View Full Version : MDD files and their usage!

10-01-2014, 02:42 AM
Can someone please explain when of where MDD files are meant to be used and how to create and use them in the best way?

I am a little lost here and wonder if they at first are meant to be used as proxies and secondly as final characters/objects for rendering?


10-01-2014, 03:11 AM
Can someone please explain when of where MDD files are meant to be used

f.e. when you have to send scene with animation to other package. Bones, motion modifiers, deformations etc. must be baked.

f.e. when you have to render on render farm. Reading vertex positions from MDD is fast, while recalculating motion modifiers, deformations by render node for every frame might be too slow, or not possible (if one frame depends on what happened in older one).

10-01-2014, 04:27 AM
In a simple way, they are used to take all the animation info that relates to the mesh geometry, the bending and deformation, movements such as bullet simulations, and export all of that but without bones or calculations, so that the other application imports a file with all the geometry moving around magically without bones or anything. That's my dumb_ss explanation.

10-01-2014, 04:41 AM

10-01-2014, 05:05 AM
imagine an MDD containing all movements of an animation baked to each single vertex of the meshes in the scene for each frame. at this point (!) each coordinate has a position information for each frame. this way you can transfer mesh and displacement information for each mesh coordinate to any other application using MDD files. you can see it also as a coordinates "cloud" which is applied to geometry over time. hope this helps?

Ryan Roye
10-01-2014, 05:55 AM
MDD files are also used in some animation pipelines where the person handling the Lighting, Environment and rendering needs to be working with the final assets. Unlike with animation controlled by movements, bones and displacements, MDD files can be saved out and referenced by any number of .LWS files. This is extremely relevant to production pipelines that involve heavy compositing workflows.

This means if you have 5 animators all working on a single scene, but working with different elements of it, they don't have to be stepping on eachother's toes to all work on it at the same time and give the render dude something to work with, even if their "final version" files consist of separate .LWS pass scenes.

Oh, I should say in Lightwave, you'll always want to save out an MDD file with the object using a subpatch level of 0 if you intend to re-use the motion within Lightwave. You should only freeze a mesh (remove subpatch and replace with "face" polygons) when absolutely necessary as MDD files can get huge with dense geometry.

10-01-2014, 10:15 AM
MDD's are mainly useful for network rendering and for transferring animations between different 3D packages. Because your deformations are baked, you will get the same exact deformations across all machines or any 3D package.

This can apply to many types of animations. For example, if you're using bones for character animation, the deformations may vary between different programs because of the differences in how each program uses IK or applies deformations. Procedural deformations and dynamics may also look different between programs, and may even render differently across a network using the same program. MDD insures that you get the intended deformations/animations from frame to frame regardless of the package or number of computers rendering the scene.

Also, because an MDD is 'baked', it can simplify a scene by replacing calculation intensive animation processes. This can be especially critical for rendering.

Of course, you should keep you eye on the size of your MDD files--if you allow them to get too big, they may possibly negate the benefits. You can save a lot of memory by baking only the range of frames you will render.

MDDs can also be very useful for editing the animation more easily than using conventional animation tools. Some MDD readers will allow you to offset animation or time stretch and remap the motion. If you use nodal, you can even mix and blend certain MDD animations. If you want to 'sculpt' your MDD over time, Chronosculpt is designed for this. Some of the FX tools will allow you to edit your MDD within Layout. (Useful for modeling 'to camera' for camera mapping or tweaking objects like terrain.)

BTW, using the Metalink tools, you can attach items to an MDD animated object. I've often had to do this to attach hair guides to a character animated in Maya but needed to be rendered in Lightwave.

It's a very flexible and powerful tool. If you do a lot of animation and FX work (especially dynamics), it's good to get familiar with it.


10-01-2014, 11:48 AM
MDD files are containers, they contain vertex lists for each frame of your animation. Nothing else, only point coordinates.
If you open up an mdd file with a hex editor and change the view mode to floating point you will see your models coordinates.
That simple.

10-01-2014, 01:39 PM
Thanks, you are the best guys ever!

10-01-2014, 05:07 PM
adding a flock of thousands of instanced daz figures doing there thing of the dancing queen? and all that with bones?, well..easier on the memory to scan the figures and only use the mdd file, plus with dpont instancer you can ofsett the starting of the dance on some of them.

thereīs also a special moment if you want to cloth deform a sort of displacement on some trapcode alike form but not only with procedurals, you want to be dynamic with a wind turbulence to deform it, and finally render it with tiny sprites..similar to a particle
field, you canīt have hypervoxels sprites work on that clothfx dynamic twirled shape/vertexes....unless scanning it to mdd...the effect is similar to this...


But this was just procedural displacement so it works with charm with hypervoxels, but if you displace it with clothfx and wind dynamics..you need to scan it first before hypervoxels follows all the vertices correctly.