You want to put a model (you imported with m3 exporter) to Art Tools?
Until Leruster fix the exporter to be totally compartible, follow this:
m3 exporter part:
FIrst, import with fps = 30. Not 1000 as default.
Then write down the names of all animations, and their start/end frames. For example: Walk, start = 33, end = 63.
Also, check model's materials. What textures are used, what blend type, what specularity/emissive multipliers are. You will need it in art tools.
Save the model as .max, and open it with Art Tools
Art Tools part
To remake the material(s), create sc2 standard material, and add the diffuse/specular/normal maps, set the specularity/emissive multipliers, pick the blend type. Then drag the material to the mesh. Sometimes it requires some more tricks, to make the material look exacly like it supposed to. Read Materials part of Art Tools documentation to understand what to do, it's not that hard.
To remake the animations, open Art Tools animation floater, create the animations with correct names and type the start/end frames you wrote down.
To scale the model 100 times up, which is required for m3 exporter ->Art Tools transition, fo Utilites tab -> More -> Rescale world units -> type 100, ok.
The blue helper boxes you see on/around the model are the remnants of the attachment points. You can create new attachment points, ctrl+a (both, position + oriantation) them to those helpers, and link them to the helpers. Or remove helpers and link your points to the bones those helpers were attached to.
Also, you can create fuzzy/tight tests, target/shield volumes and bound sphere for the model. For more information, check Art Tools documentation.
There are images for the material remaking part:
Press M, there you'll see materials, some of them are black, and "missing". At least if it's the version of max you haev only art tools installed for.
In common case, you can create a new material and define it.
First, press this button:
Pick the SC2 Standard Material:
Click on each of diffuse, normal and specular maps, and pick the xxx_diffuse.dds, xxx_normal.dds and xxx_specular.dds textures for them, where xxx is unit name.
And if you are intrigued, but it's your first time you hear about the subject of this thread, there are links: