# HM-3670: Position a Dummy Using Limiting Constraints

In this tutorial, you will learn how to position the H-point of the dummy on a seat cushion.

This helps to reduce design and remeshing of the seat based on the pre-stress analysis. To do this exercise you will be using a limiting constraint and freehand morphing.

This exercise uses the dummy.hm file, which can be found in the hm.zip file. Copy the file(s) from this directory to your working directory.

## Open the Model File

In this step, you will open the model file, dummy.hm.

1. Open the model file, dummy.hm.
2. Review the model.

## Create Constraints

In this step, you will create constraints.

1. From the menu bar, select Morphing > Create > Morph Constraints.
2. Set name= to const1.
3. Set type of constraint to on elements.
4. Set the option under nodes to bounded.
5. Set project along: to N1,N2 along negative z (choose from side of cushion).
6. Set distance= to 2. This will ensure that there is a distance of units between the dummy and the seat after the morphing is complete.
7. Use nodes >> by collector and select cushion.
8. Click select.
9. Use elems >> by collector and select dummy.
10. Click select.
11. Click create.
Constraints with a diamond shape are created.

## Morph the Part

In this step, you will morph the part.

1. Right-click MorphingConstraint in the Model Browser and select Hide.
2. From the menu bar, select Morphing > Free Hands and select the move nodes subpanel.
3. Switch the moving method to translate.
4. For moving nodes, use nodes >> by collector and select cushion.
5. Click select.
6. For fixed nodes, use nodes >> by collector and select dummy.
7. Click select.
8. For affected elements, use elems >> by collector and select cushion.
9. Click select.
10. For the translate magnitude, set the following:
• X = 0
• Y = 0
• Z = 80
11. Click morph.
The top surface of the cushion has conformed to the shape of the dummy. The distance between the dummy and the seat-cushion is 2 mm. Using limiting constraints, you are able to move a mesh such that it moves an adjoining mesh along with it, thus preventing penetration between the two of them.