Floating objects

I’m using a plane mesh which has a displacement texture applied to it, which is in turn mapped to an empty, which creates random waves when rendered (based on Cog’s seascape turorial at http://www.cogfilms.com/tutorials.html).

Is there any simple way to get objects to float on these waves? I’ve tried applying a similar texture deformation to the mesh I’m trying to float, but it not only deforms the location of the mesh but its shape too. Anyone got any ideas?


Try parenting your object to the empty ?


You could experiment with collision detection to get the effect you want

Parent your object to the vertex.

Vertex parenting is the way to go. However you have to use 2.43, as in previous versions the displacement texture only works on the render and doesn’t really move the vertices. Here is how you do it in 2.43 with the new displacement modifier. I haven’t done Cog’s tutorial in ages but the first steps should be the same.

Create the plane, the empty, and the animated texture as Cog describes but don’t map it to the empty. Also turn off all the mappings in the Map To panel.

Select the ocean plane in object mode, then F9->Add Modifer->Displace. In the Texture: field enter the name of the wave texture. Open the lowermost menu of the modifier panel and select Object. In the Ob: field that appears type the name of the Empty.

Your texture should be displacing the ocean now in the 3d window! Move the Empty around to see the effect. THese are two great benefits of having displace as a modifier rather than a rendered texture.

Select your floating object. Shift-select the ocean. Tab into edit mode. Select exactly 3 vertices under your floating object. Ctrl-P, create vertex parent. Try animating the wave texture now and your object should bob on the waves.

Ohhhhhh… True, I forgot that it only works properly in 2.43. <:] I’m too used to the new features, I guess.

I downloaded 2.43 and used the displacement modifier - it works well! thanks for the suggestion.

The only thing is, the object follows the wave movement so exactly that it flicks about a lot, which is a bit unrealistic. Is there some way of increasing the weight or something so that the movement is delayed, or toned down, a bit?

Try turning on Slow Parent for the boat (F7->Anim Settings->Slow Parent). Experiment with different offset values in the Time Offset box at the bottom of same panel. It can also help smooth motion if the 3 parent vertices are more widely separated (they don’t have to be connected).

Yeah, experimenting with those has pretty much got it perfect. I’ve kept the vertices pretty close as I found if I spread them about the movement didn’t really follow the waves close enough… but those other settings have sorted it out. The wonders of 2.43…

Thanks for your help guys.