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Master the Art of Limb Sculpting with M3DS Academy

🟠Learn about the anatomy of limbs for realistic sculpting.

🟠Understand the placement and interaction of muscle groups in the upper and lower limbs.

🟠Improve your sculpting skills with this detailed tutorial.

🟠Learn how to sculpt realistic hands and arms with proper muscle definition and proportional shaping in this tutorial.

1. Theory Arms and Legs

- Workflow

  • Before we get into sculpting we first need to look at how the muscles are placed on the arm to get a better understanding of how the muscles need to look.


  • Inside the same book, we showed off last class there are pages with illustrations showing how many muscles the arm has and how they will look when the arm is turned in a different direction.

  • The natural way how our arm is turned is when the forearm or palm faces toward the trunk.

  • The other direction our arm can twist is when the Forearm or palm faces towards the back or when it faces away from the trunk.


  • The Shoulder is made out of 3 parts, a back, middle and front part.

  • We can see from the illustration that the most noticeable muscles on the arm are connected to the shoulder such as the bicep and tricep muscle, even the chest muscle from the front.

  • The shoulder muscle ends at a point and we can see it go inside the Bicep.


  • The Bicep comes out from the front of the shoulder.

  • It is a cylindrical muscle that is a bottom-heavy muscle, this is because gravity is dragging the bottom muscle volume down.


  • The Tricep muscle comes from the back of the shoulder and separates into two parts.

  • There is some tissue that separates these parts in the middle.

  • Between the tricep and bicep, there is a smaller muscle

  • The forearm has a lot of muscles that are more noticeable when the arm is flexed.

  • We won’t be sculpting every individual small muscle but instead, draw them as one unit and define the split between those units.


  • The legs have a lot of different muscles, the most noticeable of these muscles is the one that splits the thigh with a diagonal line.

  • We drew this muscle even in the block out.

  • The muscles below have a tear-drop shape to them.

  • When sculpting these muscles it is important to define the lines where these muscles are.

  • You can see these same muscles clearly in this 3D Scan.

  • To look at things more in depth we’ll check out each of these muscles and how they wrap around the leg.

  • We need to not only pay attention to how they look from the front but also to how they look from the back and side.

  • This muscle wraps around the side of the leg and vanishes beneath the glute muscles.

  • The muscle facing the inside of the leg is smaller than the other two and can be seen right above the knee.

  • Moving onto the Calf muscle, it is located on the back of our leg and is split into 2 parts.

  • This split isn’t noticeable above the skin but the shape is still the same.

  • The shape of the Glutes depends on the gender you are working on.

  • Males have a more butterfly shape and an overall more block shape with a noticeable dent on the side where the going of the leg is connected to the hip bones.

  • While females have a rounder upside-down heart shape.

2. Sculptin Arms and Legs

- Workflow

  • We’re going to continue from where we’ve left off from the last Anatomy class and start by sculpting the shoulder.

  • Just like we mentioned previously the shoulder is split into 3 parts and has a nice point end.

  • You can adjust the arms of the model if they need to be using the Move brush.

  • Using the DamStandard brush we can draw out the parts of the shoulder muscle, we can also use our 3D reference to guide us through.

  • Once we split the muscle use ClayBuild up to add volume to the parts, smoothing them out with the Smooth brush and occasionally DynaMeshing.

  • Keep adding in clay and smoothing out the form.

  • If the shoulders are sticking out too much you can use the Move brush to move them into place.

  • Throughout this class, we will go back and forth between muscles to build them up slowly.

  • From the back, we’re going to draw out the Tricep using DamStandard.

  • The part of the Tricep facing the torso has a very strong “J” shape to it.

  • Start from almost the start of the shoulder muscle and make your way down the back of the arm, curving it toward the torso when you almost reach the elbow.

  • For the second part start from the curved part of the first line and make your way toward the front of the arm.

  • With ClayBuild up add in some volume on both parts and here is where the second part gets its unique shape.

  • It almost resembles that of a chicken wing.

  • Keep adding in clay and smoothing it out.

  • Don’t forget to strongly define the lines that separate the Tricep into two parts.

  • We mentioned that in the middle of these parts is where some skin tissue is located.

  • Using ClayBuild up start adding clay around that area.

  • Start from the bottom middle of where the two lines separate.

  • Add clay on the top part of the Tricep to blend it in nicely with the shoulder.

  • For the shoulder, we can define the line separating it from the Tricep more and add a bit more clay using ClayBuild up.

  • Moving onto the Bicep we first want to draw out the small muscle between the bicep and tricep.

  • With DamStandard start from the pointy end of the shoulder and make your way down, curving it at the end when you reach the end of the tricep muscle.

  • From the side draw out a line next to the curve that goes up next to the tricep.

  • After that add in some clay using ClayBuild up and the Clay brush.

  • Now that we have the middle muscle drawn out we can start working on the Bicep.

  • Starting from the inside of the armpit draw out a line that reached down to the beginning of the forearm and from the other side draw the second line to make the form of the bicep.

  • With ClayBuild up add in clay on the bicep, DynaMeshing occasionally and smoothing out the clay using the Smooth brush.

  • There will be a lot of back and forth between each muscle, we’ll also be going back to other parts that we’ve done in the previous class to refine the shapes.

  • With DamStandard outline the back muscles a bit before moving onto the forearm.

  • For the forearm draw out a line going from the end of the bicep towards the wrist.

  • Add in clay using ClayBuild up.

  • On the other side of the line add in clay making sure you also add some volume on the side and back of the arm where the muscle wraps around.

  • We can take this opportunity to sculpt out the elbow itself, connecting it with the skin tissue where the Tricep is split.

  • From the back of the forearm make a line starting from the elbow, going down the forearm at a curve.

  • With ClayBuild up add in some muscle volume.

  • With the same brush make a hole on the side of the elbow, adding in small amounts of clay around the hole, soothing and DynaMeshing it.

  • If the hole is too noticeable, add some more clay on top and smooth it out again.

  • This hole shouldn’t be that noticeable in our model but visible enough to the eye.

  • On the side of the arm use DamStandard to make a line going from the side of the elbow down to the wrist.

  • Just like always add in clay with ClayBuild up after you draw out the line.

  • From the back of the arm again, make two lines going down the forearm from the elbow down to the wrist at a curve, adding in clay afterward.

  • From the side, we’re going to refine the muscles we made previously by adding more clay to the muscle and drawing out the lines with DamStandard if they start fading out because of smoothing and DynaMesh.

  • Going back to the elbow, refine it by making the rest of the shape and use the Flatten brush to give it a more flat surface.

  • We can see from our 3D reference that the thumb has a muscle that connects it with the forearm.

  • Using ClayBuild up add in clay and smooth it out.

  • Make a hole on the side of the muscle, smoothing it out and DynaMeshing.

  • If the muscle is too small you can use the Inflate brush to make the muscle stick out more.

  • Going back to the elbow we’ll make the indents on the side with DamStandard and define the skin tissue in the middle of the Tricep.

  • Moving to the legs we’ll start off by drawing out the big diagonal line going from the start of the hips all the way down to the inside of the thigh.

  • After drawing out the line add in clay on the inside and outside.

  • Using the Transparent mode draw out the three muscles on the thigh using DamStandard.

  • After drawing them out add clay to each of them using ClayBuild up.

  • Don’t forget that some of these muscles wrap around the side of the leg, going all the way back to the glutes.

  • If the muscles turn out too bulky you can always use the move brush to make them smaller by squishing them down.

  • Once you are done adding in the clay to form the muscles smooth them out and DynaMesh the model.

  • Use the DamStandard brush to define the muscles more by drawing them out again.

  • We can use this opportunity to add more clay on the inside of the thigh near the crotch, as well as draw out the lines on the hips that separate the torso and legs.

  • After we are done with the thighs we can move on to the knees.

  • Add in a nice amount of clay in the middle then add in clay on the sides.

  • Still using ClayBuild up make wholes on the side and bottom of the knee, resembling that of a face.

  • Add in more clay around the holes before DynaMeshing and smoothing it out.

  • With DamStandard make two indents on the side of the knee where our “eyes” were on the face.

  • We’re going to add more clay in the same places we did like in the beginning, adding more in the middle this time.

  • Make sure the knee doesn’t stick out too much from the side.

  • Add in clay on the top of the knee where the muscles are to make a nice transition between them and the knee.

  • After that DynaMehs the model and smooth out the knee.

  • With the Flatten, brush make the top and bottom of the knee flatter to give it more of a hard surface.

  • Using ClayBuild make the bone of the leg that goes down the knee.

  • DynaMesh and Smooth it afterward.

  • On the back of our model, we’ll finish off the rest of the leg muscles.

  • Using ClayBuild up we’ll start off by making the Calf muscles.

  • You can use the reference as a guide to help you make the shape.

  • With DamStandard refine the two lines on the Calfs before DynaMeshing and smoothing them out.

  • For the back of the thighs, use the reference as a guide and draw out the rest of the muscles using DamStandard and fill them in with ClayBuild up.

  • Make sure you make the muscles correctly from each side, adding and smoothing out clay as you go.

  • Behind the knee draw out a diamond shape, using ClayBuild up to make a small hole inside of it.

  • With the same brush add in clay inside but not fully filling in the shape, only focusing on the middle.

  • With DamStandard make two indents on the side of the added clay.

  • Add more clay outside of the shape to make a nice blend with the rest of the muscles surrounding the back of the knee.

  • Lastly, we’re ending this class by sculpting out the glutes.

  • Add in clay and make a shape of a butterfly, on the sides use DamStandard to make the indents next to the glutes.

  • Refine the shape some more if needed.

  • End Result.

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