Taking a step back - Foot slides

Hello all! I have decided to scrap the chasing tail animation now as to be honest, I really messed up the workflow of the overall project and it has proven itself to be too challenging. I have naively thought that this would be a simple task to do however, it just shows how little knowledge I have when it comes to quadruped rigs. Further more this has made me realise that I am still a beginner in this area as an animator.

So, my next question which I put myself in is, “what should I animate then?”. I had a lot of ideas running through my head the past few days and i’ve tried to keep them as simple as I can so that, I’m able to have include a shot that has a certain quality in my showreel. I was then watching a walk cycle tutorial that I had mentioned from a previous post about how to animate a quadruped walk cycle. As I continued watching, it struck my mind that I have yet to resolve a certain issue that I have yet to conquer, “foot sliding” in a cycle animation. 

I'd often at times searched the web on how to resolve this, but from what I had seen there wasn't much content on this issue, sure there was mel scripts which i could use, but I wanted to know the reason and find that formula on how to fix this.

I knew that this tutorial had mentioned how to resolve the problem but at the time, I was concerned that I would copy what this person has done and never learn how to animate myself; therefore I chose not to, take on board the tips he had suggested at the time. How foolish of me.

Anyway, I believe that I’m able to prevent any foot slides when it comes to making a cycle animation now, thanks to this tutorial. Feel silly not having mentioned this person name yet, but I’ll include this tutorial on the following link below, as he has really opened new doors in term of animation projects in the future for me. Plus, in case I might lose you guys with my wording on how to prevent the foot slides. Chris Sokalofsky - Basic quadruped cycle tutorial

Alright, so I have set a simple scene up, with a spider bot rig, nothing fancy as this is just to illustrate the steps to take to prevent foot sliding in Maya, with your animation. I've only just figured this out so please bear with me if this whole tutorial fail.

So below, I have animated the front left leg where it starts at frame "0" and moves forward at frame "8" , where by frame "16", it'll go back to it's original position on frame "0". At the moment from the graph editor, the splines are flatted out. We would then need to change this.

Translate Z - Front Left foot 

 I then had to identify which area of the spline we would need to turn "linear" as this will make the foot move forward at a constant speed, with no curve to influence the timing. So below, I have then highlighted frame 8 and 16 keys and turned them linear.

Translate Z - Change flat to Linear

 With that done, I then highlighted all of my key frames from the translate Z and from the graph editor select, curves, pre- infinity, cycle. I then did this again but selected "post infinity", cycle. This would then allow the animation to cycle continually for "X" amount of frames. (Note, that I would bake this, but that's another subject for next time). I would then copy and paste all of this to the other legs for this rig, make sure you do this.

Checking infinity 

Afterwards, I then highlighted the linear curve from the feet and then copy and paste this to the global/ world curve on the Z axis.

Copy the linear curve

 Now the tricky part in my opinion. Depending on the linear curve, and the direction you have been animating your rig, you may need to mirror the curve (scale the curve to -1). So, for example from 0 to 8, at frame "8" the translate Z is "-87". But we don't want this as the rig is going the other way now. We simply add a positive from that negative, "-87=+87", this is scaling to "-1". The rig should then move in the correct direction. Make sure that the curve is travelling in linear mode. To do this highlight the key frames, select curves, post infinity, linear.

Paste onto the world/ global curve

I would like to mention that you should research before animating and this is just a tutorial on how to prevent foot slides. Pay close attention to detail on your foot placements and the principles. I have not mentioned any but be aware of them.

After learning and taking all of this in, I have grown a new confidence with what I should animate over the next couple of weeks. So again, I apologise with the lack of content I have been churning out lately. I hope however, that you've found this useful.