16 Replies Latest reply: Oct 23, 2014 8:25 AM by jolyonekanobi RSS

    Continuous Rasterization of vectors inside nested comps

    tomaugerdotcom Community Member

      Hi everyone, thanks for your responses to previous queries.

       

      I have a problem with vectors:

       

      I've got a bunch of comps that contain vectors animating. Inside the comps, the vectors are set to "continuously rasterize" which means that they come out nice and smooth no matter what the size.

       

      But I need to use these comps inside a larger composition, and I'm moving the whole comp around the screen with motion blur on it.

       

      But when the comp is set to "Collapse Transformations", motion blur is disabled. If I turn off "Collapse Transformations", it appears to over-ride the settings inside the comp, so none of the vectors are smooth. They all look like pixel-based images that have been scaled up. Horrible.

       

      I don't get it. I need those vectors to be crystal smooth, but I need the whole comp to have motion blur. How do I achieve this?

       

      This is a 2D question, I'm not using any 3D at all. I've read the relevant sections on Continuous Rasterization and on Collapsing Transforms and, as is the case with so much of this Adobe documentation that I'm being referred to, it does not address my specific case, though I can't imagine it's that uncommon.

       

      Thanks in advance!

       

      Tom

       

      PS: I can't denormalize the hierarchy because of the way the animation has to work - the animation itself is hierarchical, therefore the content must be structured in a smiliar hierarchy in order to work (think moons orbiting planets orbiting the sun)

        • 1. Re: Continuous Rasterization of vectors inside nested comps
          bogiesan-xSdJwH Community Member

          what happens if you use CC Force Motion Blur?

           

          bogiesan

          • 2. Re: Continuous Rasterization of vectors inside nested comps
            Rick Gerard CommunityMVP

            Make sure that you have motion blur enabled in the pre-comps. That should do it.

            • 3. Re: Continuous Rasterization of vectors inside nested comps
              bogiesan-xSdJwH Community Member

              Rick Gerard wrote:

               

              Make sure that you have motion blur enabled in the pre-comps. That should do it.

               

              I inferred this statement to mean he'd already tried that.

               

              >  But when the comp is set to "Collapse Transformations", motion blur is disabled. If I turn off "Collapse Transformations", it appears to over-ride the settings inside the comp, so none of the vectors are smooth. They all look like pixel-based images that have been scaled up. Horrible.

              >>

               

              Misread?

               

              bogiesan

              • 4. Re: Continuous Rasterization of vectors inside nested comps
                tomaugerdotcom Community Member

                Thanks to both of you for your responses!

                 

                @ Rick: thanks for reminding me to check my motion blur settings inside the comp. Unfortunately, this changes the rules about what items blur

                @ bogiesan: thanks for pointing CC Force blur to me, I wasn't aware of this effect. Unfortunately, this also changes the rules about what items blur

                 

                I'll need to provide you with a more concrete example so you can see why your suggestions may have different results than you anticipate:

                 

                Consider a screen capture that is zoomed in up close. The mouse cursor has not been captured in the original video: it is being re-animated using a nice smooth vector mouse cursor graphic. It needs to be continuously rasterized

                 

                As we watch the mouse move around the screen, there should be no motion blur on the mouse. Therefore, we must have motion blur turned OFF on the mouse cursor graphic, otherwise it blurs as the mouse whips around the screen.

                 

                However, now consider the entire screen is "whipped" off-screen. As it flies off screen, the entire scene blurs, including the mouse. It's no longer the mouse that is moving, but the entire screen is being moved, so the whole scene blurs.

                 

                If we have turned off motion blur on the mouse, and then collapsed our transformations, the screen blurs, but the mouse does not, even though it's moving away along with the scene. This looks highly unrealistic.

                 

                The CC Blur solution does the same thing, because it blurs ANYTHING that is moving within the composition, all the time.

                 

                When I go back to my original situation: where I didn't have motion blur turned on for the elements inside the comp, and I didn't have collapse transformations turned on for the entire comp, the motion blur worked as I described it: while the comp itself (the "screen") is not moving, nothing blurs - so the mouse doesn't blur as it moves around the screen; but then when the comp is animated in the main compositions' timeline, the entire comp is blurred (including the mouse). Unfortunately, all the vector elements inside the comp (the mouse, for example) are not re-reasterized, so they look horribly interpolated.

                 

                I understand that from a production perspective there are a ton of options, including taking static frames, or keyframing CC Blur on/off.

                 

                I think I'm trying to understand why "Continuous Rasterization" doesn't work inside a comp unless collapse transformations is turned on; and why once collapse transformations is turned on, motion blur no longer works?

                 

                thanks so much for your continued interest in this topic,

                 

                Tom

                • 5. Re: Continuous Rasterization of vectors inside nested comps
                  Tim Kurkoski Adobe Employee

                  In your given example, I think the most expedient answer will be for you to split your cursor layer in the pre-comp.  One layer for when you expect Motion Blur to be off, one layer for on which has the Motion Blur switch enabled.

                   

                  > I think I'm trying to understand why "Continuous Rasterization" doesn't  work inside a comp unless collapse transformations is turned on; and why  once collapse transformations is turned on, motion blur no longer  works?

                   

                  I assume you've read the description in After Effects Help about what the Collapse Transformation control does?

                   

                  Continuous Rasterization and Collapse Transformations do essentially the same thing but to different layer types, which is why they share a switch.  That thing is to tell After Effects to apply the transformations to the layer source before rasterization, instead of after.

                   

                  In the case of Collapse Transformations, the best way to think about it is that the layers of the pre-comp are elevated to the level of the parent comp.  Comp-level switches in the pre-comp are ignored, so if you were to have Motion Blur applied in the pre-comp it would turn off.  Comp-level switches in the parent comp are applied to the layers in the pre-comp.  So if you have Motion Blur on for the layer in the pre-comp, but not enabled for the pre-comp, you won't see it, same as if you had a layer in the parent comp that had Motion Blur turned on.

                   

                  That's a bit to wrap the brain around, so here's some practical examples, which you could create yourself if you want to follow along.  We'll assume a Pre-Comp containing a rotating Star shape layer, and this Pre-Comp is nested inside a Parent Comp.

                   

                  For:

                       Star layer: Motion Blur On

                       Pre-comp: Motion Blur comp switch On

                       Pre-comp layer in Parent comp: Collapse Transformations Off

                       Parent comp: Motion Blur Off

                  Resulting view of Parent comp: Star rotation is motion blurred.

                   

                  For:

                       Star layer: Motion Blur On

                       Pre-comp: Motion Blur comp switch Off

                       Pre-comp layer in Parent comp: Collapse Transformations Off

                       Parent comp: Motion Blur Off

                  Resulting view of Parent comp: Star rotation is NOT motion blurred.

                   

                  For:

                       Star layer: Motion Blur On

                       Pre-comp: Motion Blur comp switch On

                       Pre-comp layer in Parent comp:Collapse Transformations On

                       Parent comp: Motion Blur Off

                  Resulting view of Parent comp: Star rotation is NOT motion blurred.

                   

                  For:

                       Star layer: Motion Blur On

                       Pre-comp: Motion Blur comp switch Off

                       Pre-comp layer in Parent comp: Collapse Transformations On

                       Parent comp: Motion Blur On

                  Resulting view of Parent comp: Star rotation is motion blurred.

                   

                  For:

                       Star layer: Motion Blur On

                       Pre-comp: Motion Blur comp switch On

                       Pre-comp layer in Parent comp: Collapse Transformations On

                       Parent comp: Motion Blur On

                  Resulting view of Parent comp: Star rotation is motion blurred.

                   

                  Using the above examples, you can see that when Collapse Transformations is on for the Pre-comp layer, the state of the Pre-comp's Motion Blur switch does not matter.  All that matters is that the Parent comp has the Motion Blur switch enabled, and that the Star layer inside the pre-comp has Motion Blur enabled.

                   

                  Also note that we are completely ignoring the state of the Motion Blur switch for the Pre-comp layer inside the Parent comp.  This will only come into play if you apply a transformation to that layer, and is both disabled and ignored if Collapse Transformations is enabled for that layer.

                   

                  Clear as mud?

                  • 6. Re: Continuous Rasterization of vectors inside nested comps
                    tomaugerdotcom Community Member

                    Thanks, Tim, for this very detailed, and surprisingly clear (once I re-read it) explanation of Collapse Transformations.

                     

                    It still seems like a strange mechanic to implement, because there are implications here that aren't immediately obvious. For example,  enabling motion blur on a layer inside the pre-comp (that is static within the pre-comp, but animated in the parent composition), where the pre-comp is masked in the parent composition, doesn't have the desired effect when Collapse Transformations is used.

                     

                    The desired effect is for the masked shape to be blurred. That is, the element is treated as masked and then the whole of that element is blurred, making the edges of the mask blurry. The actual effect (which is logical, just undesirable generally) is that the element INSIDE the mask is blurred, but the edges of the mask are still sharp.

                     

                    To avoid this, you might be tempted to turn motion blur on for the pre-comp layer in the parent composition. Unfortunately then, animated elements within the pre-comp all are blurred whenever they move within the pre-comp. This may or may not be the desired effect (in my case it is not desirable).

                     

                    I agree that it appears the only workaround is to have a duplicate layer with alternate motion blur settings and to use opacity, possibly with a Hold interpolation to toggle between the two.

                     

                    Thanks for the advice and help thus far. Further input, ideas or contributions are definitely welcome!

                     

                    Tom

                    • 7. Re: Continuous Rasterization of vectors inside nested comps
                      tomaugerdotcom Community Member

                      A strange thing is occurring right now that I cannot understand. I have taken the pre-comp and cloned it (with CTRL+D). Both version have collapse transformations turned on. The layer with the original comp allows me to set or clear the motion blur switch; the new layer has a dash through the quality and motion blur switches and does not allow me to change the switch setting.

                       

                      How is this even possible, given that the second layer was cloned from the first? I no longer understand what the rules controlling the motion blur switch on a layer are, in the context of collapse transformations.

                       

                      Any insight will be appreciated.

                       

                      Tom

                      • 8. Re: Continuous Rasterization of vectors inside nested comps
                        Tim Kurkoski Adobe Employee

                        > How is this even possible, given that the second layer was cloned from the first?

                         

                        See the last paragraph of my previous response.  When Collapse Transformations is enabled for a pre-comp layer, the state of Motion Blur is irrelevant to the rendering order.  Thus the switch itself is disabled.  Remember that with CT off, the entire pre-comp layer is rendered before AE does anything else with it.  With CT on, it's the individual layers inside of that pre-comp that get rendered instead of the pre-comp as a whole, thus any comp-level switches are irrelevant.

                         

                        Initially, I think you misunderstood my suggestion. Your best bet would be to split the layer inside the pre-comp that you need to have multiple MB states.  Splitting the pre-comp layer doesn't help in this situation because it still sets the MB state at a level above where your problem is.  Your MB issue is at the layer level, not the comp level, so address it there.

                         

                        AE's rendering order is a complicated mechanism, yes.  Difficult to understand.  That's the nature of the beast, and also some of the inherent power of After Effects.  (One could argue here that node-based compositing would be more efficient.  For this given case they may be right.  But nodal compositing makes different tradeoffs than AE's nested layer-based model.  These are different tools for different jobs.)

                         

                        To better understand AE's rendering order and why it does what it does, I highly recommend Chris and Trish Meyers' Creating Motion Graphics books and blogs.  The books especially; they are the bible for AE's mechanical layout.

                         

                        Oh, and if I could make a little request- because this topic gets easily confusing, and the langauge to describe it difficult to accurately form, please post some screenshots or an example AEP for future questions.  Helpful both for me and for others. Graphic representations are always appreciated, and ease the pretzel-like transformation required to create a mental model from the words.

                        • 9. Re: Continuous Rasterization of vectors inside nested comps
                          tomaugerdotcom Community Member

                          Hi Tim, thanks again for continuing with the thread. I completely agree that a verbal description of a complex hierarchy combined with motion does not for easy parsing make! I will certainly attach screenshots, though video escapes me since you cannot directly upload video to these forums, and I'm uncertain how to attach a ZIP of the AEP.

                           

                          Just getting back to my latest observation - I'm not sure I understand how your previous explanation accounts for the behaviour I am observing in my timeline. I have two identical layers, each referencing the very same clip. One layer was created from the first (duplicated). The first layer gives me complete control over the Motion Blur and Quality switches for that layer. The second layer does not. Both layers have Collapse Transforms on. They are one on top of each other in the timeline, and I have not done any further editing since I duplicated the layer. And yet their behaviour does not match.

                           

                          Does this make sense to you?

                           

                          T

                          • 10. Re: Continuous Rasterization of vectors inside nested comps
                            Tim Kurkoski Adobe Employee

                            >Does this make sense to you?

                             

                            Er... No.  Now would be a good time for a screenshot.

                             

                            What's not clear to me is what types of layers these are (pre-comps, footage, solids) and the state of the switches (which gets more complex if they're pre-comps).

                            • 11. Re: Continuous Rasterization of vectors inside nested comps
                              bradmagnus MeganK

                              This isn't exactly the topic I was looking for, and I'm very late to the party, but for humanity's sake I'd like to add my input as I recently experienced the same sort of problem. My suggestion is to take the cursor out of the screenshot precomp, and animate it in the "main" composition. Of course that means you need to have the cursor parented to the artwork so that it'll mimic the movement, and when you want everything to blur, fake it with cc motion blur or a directional fast blur.

                              • 12. Re: Continuous Rasterization of vectors inside nested comps
                                tomaugerdotcom Community Member

                                Parenting is an excellent suggestion. At the time I wasn't aware that this was a possibility! Thanks for your comment!

                                • 13. Re: Continuous Rasterization of vectors inside nested comps
                                  uberxenith311

                                  I have figured out a way to achieve Constantly rasterize/Collapse Layers ON and have access to Quality and Motion Blur.

                                  Screen Shot 2014-03-26 at 5.28.21 PM.png

                                   

                                  Turn on the Constantly rasterize option and normaly it would put a dash in the quality and motion blur box. Now add a mask to the layer, in my case I didn't need a mask so I made a subtract mask outside the visible area of the comp. Once you have a mask the dashes will be removed and you can add quality settings and Motion Blur.

                                  • 14. Re: Continuous Rasterization of vectors inside nested comps
                                    ericsbowman Community Member

                                    Can't thank you enough for this suggestion. Works a treat. I had a large illustrator graphic in a precomp, with continuously rasterize turned on and all the motion blur settings enabled (for the comp and layer). It would not apply motion blur. I'm probably wrong, but this didn't seem to be an issue in CS6 for me. After adding a simple mask as you suggested, I was able to apply motion blur and maintain the great scalability of using continuously rasterize. Thanks!

                                    • 15. Re: Continuous Rasterization of vectors inside nested comps
                                      bogiesan Community Member

                                      Interesting workaround. Guessing here: Applying a mask forces the render pipeline to change.