How to rig a drawer? I'm a noob to DS rigging and can't figure it out...

Inkubo

I have a vanity table with a drawer. The vanity and its drawer belong to separate "vertex groups" in Blender, so when I import the object into the Figure Setup tab, I get two bones; one for the vanity, one for its drawer. I drag the Drawer bone to become a child of the Vanity bone.

Then I create the figure. It appears in my scene, and after making sure it is selected in the Scene tab, I switch to the Node Weight Map editor, right-click in the Viewport's empty space, and choose Weight Editing > Fill by Bone Selection Group(s). I think this serves to make sure all vertices in the Vanity group are weighted 100% to respond to the Vanity bone, and all vertices in the Drawer group are 100% weighted to respond to the Drawer bone.

Then I rig the figure so the Vanity bone sticks straight up from 0,0,0 to where the drawer is, and the drawer's bone begins at the end of the Vanity bone and sticks out horizontally in the direction the drawer opens. After memorizing the rigging, I try the sliders for the drawer. It will twist and rotate in all kinds of inappropriate ways, but there is no way to extend it. No matter how I orient the bone, I can't find any position that will make the drawer slide smoothly in the desired direction.

I tried one more thing that I thought would be crazy: I recreated the figure, but this time without a hierarchy. The Vanity bone and Drawer bones aren't parent and child, but siblings. I thought maybe this would bring back the Translation sliders that get hidden for child bones. When I rig this up, the sliders do indeed appear when the Drawer bone is selected, but adjusting them moves the drawer's bounding box around without dragging any geometry--as if weight mapping didn't work.

What is the proper way to rig a drawer so the user will have a convenient Parameter slider to open and close it?

andya_b341b7c5f5

First, I think you're right that the drawer bone shouldn't be a child of the vanity bone.  You say the drawer (mesh) doesn't move when you move the drawer bone 'as if weight mapping didn't work'.  You may be right.  What does the weight map for the drawer bone actually look like?  It should be 100% influence for the drawer bone on all the drawer mesh and no influence on the drawer mesh for the vanity bone, of course.  If it isn't, you can manually weight map it to be that way.  Then lock the axes on the drawer bone that you don't want to move.  I am assuming the drawer bone is aligned with the drawer from front to back (or back to front, won't matter).

Second, I wonder if it wouldn't be easier just to make a morph to slide the drawer out?

felis

If you show hidden, you should get translations in parameters which can move an object, like an drawer.

Inkubo

andya_b341b7c5f5 said:

First, I think you're right that the drawer bone shouldn't be a child of the vanity bone.  You say the drawer (mesh) doesn't move when you move the drawer bone 'as if weight mapping didn't work'.  You may be right.  What does the weight map for the drawer bone actually look like?  It should be 100% influence for the drawer bone on all the drawer mesh and no influence on the drawer mesh for the vanity bone, of course.  If it isn't, you can manually weight map it to be that way.  Then lock the axes on the drawer bone that you don't want to move.  I am assuming the drawer bone is aligned with the drawer from front to back (or back to front, won't matter).

Second, I wonder if it wouldn't be easier just to make a morph to slide the drawer out?

The bone was indeed aligned from back to front of the drawer. I found that when I aligned it from side to side on the drawer and unhid the Translation controls (thanks @felis!), I could use the Y-axis slider to move the drawer. But it worked strangely, like nothing I've seen in DS: whenever I began to move the slider, the drawer's geometry immediately snapped to its starting (closed) position. As I dragged the slider, I could see the drawer's bounding box move, but the drawer itself remained closed; then when I let go of my left mouse button to "drop" the slider, the drawer's geometry snapped to where the bounding box ended up. The drawer didn't slide out smoothly like you'd expect, it just jumped from the closed position to wherever it should be when I dropped the slider.

However, I went ahead and saved it as a prop, then cleared the scene and double-clicked on the newly created icon to load it. When it came back in, now the slider worked well and the drawer animated smoothly as it opened and closed. Very weird. But, thanks to help from both of you, I now have my first rigged prop!

3WC

It always does that, I think it's a bug. Saving and reopening fixes it, as you found out.