Hello, i’m trying to render a single shot of a space filled with people, I would like to have a motion blur effect to simulate the movement of those.
Is there any chance to have this effect just with native Rhino and Vray?
No, only Maxwell supported object motion blur some years before.
You can create this effect pretty easy in 3ds max. Otherwise I would recommend a rendermask including all the people and then use photoshops motion blur to create the effect.
My eyes 
yes, how did you do that?
V-Ray supports both camera and object motion blur. You just need velocity vectors. Here I made a small 2 frame animation, where I rendered the second one. V-Ray takes velocities from the differentiation between the frames, and that’s it
Totally noob with gh but I totally understand the process. Are the object or the camera moving here? Could you share the gh file by any chance?
Thanks !
Is there a way to add vectors to objects? Best rotation and translation.
This is Camera motion blur here. I just moved the camera a bit i frame 2. for objects, velocities are inferred from the differences of the positions of the objects between the frames.
V-Ray for Rhino sets 1 frame per second, so every new frame advances the time by 1 second. Thus having positions and time V-Ray infers the velocity using simple linear equation (the one from 4th grade in school)
basically that’s it.
Is it possible to move the objects rather than the camera to obtain the same effect?
yes, but it is a bit more complex. You must be using V-Ray for Grasshopper for the object animation, but render the whole thing 8n Rhino, since no motion blur in VfGH
Also you may set the whole thing 8n GH and export a vrscene file. Then edit the file to manually enable the moblur.
it is a matter of preference.
Hi Nikolay, with motion blur how would Rhino get the motion vector from grasshopper, based on the example you wrote here? Also tested enabling motion blur in the vrscene, but not much luck.
V-Ray captures the entire camera animation from GH when you use the RenderInProject component in GH. Then you will see the captured animation in the AssetEditor’s animation tab
here is a simple setup:
You click on that menu, and then the component will run the animation (e.g. prepass) to capture the transformation. Afterwards you go to the AE and select “Grasshopper” for the source:
Alternatively you can export a .vrscene from the GH definition and manually change the mblur parameters, then you can render with V-Ray standalone/Cloud, depending on your needs
demo files attached
simple_path.3dm (95.0 KB)
simple_path.gh (12.5 KB)
There used to be a courseware on that somewhere, but I can’t find it
edit: found it: YouTube
thank you Nikolay, for the fast reply. I understand the camera animation can get Rhino Motion Blur, but i thought reading your post above that it was possible to enable object motion blur without any camera movements.
Right.. misunderstood the intent.
I read only 5 posts above, but should have read 10 
So, let me clear couple of things first:
- V-Ray for GH can only export Sun and Camera animations to V-Ray for Rhino.
- GH animations are actually stills. The GH solver engine is invoked to calculate the definition for each frame and then V-Ray renders it. The whole thing is basically a batch render
- You can really animate objects in Rhino only using Bongo. In the current version V-Ray does not read the animation as “animation” but as stills. Yet again - Bongo is basically a batch scene emitter, with a solver in between each frame. There will be some changes to this in V-Ray 7.1
That being said, you cannot have truly animated objects in Rhino. The only way to make V-Ray render motion blur is to cheat Rhino a bit (or a lot).
Currently your options are:
-
Have an animated .vrmesh or .vrscene proxy, generated in GH. Import that in Rhino. and then make a camera path animation, where the “path” is just a point, and the length is the length of the GH animation the proxy was exported with. The latter will activate the Animation rollout in the AE where you can enable the (object) motion blur
here you can see that works
the proxy is produced from this GH definition:
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You wait for V-Ray 7.1 and check whether the bongo support enhancements would work for you.
Attaching all the files here:
object_path.zip (41.0 KB)
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could we drive animation offset of a vrmesh from grasshopper or python ? just as a preview
If I understand correctly you want the animation to render every n-th frame ?
This is possible in V-Ray, but not in GH. The timeline component is always advancing 1 frame per step.
We got this question before once or twice, if that is a useful feature, I could be implemented relatively easy
im refering to the VR mesh Animation Offset ,that exist in AE(which can be used in interactive rendering mode to see the Vr mesh animation movement allowing me to see motion blur). Though in grasshopper the vrmesh doesnt have the option offsetting…if its possible to drive the offsetting through a slider or access the animation offset from python.