Creating Grass with Mograph and Vray

Here is the development of the grass patch (seen from a rather great distance) inside Vray. The rendering times had to stay below 5-7 minutes per frame, using GI.

(click on image to see the WIP animation)

Here are some remarks:

• Visibility tag for distribution of the grass to set to boxes. I needed a LARGE number of instances for this sphere (approx 15000)
• General orientation of the grass should be upwards - I used a target effector but weighted it lower than 100% to get direction - as last effector in the list.
• 2-sided materials in Vray made the render considerably slower (factor approx 2-3) and at this distance translucence doesnt matter much.
• Other cloners to redistribute variations and single plants.

Next step would be SurfaceSPREAD plugin, but I didn't have it at this time.

The visibility tag and mograph

For scenes with a very large number of cloned objects I have used the visibility tag, to specifically control the number of clones visible on screen, mainly because my graphics card is rather old.

Unfortunately, the detail in visibility can not be switched off for rendering. This means, that it has to be switched off manually before rendering.

In combination with the "Render Instances" option in the Cloner object the behavior is slightly harder to predict.

Thoughts about motion blur

Below is a shot that shows all the potential problems I can have with motion blur. This is a parallel camera motion to the movement of the white ball, which itself is moving at fast speed across the table.

This particular frame was rendered with the physical renderer. Unfortunately, there is no postpro control on the motion blur, and the frame took 30 minutes to render - highly impractical.

Watch the area, where the two balls overlap - I think that the physical renderer doesn't get it right, but I'm not 100% sure, how the motion blur phenomenon would work on a real cam in this case.

So, we have at least three different objects moving at different speeds

• the white ball (strong movement)
• the other balls (motion blur through camera)
• the table texture with different motion blurs depending on distance from camera.

So I am left with the following solutions to get a good motion blur:

• High importance: physical renderer and go to a render farm
• Pro: perfect(?) motion blur, physical accuracy
• Contra: Problem with setting up the other passes (more research needed)
• Low importance: plugin in AE 
• Pro: adjustable in post, might catch the above problem
• Contra: Doesn't look perfect, complicated object buffer handling, more overhead

Concatenating movies

After a long search I've come across QTCoffee link - a very useful collection of command line tools.
You can easily combine several quicktime movies to a single one, especially for technical trailers and black at the end this tool comes incredibly handy.

Many of the digital playouts I have to produce need different setups.

Here is an example:

catmovie
Bars.mov Black.mov Content.mov Black.mov
-self-contained -force-same-tracks
-o Outputmovie.mov

First tests seem very good - I hope I can use it more.

First caveat: Although concatenated movies of different formats will play back in QT player, after another conversion step the audio was garbled. I therefore use ProRes only before concatenating.

HDR conversion inside C4D

I have had some ooooold HDR probes sitting somewhere on my harddrive - one day I would buy HDR Studio and convert them...

But actually C4D can convert probes and crosses (HC and VC) in the image viewer to the C4D Longitude/Latitude format for skies. It does it automatically, you open the file and - le voila. A great little gem hidden away!

Sorting multi-pass files into directories

The problem of the multi-layered file was that EXtractoR takes forever to extrude eg the motion vector channel, even if the file is on the local hard drive (possibly due to the unzipping) -

the problem is also described here:
http://area.autodesk.com/forum/autodesk-3ds-max/lighting---rendering/exr-compression-and-ae/

I will go for the recommended route and split up the files again. It might also help me with the previews. But we will see for that.


Found the AE Plugin "Immigration" here:
http://aescripts.com/immigration/
for importing files - I would like to prefer to sort the passes in different folders, after the render

http://www.linuxjournal.com/article/8919
got me going with a rather simple script.

So I came up with this ultrasimple script:

find . -type f -print |
while read -r pathname; do
   
    filename=${pathname##*/}
        
    # very unclean because hard-coded 0000.exr ending but good for now
    new_dirname=${filename%????.exr}

    if [ ! -d "$new_dirname" ]; then
        mkdir -p "$new_dirname"
    fi
    mv "$pathname" "./$new_dirname/$filename"

done

OpenEXR and R13

I am changing my pipeline to accomodate OpenEXR for the following advantages:

• All channels in one file (no messy directories)
• 32-bit 
• lossy compressions available 

These are the downsides

• You cannot re-render just one channel (ie a mask), but from experience I have rarely only rendered one channel, plus it looks like C4D would have to render to whole image anyway, so not a lot is gained. For special cases, such as masks I will generate subdirectories and they are highly compressed anyway.
• No 16-bit support in R13 (maybe, they'll bring it back) - so the only option is to go with 24bit lossy, which according to forums will just truncate 32->24 bits and rezip the file. For my purposes this is more than enough, as I don't layer a lot of stuff.
• ExtracToR in After Effects is rather slow, but this seems to be related to the file transfer.

For my test frame, I was faced with those sizes (I didn't measure multichannel here)

• All compressions RLE, ZIP, ZIP16, lossy PIZ wavelet, etc around 20-24 MB
• The 24B format comes in around 12 MB (ie half)
• A 16-bit PSD file comes in at around 12.4 MB - so 24BLossy is the way to go.
• 8-bit DPX is 6.2MB

So with 24 bit lossy format I gain more than enough control. 

Copying mograph simulation to high-poly object

It is not straightforward to bake a simulation in an array of dinamically simulated mograph objects. This is my way of doing it:

1. Bake the simulation in the cloner (it doesn't matter if the dynamic tag is on the cloner or the object)
2. On the final object create an expresso tag and add a node for the Cloner object and the Final Object.
3. Add mograph data node and connect global matrix to the Final Object global matrix.
4. Step through the index manually until you've arrived at the object.

Alternatively, it might be easier to find the object index with Mograph selection, but I couldn't figure out where the information on the selected mograph clone index would be displayed.

Lighting Setup and Balls on Table

 First lighting setup - the balls should be able to pop from the background, so I've added a white reflective band from the outside which helped a lot. Might be slightly too dark, but as looks rather realistic.

Pool Table Modeling

Added another 2 hours. Still working on the lighting of the whole thing. Torus is added for shadow measuring and color bounce.

First take on pool table

After about 1 hour of reference searching and 1 hour of modelling.

 

Already looks quite ok - some issues with Hypernurbs and the end parts of the table. Need to remodel some of them. 

First Material Tests

Here are some material testss. The scratch texture must be hold separately and in much higher resolution. Rendering times in 32-bit were around 10 minutes (not saved in OpenEXR format) - standard lighting with HDRI environment (garden, outdoors) - no color correction. White should be more off - taking that into the shader.

Some reflection work for the balls - very carefully applied. Ball whites are taken to off-white improves the look greatly. Reducing accuracy on area shadows plus AA on 1x1,4x4 and 5% th gives an enormous speed up. Rendering time went down to 6:30.

Encore PAL Widescreen DVD Menus resolution

How to create best resolution menus.

Create the menu in encore and edit Menu in Photoshop. Scale to 1050x576 (weirdo Adobe Format) and set Pixel Aspect Ratio to Square, save and voila.
In Encore take out the Ratio correction in the menu viewer (small icon lower left)

Reflecting Invisible Floor

To generate a reflecting ground, that can be composited on a blackground.

Put a plane (it doesn't have to be a floor) under the objects and make it 100% transparent, use the "additive" option. Add reflections to your liking. Only the reflections remain in the alpha, the floor is gone.