Scaling a rigged character

I have been trying to scale up a pre-rigged item so that everything remains working. Such problems. So far the only thing that seems to work (almost) is to group mesh and rig, add an empty, and in the empty’s object properties activate duplicate Group and select the name of the group.

This gives me an instanced version that I can scale using the empty. However, the original is still there and actually I need to animate the original to animate the instanced version.

I suppose that could work but how do I get the original group to not render so I just see the scaled up copy in the final render.

And is there a better way to do this anyway?

Can’t you just scale the armature in object mode?

Yeah I’ve tried doing that, it all appears okay until I scale up the Armature and do any sort of animation, certain relationships in the rig stop working.
It’s not a rig I made so I don’t know for sure how it was set up, it has hydraulic sliding mechanisms that stop performing or change position.
Of course it doesn’t help that Blender is not my native app.

To hide the original group, you may be able to move the original or instance to a different layer.
This should prevent it from being rendered, just disable the layer while rendering.

The rig may already be setup on different layers, if so, disable the layers you want to hide during rendering.

There is also some rendering options in the Outliner for each object, Restrict Rendering.

Without seeing your rig - I offer the following comment:

I have done a lot of hydraulic cylinders and these normally have a bone with a stretch-to constraint to move the piston into the cylinder whilst rotating both as they should - you could try just resetting the length of this bone in the stretch-to constraint. If this doesn’t work can you just make a blend file with the armature in it and attach it here so we can dissect it?

Normal practice for a hydraulic cylinder is a stretch-to constrained bone, I call it Stroke, with a stretch-to
constraint to an actuating bone called “Crank” (maybe even an extended bone of the actuator whose length is irrelevant, so stretch-to works easily). You then have connected bones on each end of the stoke bone to control piston and cylinder. I have found that if I alter anything on this rig - like scaling, rotating or moving the individual bones, I have to reset the rest bone length in the stretch-to constraint to get it to work again. Hope this helps.

Here’s a blend file with a sample “simple” hydraulic cylinder rig - rotate, scale or grab the Crank bone to see it work - then mess about with the bones in edit mode and see you have to reset length before it works properly again. If this is not the problem, sorry to waste your time!

cylinder-problem.blend (471 KB)

BTW you can achieve the same results by using empties and constraints rather than an armature - scaling problems then instantly disappear! Just parent the whole assembly (mesh and driver empties) to a master empty and simply scale this to scale the whole mesh/rig.

Here’s the solution with the empties and armature, you can do all the scaling,rotating and grabbing of the master empty you like and it will still work:

Just noticed I uploaded the wrong file - this is the one I wanted (just press Play to see it operate) Sorry! :smiley:

cylinder-problem-ver2.blend (714 KB)

Use the master-empty to affect the whole rig and the crank empty to operate the mechanism, use rotate, grab or scale on the master empty or grab and rotate on the crank empty. :slight_smile: This rig based upon empties is my preferred method.

PS. I have snap-to-grid enabled in this project (the magnet icon), to override this hold CTRL while moving, etc.

Here’s something with hydraulic cylinders all over the place that have to move with the whole model and still work properly even when the rig is moving over the ground:


Wow, thanks for the breakdown. It was something that the animator had sent to me to try and fix, but he ended up working around the problem. But this is what would’ve worked so I’ll send him a link to this so he can get himself out of the bind next time it happens.

You’re welcome. You know I started with Blender just 7 months ago and I was told by a long term user that you cannot animate anything without Armatures. The most important thing I learn’t since then is that for mechanical components, like my mining models and clock mechanisms, etc. is the sad fact that armatures are generally bad news and should always be a second option - stick to Empties, Drivers and Constraints, these work much better, are more efficient and easier to control ONCE you have got your head around how they work and how to control them. I of course am quite prepared to be shot down in flames for this remark - it is personal opinion and I will fall with it, if it is wrong. Cheers Clock.

I decided to take this a little further and have developed my model a little. However a little problem has emerged! If you look at the model and find the two bright orange links between one set of crank empties and a couple of pistons, you will see the issue (change to front view and no shading). The movement of the pistons is defined by a Driver using the expression 2 * sin(var) for one and 2 * cos(var) for the other at 90 degrees, or in other words a sinusoidal oscillation based on a 2 unit radius. The empty driving this variable is a rotating motion, which must produce a sinusoidal oscillation as well. You might notice that the link lags behind the piston in one direction and and piston lags in the other. So my question “How can this be since both are sinusoidal motions based upon the same angle and radius?” I am confused. You will also notice that the empty tracking to the vertical pistons flips 180 degrees as the crank empty passes by the 12 & 6 o’clock positions - why is this? It seems that no combination of target and up axis, target z or space options change anything, yet the horizontal piston rig works properly. BTW hope you don’t mind me putting it here - should I start a fresh post with this issue or not?

Just press play to see it work.

Thanks

cylinder-problem-ver3.blend (1.4 MB)

PS. There are a couple of rigs for V6 engines (well the pistons and con-rods) in this file. The one using armatures works fine, the one using drivers has issues…