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Old 09-05-10, 14:34   #852
Join Date: Aug 2009
Location: Genoa, Italy
Posts: 72
Default Tutorial

Tutorial: How to get a posable XNALara model into Maya and animate it

What you need:
PART 1. Import the model in Blender

We are using Blender as a model format converter and to fix the lamina faces in the model.
In the screenshots I'm using the larajungleshort model as example.

Export the model from XNALara you wish to import in Maya as .mesh.ascii format or you can convert the binary model file with Dusan's converter.

Make sure to copy the import scripts in the .blender\scripts folder inside the main Blender folder. In this example I have the Blender root folder in C:\Program Files, the Blender folder is blender-2.49-blahblahblah

Open Blender and import the model.

Press the A key once to unselect all the parts of the model (if you press it again you reselect all).

We are going to fix the lamina faces present on the model's head as you can see in the image above.

Select with the right mouse button the part of the model (in this case the head) we want to fix. The selected part is now highlited with a pink border.

Press the TAB key to enter into Edit Mode.

Press CTRL + N to clean the lamina faces on the head top

More lamina faces to remove........

Now the model is free from lamina faces. Press the TAB key to exit from Edit Mode then press A key twice to deselect the head and reselect all the model.

Export the model in .FBX format.

PART 2. Import the model in Maya

Import the .FBX model in Maya. I've set in the Advanced Options the units to meters to have the scale factor 1.0

Now the rigged model is imported inside Maya.

HINT: Don't assign any material for now. We don't need longer render times in the playblast.

PART 3. Cleaning the skeleton

It's time of a little housekeeping

A clean skeleton without unused and useless joints make easier to build the IK/FK system later........... Open the Outliner. Expand the blend_root and select all the parts of the model

With the Middle Mouse Button (MMB) drag the mesh parts outside the blend_root

Now expand the armature and the root_ground item in the Outliner, select the root_hips item

and drag outside blend_root with the MMB.

Now we can select the blend_root and remove it with the rest of his useless hierarchy pressing the delete key.

The first part is done.

Now expand the root_hips and remove the joint unused107 with the delete key.

Expand and select the unused003 joint. From the menu Skeleton select Remove Joint to remove it and automatically connect the spine_lower and pelvis joints to root_hips joint.

Fully expand the pelvis item in the Outliner with Left CTRL + Left SHIFT + Left Mouse Button and rename the unused joints. The joint after leg_right_toes is renamed in leg_right_toes_end and the other leg_left_toes_end. It's a Maya convention to rename the end of joint chains with a name with _end suffix.

We'll apply the same renaming scheme with the breast joints.

It's time to clean the arms. We have to fully expand the arms chains in the Outliner. In this example I begin to work on left chain.

Under the arm_left_shoulder_1 joint we'll find a useless joint (in this example is the unused077 joint). Select it in the Outliner and delete it with the Delete key. Same for the unused joint under arm_left_wrist.

The other joints labeled as unused (numbered as 074, 075, 076 and 073) are very important. They help us to avoid the mesh collapse (called Candy Wrapping) when the arm is rotated on the X axes. We'll rename them with the names arm_left_influence_a, arm_left_influence_b, arm_left_influence_c and arm_left_influence_d.

Repeat the same procedure for the right arm.

Now we remove the unused joints from both the eyes. We'll build the eyes aim constraint later.

From the head_eyeball_right remove the useless joint unused035 with the delete key.

Now the other eye...... From the head_eyeball_left remove the joint unused033 with the delete key.

We have now a posable character..........

NOTE: If you use Maya 2012 skip the part 4 and 5.

PART 4. Labelling and renaming skeleton joints using the MotionBuilder naming scheme

Maya uses the same MotionBuilder's joints name and labels to build a working FK/IK system.

The picture below shows the joints we must rename and label.

This forums doesn't support tables tags, so I've done a downloadable table in PDF format. You can download from this link...........

In this conversion table you'll find the reference group number in the picture above, the joint name assigned in XNA, the label we must assign to it and the new joint name........ In this table some joint groups are missing because the corrisponding joints in the XNA skeleton simply doesn't exist.

Ok let's begin the work.........

We need to show all labels on our model's skeleton. The way we can see the labels is by going in the Skeleton menu, down to Joint Labelling and than we can go ahead to Show All Labels.

Now we can see the labels on our skeleton joints..........

Let's rotate the model to see it's back side. Now the left side of the model is the same with our physical left side. In this way we easily avoid mistakes in left/right label assignment.

Let's go to the Skeleton menu, down to Joint Labelling and to make this process easy let's go over the Add Joint Labels and press the MMB to detach the menu. Don't worry about it......... it will re-attach automatically to the menu system when we close the detached menu.

Place the detached menu where you want on the screen........

Now it's easy to select our joints and assign the proper label from the list in the detached menu.

Let's start from the skeleton root. Select from the Outliner the root_hips joint and the Label Root in the detached menu.

Now you can see the joint's label just over the belt has turned from the red none label into a green root label.

Now in the Attribute Editor we assign to the joint the new name. From the name conversion table you'll see that the new name to assign to root_hips joint is Hips.

Repeat the same procedure for the other joints.

We need to specify the left side and the right side of the skeleton. We can do very easily.

Select the top joint of the left leg.

Now click on the Left Label in the detached menu.

You can see that the labels color has changed to a blue color and a (L) mark appears in the label's name.

The Left label has been assigned to all the left leg joints automatically.

You have to repeat the same procedure for the right leg and both arms.

When the work is complete you should have a situation like this:

Ok. Let's move to the next chapter

PART 5. Build the full FK/IK system

To build the full FK/IK system we need to select the root joint of our skeleton's model from the Outliner.

Now let's go to the Skeleton menu, down to Full Body IK and click on the option square of the list's first item Add Full Body IK

A new window will pop-up.......

Be sure that the Identify joints active is By label and the Posture active is Biped, then press Apply

Now in the Outliner appears two new items: humanIK1 and fbikCharacter and the color of our skeleton now is purple.

Close the option window.

Maya has successfully built the FK/IK system for our model !!!!

Now we have to setup some other things. Expand the humanIK1 item in the Outliner

Let's hide these annoying labels. From the Skeleton menu, down to Joint Labelling and click on Hide All Labels

Now it's better

Select the LeftFootEff item from the Outliner. The Attribute Editor now is displaying the options we need to setup.

We need to make the effector's marker visible. From the dropdown menu Marker Look select the sphere and set the radius to 0.075. Now a little sphere appears.

Don't worry the sphere don't appear in your renders.

We need to do the same with the RightFootEff, LeftHandEff and RightHandEff. You can reduce the sphere's radius to .04 on both arms.

We need to unlock the arms effectors (it's the name of the FK/IK system manipulators). Select the LeftHandEff from the Outliner. From the dropdown menu Pinning in the Attribute Editor select unpinned.

Now select one of the effectors marker and translate where you want. I only moved down the left arm's sphere and nothing else. You can see the nice result

PART 6. Build the full FK/IK system in Maya 2012

With Maya 2012 Autodesk have removed the FK/IK system used from Maya 7 to Maya 2011. Now Maya 2012 shares with Motionbuilder 2012 a more powerful FK/IK system. You can notice the new tabs in the right margin of the screenshot..........

In the skeleton menu as you can see the submenu Full Body IK doesn't appear anymore. It's replaced with the new HumanIK submenu.

Open the new Characterization Tool. A new interface appears on the right.......

Rotate the model in the front view

We need to create a new characterization profile. Just click with the LBM on the star.........

In the bottom part of the UI we can read the confirm that the new profile has been created.

Be sure that the Mirror Matching is active. If it is not active just press with LBM the button as shown in the picture below

We begin to build our FK/IK from the Hip bone.

Select the Hip node from the [b]Characterization Tool[b]

Select the pelvis bone on the skeleton

Press the RMB on Hip node in the Characterization Tool and select Assign Selected Bone

Now Maya knows that the pelvis bone corrispond to the Hip node in the Characterization scheme. We know that because the color of the Hip node in the Characterization scheme has turned to green

Select the LeftUpLeg on the skeleton

Now select the LeftUpLeg node in the Characterization Tool

Press the RMB and select Assign Selected Bone

With the Mirror Matching active the node on the right side is selected automatically

Now select the LeftFoot bone on the skeleton

and select the LeftFoot node and press the RMB and select Assign Selected Bone

Now select the Hips bone on the skeleton

and the Spine node

Now we need to add more bones in the spine. To to this we enter in the Spine View simply clicking with LMB on the triangle as shown in the screen below

Now we are in the Spine View. Select the Spine bone on the skeleton

Select the Spine1 node and assign it to the bone selected.

Same thing with the Spine1 bone and the Spine2 node..........

Now we can go back in the Full Body View. Just click on the triangle as shown below

Now we enter in the Neck View

Select the Neck bone on the skeleton and the Neck node and assign to the bone as usual........

Back in the Full Body View.......

Select the Head bone and the Head node and assign to the bone

Now we enter into the Left Shoulder View

Select the LeftShoulder bone and the LeftShoulder node and assign to the bone

We can go back in the Full Body View

If we go into the Right Shoulder View we'll see that the Mirror Matching has selected for us the correct bone and node on the right side.

Ok. Back in the Full Body View

We'll select the LeftArm bone from the Outliner, the LeftArm node and assign to the bone

Due to the limitation to 100 images per post, the tutorial continues here :

Last edited by KTC; 17-02-12 at 16:45. Reason: Tutorial update
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