Author Topic: Grass scattering  (Read 19805 times)

2015-05-24, 17:35:19

fla

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Hi to all!

I'm starting to test recently published Corona alpha2 for Cinema. I must say I'm really impressed!
Today I was playing around with grass scattering (with surface Spread) and I have a question for anybody that has some experience with it.
It's precompiling really fast when I keep number of render instances low (p.e. when I cover a filed aprox 20meters from camera) but when I try covering aprox 40meters the "Preparing" part goes on and on. I'm asking this because a friend that uses Max + Corona does not seem to experience the same long "Preparing" pre-rendering time. I'm wondering if anybody could light the subject a bit.

I'm attaching a preview image - it only took 2min to render this, which is pretty fast (I'm covering aprox 20m radius around the camera - actually only the cone area). But increasing the size just increases the time really drastically (to about 20min of Preparing time).
Is there anything I can do to speed it up?

The grass patch has 800 polys, it's not that heavy.

I'm using i7 3930K, 32gb ram

cheers,
matej
« Last Edit: 2015-05-24, 17:41:16 by fla »

2015-05-25, 00:24:18
Reply #1

cecofuli

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Maybe precompiling in C4D isn't multithread. Look at the CPU usage.

2015-05-25, 10:40:12
Reply #2

fla

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I've checked. CPU usage is around 10-15%. Ram around 8Gb. Which is comparable to vray readings when rendering(precompiling) the same scene.
« Last Edit: 2015-05-25, 11:09:34 by fla »

2015-05-25, 12:06:14
Reply #3

maru

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Are you using textures on these grass blades? Could you check without? Maybe this is the case?

2015-05-25, 12:32:15
Reply #4

fla

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I've tried rendering without the texture on the blades - I'm afraid preparing time stays the same as before.
I'm attaching the whole scene.

cheers
m

2015-05-25, 14:43:57
Reply #5

burnin

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Yes, the problem is in multiplying too many by plugin (even MoGraph cloner would have problem spreading 7million objects) that's an old limitation of cinema (it can handle polygon counts but not too many objects).

Edit: Deleted useless mumbling
« Last Edit: 2015-05-25, 14:57:43 by burnin »

2015-05-25, 14:46:06
Reply #6

fla

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2015-05-26, 11:42:15
Reply #7

fLuppster

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Yeah, C4D is really bad in handling many objects, i had the same problem. I will soon purchase carbon scatter to get some multicore support.

But in your case its easy to fix: just increase the size of your grass patches. It should be no problem, because your ground is pretty flat. I had ~1 mio. grass patches in one scene, it was a nightmare...

2015-05-26, 12:01:16
Reply #8

fla

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Carbon Scatter is multithreaded? It looks like a good piece of software.
Does anybody have experience with it?

Yes, I could easily make a biger grass patch, but the result isn't as good as having small patches and having control over size and color variations.

2015-05-26, 16:43:01
Reply #9

pBarrelas

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I use SurfaceSPREAD and personally I think it works a lot better than the built in a Cloner object.

2015-05-26, 22:24:17
Reply #10

fla

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If it's really Cinema that can't handle large number of clones than even Carbon Scatter might not help?
I really hope Maxon would tackle the problem in the next version.

@pBarrelas: I like SurfaceSpread too. It has many usefull options with scattering, many of which Mograph doesn't. I mainly use it for grass.

2015-05-26, 23:20:40
Reply #11

kod3d

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I use carbon scatter a lot and it has saved me when it comes to cloning vegetation and other stuff! It can handle much more than the native cinema cloners and it is so much smoother with much more intuitive controls when it comes to spreading vegetation. You can use splines etc. which is really handy. I can clone a hole field with grass and it can handle it just fine. Also I don't work for them, I just like it..

:)

2015-05-27, 12:33:01
Reply #12

fLuppster

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Sure, SurfaceSpread is nice and has many useful options, but its not really faster than the mograph stuff. Thats the big advantage @ CarbonScatter.

I had a bug with SurfaceSpread: It was not possible to populate the patches with a normal alignment. So i had to change to mograph cloners. But C4D and scattering is as we already found out a pain in the ass... To be honest, i dont think that there will be changes very soon, because the viewport core in cinema unfortunately supports just a single core. They need to change the whole C4D core, which would take a long long time.

2015-05-28, 09:28:50
Reply #13

fla

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Thanks guys!
Nice to hear that Carbon Scatter is the way to go.
I'm downloading the trial right now.
Will get back with feedback.

cheers
m

2015-06-02, 22:43:14
Reply #14

Han

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A lot of people wrote a lot of nonsense.
In C4D several amended versions in different modules of the program for multithreading.
When using Corona at the moment there is a problem with the preparation stage. Remember this is only the Alpha 2.

Attached image Made in the standard render.
All objects are unique. Render Instance were not used.
Polycount - 30M   Time -1,21min
« Last Edit: 2015-06-02, 23:50:18 by Han »