FS2004 MakeMDL 1200 Animation Limit Bypass

[arwasairl]

Hey all,

As you all know, MakeMDL has a 1200 animation limit. However, the sim supports more than 1200 animations, so to get around this, I patched MakeMDL.

In the below example, I have this object which contains 2496 animation records in total. Unpatched MakeMDL will not compile this and give an error.

However, with patched MakeMDL, the model will compile and will even render and animate correctly in sim.

Due to the questionable legality of the rehosting of copyrighted MakeMDL files, I am unable to post the already patched EXE, but you can patch it yourself relatively easily with these instructions:

First, expand the PE by adding a new section called .patch. I am using PE-bear to do this. Set the raw size and virtual size to 1000 and ensure that the section is at the end after the .rsrc section. Save this as a new executable, this will be the one we will use to patch.

Next, create a new animation table and patch all instructions to use the new one. The reason we cannot expand the old one is that the old code initializes an array 1200 indices long, since it is explicitly defined in memory, we cannot change this value easily. This new method instead dynamically allocates the table in the heap.

The address I am using are all in VA. Raw file offsets can be calculated by subtracting the VA address by the base image address (0x400000).

To create a new animation table, navigate to 00502000 and paste this code at the start. This code is already assembled and can be used without creating a flat binary:
53 51 52 57 8B D9 A1 A4 20 50 00 85 C0 0F 84 0C 00 00 00 39 1D A0 20 50 00 0F 84 35 00 00 00 89 1D A0 20 50 00 68 00 40 00 00 E8 91 45 F0 FF 85 C0 0F 85 08 00 00 00 8D 43 04 E9 15 00 00 00 A3 A4 20 50 00 8B F8 33 C0 B9 00 10 00 00 F3 AB A1 A4 20 50 00 5F 5A 59 5B C3 90 90 90 90 90 90 90 50 52 8B CE E8 97 FF FF FF 5A 59 89 0C 90 FF 06 E9 0E B4 F2 FF 90 90 90 90 90 90 90 90 90 90 90 50 E8 7A FF FF FF 8B E8 58 8B 75 00 E9 12 C0 F2 FF 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 00 00 00 00 00 00 00 00 00 10 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 89 F9 E8 39 FF FF FF 89 C6 3B 1F 7D 48 8B 0C 9E 85 C9 74 37 81 F9 00 00 50 00 72 2F 81 F9 00 00 FF 7F 73 27 8B 01 3D 00 00 40 00 72 1E 3D 00 00 47 00 73 17 8B 50 14 81 FA 00 10 40 00 72 0C 81 FA 00 B0 44 00 73 04 6A 01 FF D2 C7 04 9E 00 00 00 00 43 EB B4 E9 B3 B2 F2 FF 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90

You now must hook into old animation table calls to use the new one. There are 3 locations where this call must be hooked, at 0042D47D, 0042E09D, and, 0042D3AD. Additionally, we need to patch 2 checks to go above 1200 animations, at 0042D409 and 0042D42A.

For the patch at: 0042D47D, change bytes to:
E9 DE 4B 0D 00 90

For the patch at: 0042E09D, change bytes to:
E9 DE 3F 0D 00 90

For the patch at: 0042D3AD, change bytes to:
E9 0E 4D 0D 00

This covers the calls and our new subroutine will now hook the old table pointers.

Finally, patch the two animation checks at 0042D409 and 0042D42A.

For the patch at: 0042D409, change bytes to:
81 3E 00 10 00 00

For the patch at: 0042D42A, change bytes to:
68 00 10 00 00

Save and assemble your changes. You can now use MakeMDL with up to 4096 animations. It is worth noting that I am not sure what the exact "hard limit" of animations there are for FS9, but it is certainly a lot higher than 1200.

Below are disassemblies for each patch.

Thank you for reading

 

[rhumbaflappy]

A nice solution to an old problem.

 

[arno]

Hi,

Interesting to see that that after so long people still make workarounds for MakeMDL.

I never tried to export objects with that many animations, but what kind of workaround does your patch add? Does it change the ASM code that is written?

The animation length limit can also easily be "worked around" by changing the ASM code and earlier this year I did implement into ModelConverterX to do that automatically.

If the animation limit is similar it might be worthwhile to code that in ModelConverterX as well for people that are not confortable with patching MakeMDL .

 

[arwasairl]

Hi,

Interesting to see that that after so long people still make workarounds for MakeMDL.

I never tried to export objects with that many animations, but what kind of workaround does your patch add? Does it change the ASM code that is written?

The animation length limit can also easily be "worked around" by changing the ASM code and earlier this year I did implement into ModelConverterX to do that automatically.

If the animation limit is similar it might be worthwhile to code that in ModelConverterX as well for people that are not confortable with patching MakeMDL .

As far as I know I think it can be done with an ASM tweak by exporting the models separately into chunks that are under 1200 animation records and stitching it together in the ASM, all it really does is have the Animation Table section of the ASM have over 1200 animation records and BGLC_9 will compile an MDL with this. But I perosnally found it messy to do this and the ULE trick at the same time, and seeing as how the 1200 animation limit is a much more fundamental limit (it literally just checks if animations > 1200, and allocates an explicit array) I found it to be easier to just patch it directly.

 

[arno]

Thanks for the clarification, this seems to be a different limit indeed if MakeMDL is just hard checking for the number of animations.