2004 SDKs. let me know if you need one of them. they have the makemdl.exe for compiling the model. you must be using one of them already.

CFS2 can use either. I use the FS2002 for my simple bgls and FS2004 for the more complex BGLs and MDLs.

You have to do a special setup to use both in one install of GMax.

[hairyspin]

This is the gorgeous Bf109E built by Luca Festari and the late Gerard for CFS3: it's in the Mediterranean Air War (MAW) expansion. I haven't shown all the LODs, but this will give you an idea how the various LODs decrease in detail - see the wireframe shot in particular.









The hierarchy of LODs for the model are usually done as Bloodhawk says above and as a rough guide the poly count should be in accordance with the LOD number. So if LOD100 (fully detailed) has 1000 polys then LOD75 would have around 750 polys, but I have found the LOD actually displayed is decided by the sim itself. To determine which LOD is being displayed I borrowed an idea from bzhyoyo and put a coloured sphere off the wingtip of my own model: LOD100 has a red sphere, LOD 90 has orange, then yellow, green, and purple for the second lowest LOD - the lowest of all is little more than a dot in the sim.





The spheres are removed from the model once I'm finished the LOD work. Oh btw, the LODs are all centered on the same point, unlike the above screenshot: it is very poor form to have a model jump a couple of yards to one side when switching between LODs but it has happened...

The FS2002 SDK can be downloaded from FSDeveloper, as can the FS2004 SDK. Another extremely useful - no, essential add-on for Gmax - is MeshTools 2.5 and its installation and use are described here. To me, the tool for removing vertices cleanly is indispensable when simplifying a model.