Indigo Renderer Forum

Hi All,
We plan to add some scattering presets for the SkIndigo scattering: http://www.indigorenderer.com/forum/vie ... 17&t=13175

It will work a little bit like the material presets - you click 'add preset' in the SkIndigo scatter settings, and a gallery of scattering images is displayed in a dialog, you pick one, then the components and settings for that scatter are loaded into the scene.

So we need some Sketchup components for presets.

A single preset would consist of
* One or more SketchUp components (saved as .skp) files.
* scatter settings (density, evenness, height variation etc..)

So for example, to make a grass scattering preset, we would need a few grass clump components, and maybe a flower component or two.


Detailed requirements:
* Components should be saved in SketchUp 8 format for compatibility reasons.
* Component models and materials should be high quality, and optimised for scattering.
File size should probably be <= 5MB.
* Authors must be happy with licensing their components under a creative commons licence: http://opensource.org/licenses/bsd-license.php



If anyone would be willing to contribute some components for this, that would be awesome.
There will probably be a period of testing and feedback for the scattering presets, where we work out good file size guidelines, settings etc.., but we may as well get started now

A sketchup only feature?

Oscar J wrote:A sketchup only feature?

Well, SketchUp models can be exported to Indigo format (of course), so can be used by other exporters.

Oscar J wrote:A sketchup only feature?

The drawback of maintaining multiple tailored exporters is that much work is needed to maintain them, and features often can't be simply "recycled" for other exporters...

But Oscar has as a point here, why bother in creating sketchup based presets, please consider PIGS based presets, that could be shared easily over multiple 3D apps, once scattering is supported there!

I'll get to work on some..!

I guess the dandelion is too detailed?
I can do some basic weeds, buttercups, clover, etc.

Thinking about grass types (from my temperate climate region, anyway):
Lawn
Pasture (rough, more large weeds)
Meadow (longer grass, more flowery)
Muddy grass (for hillsides and damp areas, some fallen leaves)
Fairway (near perfect)
Savannah (long wavy grass, more brown)
[artificial is OK with a material]

Other common ground cover types:
Dirt (soil with small stones and twigs)
Bark mulch
Beach (sand with shells, a little driftwood, etc
Riverbed (stones with larger stones, algae/moss, twigs)
Autumn (fallen leaves, acorns, beavers)

ak-sam: Awesome, any contribution is much appreciated.
The dandelion was SketchUp 2014 right?
Any chance you can use SketchUp 8?

Dandelion is *maybe* too complicated, would have to do some rendering speed tests to say for sure.

Edit: 'beavers', heh

Zom-B wrote:

Oscar J wrote:A sketchup only feature?

The drawback of maintaining multiple tailored exporters is that much work is needed to maintain them, and features often can't be simply "recycled" for other exporters...

But Oscar has as a point here, why bother in creating sketchup based presets, please consider PIGS based presets, that could be shared easily over multiple 3D apps, once scattering is supported there!

It's difficult enough doing scatter presets for one exporter, as opposed to all at once. Let's start with sketchup and see how it goes.

Also if anyone wants to supply models in OBJ format (with materials in Indigo format, or just textures) that would be helpful as well!

Clovers are attached - just a couple of simple ones for scattering, but maybe still too detailed?
I will work on a proper scattered Lawn or something. I think it will need 5 or 6 component types to make a realistic lawn. The Clumps must be small (a few blades) otherwise the centres scatter them across edges of paving etc.
The blades have to have enough curves so that we don't see a flat reflection (looks like white spots) - but can this be prevented by a material setting? I generally use Phong for leaves but maybe that is not ideal?

I'm happy to convert any files if people don't have sketchup pro. (can do OBJ as well).

A grass clump is attached

Clover looks pretty good, thanks.

As far as materials go, the best material to use for small-scale plant matter like this is double-sided thin.

Here's a render of a clover scatter mixed with my grass preset:

ak-sam wrote:The Clumps must be small (a few blades) otherwise the centres scatter them across edges of paving etc.

This is an interesting point. The problem with making the clumps just a few blades, is that it means a *lot* of instances will be needed to cover a large area.

Just in terms of rendering efficiency, grass clumps on the order of a foot across or so would probably perform a lot better. For example, a patch of grass 10cm x 10cm would require 1M instances to cover a lawn that is 100m x 100m.

If the clumps are just a few blades, then the clump area is probably more like 1cm x 1cm, which means it can only cover a 10m x 10m area before using 1M instances.

Once you start getting more than around 1M instances, scene building starts taking more than a few seconds, and rendering time probably slows a bit.

One possible solution is to have large clump models and small clump models, and use the large clumps away from boundaries, with the small clumps near the edge.

OnoSendai wrote:One possible solution is to have large clump models and small clump models, and use the large clumps away from boundaries, with the small clumps near the edge.

This is my current work flow with the 'make crowd' plugin. Works OK for me but there is definitely some trial and error with overlapping the boundaries / over-spilling the grass area...

For sure one cool thing comes when we spend some time on it. I cannot expect extra cool result from a preset. Otherwise, where would be my knowledge?

I PM:ed Ono:

I suppose a material file couldn't support scattering? Like you assign a grass material and grass is automatically scattered in the correct scale.

He answered:

Hi Oscar,
this is something I have thought about as well.
It's definitely possible, we have initial support for it.

Sounds like a plan to me.