In this tutorial I’m going to show you how to create tentacle like creatures using the Cinema4D hair system. You can assign polygon object to hair guides; this method is great because you can use different forces such as gravity and turbulence to create a realistic look. The hair/polygon objects also interact with each other as well as objects in your environment.
1. Create an object for the hairs to grow out of, in this case a disc. Change the amount of vertices in the attributes panel; I’m changing the rotation segments to 6 and keeping the disc segments at 4.
2. With the disc object selected, click on the hair menu at the top and then add hair. You should see you hair guides appear out of your object. At this point you can play around with the hairs tools to change and style the length of you hair guides. Make the guides longer and trim the outer guides and make the hair in the centre longer.
3. In the hairs tab of the attributes manager, fold out the roots title and change root from ‘auto’ to ‘as guides’.
4. We now need to create/find a polygon object to use as our tentacle. In this case I’m going to use a human arm and, specifically, I’m going to use Fred’s arm which is a free human model that comes with Cinema 4D. You can find it in the content browser/presets/humans/fred.
Click on Fred to load him into your scene, select the body element in the objects manager, then select point mode, and with the rectangle selection tool select and delete all the points so you are left with only his arm.
5. Click back on the hair object, then on the generate tab of the attributes manager where it says type, change if from ‘none’ to ‘instance’. Expand the instance title and drag the arm object into the object field.
There is now an instance of the arm object running along each hair guide although you probably can’t see them that well as they are so thin. To change that you will need to amend the thickness in the hair material by double clicking the texture in the materials manger. Then, click on thickness and change both the root and tip thickness to whatever suits, in this case 50. Make sure the value is the same in both to keep the right proportions.
Please note: if you find the arm is running the wrong way along the hairs then you will need to change the Y scale values of the arm object in the co-ordinates manager from 1 to -1. To do that, click on the size drop down and change to scale, then change the Y to -1.
6. If you click play now you will notice that some of the arms bend over and some stay upright. Now it’s time to start playing with some of the dynamics and forces settings to get the desired result and the look that you want.
Click on your hair object/forces tab and click hair to hair check box. Fold open the hair to hair title and change the radius and strength to whatever works. In this case, radius 50 and strength 10. Now click play. Change the gravity to anything between 0 and 5. This will make the arms settle in a more upright position.
You can also add random movements buy using turbulence. Go to the object menu/particle/turbulence to add it to your scene then click on your hair object/forces tab. Open the force objects title and drag the turbulence object into the forces box. Change the mode from exclude to include. Click on the turbulence object and change the strength, scale and frequency; 10, 100% and 20% respectively.
That’s it and good luck! Please post some links to your efforts in the comments.