3 Replies Latest reply on Jun 18, 2012 9:36 PM by Dave Merchant

    Animated 3D model based on external data


      Hi all,


      I'm a structural engineering master student currently working on a seismic evaluation of a temple structure in Portugal. For the evaluation, I have created a 3D block model of the structure and will use a discrete element code to analyze the behaviour of the structure under a variety of seismic (earthquake) records. The software that I will use for the analysis has the ability to produce snapshots of the structure at regular intervals which can then be put together to make a movie of the response. However, producing the images slows down the analysis. Furthermore, since the pictures are 2D images from a specified angle, there is no possibility to rotate and view the response from other angles without re-running the model (a process that would take 3 days of computer time).


      I am now looking for an alternative method for creating a movie of the response of the structure. What I want is a very lightweight solution, where I can just bring in the block model which I have and then produce the animation by feeding in the location and the three principal axis of each block at regular intervals to produce the animation on the fly. I'm creating the model using Rhino + Grasshopper and so I can easily import it into Acrobat as 3D objects. The model is composed of about 180 blocks with 24 vertices per block (so 4320 vertices). The location and three unit vectors describing the block axis are produced by the analysis code and I can write them out in a way that I want.


      The main issue is that the quality of the animation should be decent. If the system is vector based and allows for scaling, that would be great. I would like to be able to rotate the model in real time with simple mouse dragging without too much lag or other issues.


      I think it is possible to use Javascript to manipulate the 3D meshes in PDF. I have used Javascript before and I will make the effort to learn how to use it with Acrobat. However, I am not sure if this will be very difficult to manage and will in the end work properly. That is why I wanted to ask the experts here so that I don't waste my time on something that will not work in the end.


      I would be very thankful if some of the more experienced users could share their insight about this project and point me in the right direction. I am not sure if this is appropriate, but if you feel that there is another program or approach that is more appropriate for this task, I would love to hear about that as well.




        • 1. Re: Animated 3D model based on external data
          Dave Merchant MVP & Adobe Community Professional

          You cannot animate 3D meshes within Acrobat at the vertex level, so "morphs" of shapes are not possible. Animation support is limited to object-level functions such as position and rotation, and material properties such as color and opacity.

          • 2. Re: Animated 3D model based on external data
            cannibal_flea Level 1

            Okay. But each mesh is an object in the file, right? Since the blocks are rigid, all I need is to change position and rotation of each block. I won't need to modify vertices since no deformation at the mesh level occurs. Is that possible?


            If this is a possibility, then the next question is: can it be done for 160 blocks for 36,000 steps (36 second run with data at 0.001 seconds)? how is the performance?

            • 3. Re: Animated 3D model based on external data
              Dave Merchant MVP & Adobe Community Professional

              Yes you can move objects in 3D space (either using scripts or animations embedded within the U3D data) but performance is nowhere near that good - Acrobat's 3D engine is not intended to provide game-level performance so on a typical desktop machine you'll only get a handful of steps per second.


              Since the human eye can't distinguish more than 20-30 frames per second there is no reason to go beyond that, and in an interactive 3D scene 5-10fps is fluid enough for most people.