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Multi cameras switching ?

29 January 2016 17:22 #6936
Hi,I want to make a realtime cel-shading short film with multi cameras switching in the same scene (based on NLA),but the camera "marker" function in blender doesn't seems to work in B4W. And single camera may work in NLA by changing transform ,but that is too inconvenient。So how to switching cameras at the specific time ?
29 January 2016 18:11 #6937

So how to switching cameras at the specific time ?
B4w suports only one exported camera, so if you want to switch between cameras like in films, you need to bake all cameras movement into actions using blender animation baker, then convert all actions into NLA strip and combine from them long animation chain in timeline in one exportable camera. If you look into the sdk examples you can see there the Petigors_Tale game. If you push Intro button you can see a short movie made using this method.
Blend4web and that kind of thing.
30 January 2016 07:04 #6948

Ответ на сообщение пользователя Mikhail Luzyanin
B4w suports only one exported camera, so if you want to switch between cameras like in films, you need to bake all cameras movement into actions using blender animation baker, then convert all actions into NLA strip and combine from them long animation chain in timeline in one exportable camera. If you look into the sdk examples you can see there the Petigors_Tale game. If you push Intro button you can see a short movie made using this method.
Thanks! I'll try it . And I hope B4W support multi cameras exported one day. I once wanted to use UE4(with matinee)achieve the goal ,but the assets and animations exporting doesn't seems to be very compatible with blender.
30 January 2016 22:10 #6960
@cloudou A workflow that may work for you is:
Animate different empties to represent your camera views in Blender. Use Copy Transform constraints to attach your camera to the empties. Then you can keyframe the visibility (or influence sliders) of these constraints, and in doing so "hand-off" the camera between the empties.



Example setup: empty_handoff.blend

When you're done animating the empties and constraints (remember to Save As), you can bake the camera's movement.
Object > Animation > Bake Action
Remember to enable the Visual Keying option so that the effect of your constraints will be taken into account.





Example result: empty_handoff_baked.blend

The only drawback of a sudden camera hand-off is that if you are using motion blur it will blur between the huge leap the camera takes and look wrong. Currently B4W does not have motion blur, so don't worry about it. There is indication that motion blur is planned for the future, but by then support for multiple cameras may also be added. Anyway, this technique is something you can use for now.
31 January 2016 05:31 #6962

Ответ на сообщение пользователя Mentalist
@cloudou A workflow that may work for you is:
Animate different empties to represent your camera views in Blender. Use Copy Transform constraints to attach your camera to the empties. Then you can keyframe the visibility (or influence sliders) of these constraints, and in doing so "hand-off" the camera between the empties.



Example setup: empty_handoff.blend

When you're done animating the empties and constraints (remember to Save As), you can bake the camera's movement.
Object > Animation > Bake Action
Remember to enable the Visual Keying option so that the effect of your constraints will be taken into account.





Example result: empty_handoff_baked.blend

The only drawback of a sudden camera hand-off is that if you are using motion blur it will blur between the huge leap the camera takes and look wrong. Currently B4W does not have motion blur, so don't worry about it. There is indication that motion blur is planned for the future, but by then support for multiple cameras may also be added. Anyway, this technique is something you can use for now.
It's so kind of you.Thanks a lot!
31 January 2016 06:00 #6963
@cloudou You're welcome. Good luck!

Oh, and by the way, the "hand-off" technique works well when the empties are following Curve or Path objects too - like if you need the Camera to travel on a specific course.



follow_path_and_track_empty.blend
04 February 2016 09:37 #7109

Currently B4W does not have motion blur
I'm sorry! I gave you some incorrect info here.

Blend4Web does have motion blur!
You can see an example in the SDK. The path is: /blender/postprocessing/motion_blur.blend

I thought the feature had not been implemented yet, based on this statement: "This will allow us to then switch to higher quality rendering and also to add missing effects such as DOF, Motion Blur, Bloom and so on. "
Clearly, I did not interpret this statement correctly.

Whether the feature's implementation is considered complete or not, I do not know. But it's there, and it works.
 
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