Ambient occlusion, how to?

[helgetjelta]

OK, the 3D tracking is done, the box and text is in and well. How do I get a groundlevel shadow now...

I've put in a light and a solid lined up. When blending to multiply I almost get it... but I've heard about Ambient Occlusion and the tutorial for flame shows how to turn the solid of via shaders node... but this one is not in Smoke... so how do we fake ground level shadows...

/helge

[BKM]

If you go to the OUTPUT menu in Action, you can activate AO there.

[helgetjelta]

Looks like I've missed something... Looks like AO is not what I need. But my shadow that is casted on a groundlayer, should be set to some other things... I try blend to multiply, but I have to keep my shadow in centre of the solid, or else I'll get a hard edge... 

/helge

[BKM]

What you need is a Projector. Which Smoke doesn't officially have.  That way you can project you scene on your ground plane and that plane will receive the shadow. 

Try this as a workaround...

Taake of 50% gray solid and use that as your ground.  Then use the Flame Blend mode - SPOTLIGHT this should remove the gray entirely. You may have to exclude this solid from all other lights and set an ambiant light to just light this solid.

[helgetjelta]

I tried with a colored frame set to 50 % grey... but I don't get it away. Still having edges...

/helge

[Grant.Kay]

Hi,

In the case of Smoke, you need to use the multiple outputs from action to create a beauty pass, and alpha pass and a shadow pass.

You use the EDIT OUTPUTS to set what you see in each render output from Action.

In the beauty pass, you hide the shadow cast and the receiving surface.  So it looks like the comp without the shadow.

In the Alpha pass, you output the alpha of your composited object.

In the shadow pass, you set the output to shadow and you should get a black shadow on a white background.

You wil now use two Comp nodes to recombine the passes.

The first Comp node, you combine the background with the shadow pass.   You done need an alpha, just use MULTIPLY and this adds the shadow to the background.

Using the second Comp node, you combine the object with its alpha on top of the background with shadow.

This will get you the result you want.

Regards

Grant

[helgetjelta]

Still struggeling... here is what I got so far:

I would like to have the shadow without the edges on my ground level solid. also the box should be transparent with shadows inside...

[Grant.Kay]

Hi,

From your screen grabs, you are trying to use blending mode to eliminate the ground plane but keep the edges.

The problem is that the ground plane surface is being affected by the lighting in action. There is no getting around this in Smoke.

The only feasible way is to use the Action Render Outputs and set up separate outputs from action for beauty, alpha and shadow which i mentioned in my last post.

Attached are my screengrabs of the different passes. Ill post another reply showing the COMP node combing the passes.

Regards

Grant

[Grant.Kay]

And here is the ConnectFX screenshot where I combined all the passes out of action into some COMP nodes.

Regards

Grant

[BKM]

---

@Anonymous_Smoker* wrote:

Hi,

From your screen grabs, you are trying to use blending mode to eliminate the ground plane but keep the edges.

The problem is that the ground plane surface is being affected by the lighting in action. There is no getting around this in Smoke.

The only feasible way is to use the Action Render Outputs and set up separate outputs from action for beauty, alpha and shadow which i mentioned in my last post.

---

You have to admit that the lack of a simple "No Shader" Shader Node would make a lot of this extra work pointless.
All he needs is to not have an image plane not affect by lights... Which is hat the No Shader Node in Flame does. 
I am not say Smoke needs eveything Flame has.. which has been beaten to death.  But I don't think the No Shader Node is that high end of a feature. 

Please pass that along.

[helgetjelta]

Thank you all for trying to help me out here. 🙂

But I have a bad feeling about Smoke. It is almost a teaser of Flame. All I hear is Flame can do this and Flame can do that. And Smoke can almost do the same... So it looks like it is an almost finishing tool. But just almost... I feel there is always something missing...

1. We now have 3D tracker, but no "No shader" so objects tracked into can not have a easily shadow on ground floor, workaroung; multicam output and combine , AFX does

2. Resolution, no unlimited (FCPX does)

3. Easy output of files/graphics/effects with embedded alpha. AFX, Motion and all others does...

Why is it like this ? Smoke is just, "almost".... right ?

/Helge

[BKM]

As Grant pointed out it is still possible to do what you want... it just requires more steps than flame. Trust me as a long time Smoke user I did get a little frusterated. But realistically you are only paying pennies for almost all the tools in Flame.

Not sure what yiu mean by resolution as Smoke can handle mixed res and all sizes. Yes the nodes must have matching res.

Smoke is all in one tool with conform, editing, and effects. As well as node based compositing. Its an all around tool.

[helgetjelta]

I know, I'm just a little frustrated... We have to do so much more all the times... there are workaraound for almost everything... 🙂 I know.

I'll give it some more then.

/Helge

Thanks

[christophzapletal]

Hey Helge !

One thing that might help you wrap your head around things : When using multiple action outputs, select the node and press Shift-C. That way you can make the multiple outputs visible in the CFX schematic and use them the way like Grant suggested.

Cheers, 

Christoph