VRay Multimatte Renderelement free download!!!!!!!

[dimo]

Yes,

we are moving servers. Will be down for a couple of days.

Sorry for that. But as Thorsten said its in the final 1.5

Best regards,

Dieter

[tricky]

I may have found an issue with multimatte/max8/vray1.5, but it needs further testing.

I am rendering a scene 4000x3000 pixels. It has 9 multimatte channels in there for 9 different material mattes. When I click render, max crashes.

If I render the same scene at 2000x1400 pixels, it renders fine, but upping to 4kx3k crashes. If I disable the render elements, it renders at 4kx3k just fine.

If I reduce the number of multimatte elements to 3, it renders at 4kx3k without a problem.

Is there a maximum number of multimattes that can be used safely?

[instinct]

no, but you cannot render too many at too big sizes to a memory framebuffer. It's a simple calc actually. The framebuffer has to keep an uncompressed float image in memory for each element.

example given :

You render at 4kx3k that means one RGB layer needs :

4000x3000x32x3 = 137mb if i didnt fuck up unit conversion :P

so now you got 9 elements = 9x137mb = 1.2GB alone for the renderlements.

To prevent that you can turn off the memory framebuffer and it will render fine. Note that you have to untick "Get Resolution from Max" and set the Max resolution to 1x1 pixels, otherwise max itself will still reserve memory for it's own VFB.

Regards,
Thorsten

[tricky]

Aha - I see. That explains a lot.

[dbuchhofer]

to go one step further...

This same exact calculation comes into effect for each and every texture that is included in the scene. Which is why we try and keep our textures to appropriate sizes!

Some examples:

The basic calculation for megabytes

Length * Width * BitsPerChannel * NumberOfChannels = bits of ram per image

512 * 512 * 32 bits per channel * 4 channels (Red, Green, Blue, Alpha) = 33554432 bits = 4MB

1024 * 1024 * 32 * 3 channels (RGB, but no Alpha) = 12 MB
1024 * 1024 * 32 * 4 channels (RGBA) = 16 MB

2048 * 2048 * 32 * 3 channels (RGB, but no Alpha) = 48 MB
2048 * 2048 * 32 * 4 channels (RGBA) = 64 MB

4096 * 4096 * 32 * 3 channels (RGB, but no Alpha) = 192 MB
4096 * 4096 * 32 * 4 channels (RGBA) = 256 MB

Conversions provided by : http://www.matisse.net/bitcalc/?inpu...otation=legacy

THAT’S JUST THE RAM TAKEN UP BY A SINGLE TEXTURE OF THAT SIZE. 1x4096 textures takes up 256mb of ram! Image size on disk has no effect on how much ram is taken up by the texture, it is only the pixel dimensions that define RAM usage.

[tricky]

...good job we have 4GB then!!!!!

[vlado]

You need to double this amount of RAM if you use Mip-Map filtering, and quadruple it if you use Summed Area.

So a 4096x4096 image would actually take 512 MB of RAM. In 4 GB, you can fit only 8 of these.

Best regards,
Vlado

[dbuchhofer]

good thing life is much fast with bitmap filtering off 95% of the time

thanks for the info.. forgot about filtering!

[tricky]

good thing life is much fast with bitmap filtering off 95% of the time

So any bitmap you use, you tell max to have 'none' as bitmap filtering?

[vlado]

good thing life is much fast with bitmap filtering off 95% of the time

So any bitmap you use, you tell max to have 'none' as bitmap filtering?

Well, I won't recommend turning filtering off completely; it prevents textures that are far away from flickering - otherwise you'll need very high AA settings to get rid of this.

Best regards,
Vlado

[k-arts]

Multimatte

Hi there,

i tried to give Dino's MultiMatte a shot.
Now a little problem came up.

I used three balls intersecting each other. Now i want to form an alpha in compositing for all three at once to check if MMW would work, but i get those lines in between! Even if i turn the AA off they are still there. Premulti against background can't be the solution.







... anyone? i am kinda lost here!

thanx in advance

Lisa

[dimo]

Hi,

1. You have to add the channels together rather than comp them with a merge. Shuffle each channel to an alpha and add all those alphas.
2. You have to work in linear color space.
The result will be the same as the original alpha then.

Best regards,

Dieter

[k-arts]

i'll get right on it! Thx so much

[sv]

can i firstly say this is an amazing script - so handy; you've really opened my eyes to compositing better.

My question is; is there any way to exclude an object from affecting this? I have an object behind some glass, but of course the glass blocks the object behind from showing up in any channel. Is there any way to make the glass not affect the objects behind?

[k-arts]

wasn't that discussed above? But i'am not sure! But sounds familiar!