I´m about to render, tips on cutting down the time?


I´ve used Blender on and off for about a year and at the moment I´m helping out some colleagues presenting a solution on how to change an electrical switch to a safer type.
They want the animation around the end of the month, so thats about 12 days.
There´s 2749 frames to be rendered, so I could really need some tips on how to cut down render time.
I´ve gathered points at Sheep-It for a month now, so I guess I´ll have most frames rendered there, and I have 3 computers working at home, each with about a GTX 760 performance.
At the moment each frame takes about 1 hour, which to me seems crazy high.

I´m sort of inexperienced, so I might have done things that slow down the whole render process, so feel free to have a look at it, any suggestions are welcome :slight_smile:

The animation is going to be presented with a projector at 4:3 ratio.
My experience with these things is that detail does´t show too well, plus the resolution is limited to what the presenter´s laptop is able to show, so perhaps 1600x1200 is good enough a resolution?

As any artist, I´m not yet satisfied with the look, materials, lighting etc.
but I´ve decided that this is what I could do with the time and skills I had at the moment.

I´ve used Blender 2.78c with Filmic
Blend file here.

Test video for the presentation here. (153mb)

Some renders from the project:

By cutting down frames for one. In the video, first animated shot could be much shorter. Faster and/or shorter movement to the door, which could have electrical room signs on it, open the door, and cut just as the camera moves in. That should be enough to show the things happen in the electrical room.

That could cut to the next shot, rotating scene, and should only need to render one rotation and repeat that in post.

Should be able to utilize baking to speed up the animation rendering

Of course highly reflective materials would need good reflections, maybe rendering those on separate render layers and using samples override option on either to give low samples for the baked elements.

First shot:
The corridor is long and black cause this gives time to display the name of the project on the screen before the door opens into the lit room, this “darkness” does´t show in the animatic. But yes still, I guess I could cut some frames and maybe slow down the clip in post.

Rotating scene: Yes, I intend to do just one rotation and then duplicate it in post.

The last shot is long and slow, but the guys is gonna describe a lot of things while it plays, so the shot has to be a little slow, I will consider making it faster and slow it down in post, but you can only slow it down so much before it is noticable that frames are missing.

I will take a look at baking, however many objects does not have textures on all faces, I guess you need that for it to bake? I can of course add some :slight_smile: Will take a look at the video.
Will you save time of you´re baking just some objects and not all?

Reflective materials:
What do you mean “highly reflective materials would need good reflections”?
I´ve never worked with rendering on separate layers with different samples on each, will google a little on this as well.

Thanks for feedback JA12 for points in the right direction :slight_smile:

By the way, baking… if I bake the textures, isn´t that just usable when doing animations where only the camera moves? As light, shadows, reflections etc. will change during an animation, the baked textures have to change… or am I misunderstanding.
Could use it for the rotation shot though :wink:

You can give a shot at the new upcoming denoiser into the niglthy of the next 2.79. If your rendering problems are first of all getting rid of the noise and fireflies…
Grab your os in the first five builds, the denoiser is in the renderlayers panel.
I haven’t tested the denoiser with animations yet but Filmic is also there by defaut!

Also I suggest to render single pngs and encode them lately, render in every computer with both CPU and GPU by using the “placeholder” and without “overwrite” options under the destination folder of your output

Is any of that working for this problem?

You should always start by doing “OpenGL Preview” renders, with “stamps,” and take these to a video editor to “cut the final(!) show together” … before(!) you final-render anything. This will tell you exactly what frames you need to render.

(Yes, this workflow has been referred-to as, “Edit, then Shoot.” An OpenGL Preview render will correspond exactly to its final-render counterpart.)

OpenGL is cheap. Therefore, shoot more footage than you think you need, from more cameras (all carefully labeled). Sure, you’ll leave most of it “on the cutting-room floor.” Cut, cut, cut to produce a tight, sure-footed show. That’s what you’ll then start to render: “the final cut.”

Then, try to break each shot down, planning on heavy use of compositing. For example, if the camera doesn’t move, only one background plate is needed. Likewise, if the camera stops, only one frame is needed at that spot.

If several objects move independently, consider a shot-breakdown that does each one separately. (Don’t forget “shadow catchers.”)

Render to MultiLayer OpenEXR files except for the “final cut,” which can simply be OpenEXR. You will then produce all required “deliverables” from that directory.

If several things are moving in a frame, consider reasonable ways to render them more-or-less separately. (Don’t forget “shadow catchers.”)

Freely combine available rendering methods: OpenGL/Game, BI, Cycles.

After all components have been rendered, use compositing to combine them into finished frames and to make final adjustments.

If a render seems “hosed up,” keep it anyway.

1 hour does seem excessive based on how your scenes look.

You could try one of the experimental builds with denoising and AO simplification. I used one of the builds and got the BMW benchmark scene down from a little over 1 minute to 14 seconds on a 980Ti (almost 5x speedup).

If you don’t want to go down that route - some things you could try.

Turn of caustics.
Use clamp direct and clamp indirect to minimise fireflies.
Use as few bounces as possible
Make sure the noise seed is set to animate with the frames so that whatever noise does remain - isn’t ‘offensive’ to the eye (the clock icon in the sampling tab).
Use as few samples as possible.

and most importantly - make sure your tile size is appropriate for GPU rendering (use the autotile size plugin)