Stress Test

Stress Test

This is a truly stressful task and very time consuming so this post will start with a recommendation, anyone who is even thinking about doing a stress test some recommendations would be, do a lot of research about it first for example there is a YouTube channel called 3ds max learning channel which teaches a great deal about this subject and element of character studio. Another recommendation would be if there is a deadline to stick to make sure this part or milestone of the project has a great deal of time allocated to it because this process can take weeks to perfect. The last recommendation is when everything is going wrong try and get a peer or a friend to watch over while creating the rig because it adds an extra level of concentration if the stress test goes wrong the first couple of times.

This has been the biggest struggle of this part of the project and its because it has been underestimated and for this the price has had to be paid dearly for this mistake. The stress test has set the project back because of time issues the animation which was intended to be created now cant be because of the amount of time spent trying to get the stress test right. Instead if my final idea being the animation a sort of snippet or trailer would have to be created in its place.

So once the rig has been built its time to begin the stress test which isn’t difficult but more fiddly. This is why the bones created in the rig are very important they match the mesh for first timers. The stress test can be completed in many different ways and it can be done either manually or automatically, the reason for the stress test is to make sure that the bones created in the rig are attached to the correct part of the mesh, as simple as this sounds it’s a very difficult task if the rig has not been created properly.

To start the stress test the mesh needs to be attached to the rig, this can be done from the modifier list and by selecting “Skin”. Once this has done the user has to simply select add in the options list in the skin modifier and a list of bones will appear created from the rig. It took a while to get it right for this project and will be explained later in the post but for now all the bones need to be selected by pressing “All” and then selecting “Select”. This will add all the bones created from the rig and put them in order from head to toe for the user. Once this is done if “Editable Poly” is underneath “Skin” underneath the modifier when the mesh is selected the user should make sure no editable element is selected for example Poly select, this is because the rig will still think the user is editing and therefor will not attach to the mesh.

Next step that is the stress test itself is to select one of the bones in of the mesh and select the “Motion” tab; this will open up a motion panel for the CAT Parent. There is an option about mid range of the motion panel which has ABS written in green writing, this would allow the user to add an Absolute layer to the rig which will allow the user to do a manual stress test. For the purpose of time this project will go through how to do the stress test automatically because doing it manually will take time and will require the user to animate movements frame by frame.

So if the user selects the “ABS” Button and holds it down further options will appear, these options will allow the user to do further editing but the one used for this project is the last one which looks like a small man running. If the user selects this nothing will happen to the mesh yet. The next part and is the moment of truth is to select the stop button above the layers display and press play. This will show if the bones match with the mesh because the bones will move and since they have been linked with the skin they will try and move with the skin.

If this is the users first time doing this test then it will most definitely not look correct and parts of the body will be left behind and it will just look very very bad. This is not a problem and can be fixed but just incase the bones like explode in size and everything becomes distorted which happened a couple of time during stress test for this project the best way and is recommended is to just close 3ds max and re open it and make a new rig. If its not exploded and everything looks the same size as you made then you are ok.

The next step and the way to fix the distortion problem would be press the stop button and re select the mesh and go back to the “Skin” modifier. Once the skin modifier is open select the “Edit Envelopes” button in the options underneath. The bones will disappear and black lines will be replaced, this are basically the envelopes in which link the mesh to the bone and has a sort of heat sensor look to them once they are selected. This is now the fiddly part because the user must now move, expand and retract these lines so that the right part of the mesh is connected to the right part of the bone. One recommendation at this point is that the red areas highlighted on the mesh show that that part of the body is linked 100% to that bone, blue mead that another bone is occupying that particular part of the mesh and orange or yellow means that only part of that mesh is connected to that particular bone which is selected. 

At this point the research conducted should help the user understand what they need to do to make each bone match the mesh and they will need to go back and forth to the motion panel to make sure whatever they have edited actually works and has not made the mesh look worse when moving. Another recommendations would be to edit one area at a time and keep testing especially with the orange areas because the user needs to make sure that the other bone that also occupies that space has covered enough of the mesh to for example lift the whole leg instead of leaving half of it still on the ground.

This will take a long time and is a very stressful process and for this project a lot of tutorials and recommendations have been taken on board which got to the stage where the mesh and rig have been linked together nicely with only a slight distortion but it had to be accepted because this process has taken weeks to get to just this particular point and time was running out.

Another thing which the user may find which was mentioned earlier in this post was that the mesh may begin to drag a lot and during this project the troubleshoot of it was only learned towards the end which was very frustrating. Basically when the rig was first created it started with the pelvis but if this was renamed for example to “Hero_ “ every bone will be named similarly. If the user takes a closer look at the bone list they may see that the first bone in the list is probably named in the same way and has a bone towards the feet. This turns out to be wrong and its actually linking the feet to the CAT Parent. It simply needs to be removed so that the head is the first bone on the list and this will stop the drag. Any further dragging occurring after this bone has been removed would need to be adjusted in the Envelopes option.

Another way to get precise links between the mesh and the envelopes would be to select the vert’s option and stat linking individual vert’s of the mesh to the bones, this this can be achieved by selecting the vert’s which are being left behind one body part at a time. For example if one vert is not connected to a bone and is stretched on the left hand middle finger, the user simply needs to highlight the vert and if the user scrolls further down the “Skin” modifier there is a button with a small spanner. If the user selects this a list of bones will come up at the bottom and the user needs to simple select the bone they want to link that particular bone to and select the button “1”. This basically means that the vert will be linked 100% percent to that particular bone which was selected, there is a big catch to this because if the wrong bone is selected the vert may move to another position so some experimentation needs to be done. This method is probably the best once the user has done all they can with the envelopes and only needs to make minor adjustments.

This is basically the stress test and it has taught many lessons for this project and cost the project a lot of time and effort but was partly achieved towards the end. there are some images below showing the hero of this project going through the stress test but because it was such a time consuming task more concentration was used on getting it done rather that taking reference images. but once the stress test was completed on one of the models it was easier to load the previous rig and make some minor adjustments to the bones because the characters are very similar for this project.