Ambient occulsion

[ZFact]

Hi;

 

I am wondering is there some way of

rendering out a 3D still in Final Render 2

then rendering same image in Cinema 4D

with AO... and just white materials

and somehow layer the 2 over each other

in photoshop? If so how?

[STRAT]

aye, thats how i do things

 

1) render out your colour still in FR as normal.

2) then un-assign your scene and mesh of all materials. you can delete all lighting rigs too as they're not needed.

3) create a new material with just a white illuminance channel value.

4) apply this material to all in the scene

5) under the AR's render settings, goto the ambient occlusion tab and click on 'apply to scene' and there you go, hit render

 

6) i'll use typical AO settings for internal renderings as -

 

min ray lenght - 0mm

max ray length - 500-1000mm

dispersion - 100%

accuracy - 50%

min samps - 10

max samps - 75

contrast - 0%

 

and make sure AA is switcherd on when rendering.

 

7) to overlay in photoshop, open up your 2 renders (the colour and ao images you've just done)

8) copy and paste the AO image into the colour image and it should fit directly over the top if you havent changed your camera angle.

9) make sure the AO image is above the colour image in the layer stack, then change the AO's layer mode to MULTIPLY, with about 50% transparency too.

[ZFact]

your a legend... what settings do you generally

use for external renderings

[ZFact]

aye, thats how i do things

 

1) render out your colour still in FR as normal.

2) then un-assign your scene and mesh of all materials. you can delete all lighting rigs too as they're not needed.

3) create a new material with just a white illuminance channel value.

4) apply this material to all in the scene

5) under the AR's render settings, goto the ambient occlusion tab and click on 'apply to scene' and there you go, hit render

 

6) i'll use typical AO settings for internal renderings as -

 

min ray lenght - 0mm

max ray length - 500-1000mm

dispersion - 100%

accuracy - 50%

min samps - 10

max samps - 75

contrast - 0%

 

and make sure AA is switcherd on when rendering.

 

7) to overlay in photoshop, open up your 2 renders (the colour and ao images you've just done)

8) copy and paste the AO image into the colour image and it should fit directly over the top if you havent changed your camera angle.

9) make sure the AO image is above the colour image in the layer stack, then change the AO's layer mode to MULTIPLY, with about 50% transparency too.

 

 

Just tried it out using a couple of cubes.... it works a treat... great

wee trick... thanks for sharing it.

[STRAT]

hey no probs.

 

for externals i generally use the same settings, only i'll alter the max ray length to something with a bit more spread because we're usually further away. something maybe up to 3000 mm maybe.

[Frosty]

Strat, what happens to objects with alpha maps (ie. trees)? If you delete all of the materials that define the leaves, doesnt the AO pass get a bit messed up?

[STRAT]

well AO is a mesh based render process anyway, not texture based, so AO wont work as hoped with alphamapped objects weather they have their alphas applied or removed. i usually exclude these from the AO solution during rendering.

[AJLynn]

Won't AO work with your alphamaps if you use Evaluate Transparency? Also, if you're already using FR2, why not use FR2 AO? I haven't done a heck of a lot of testing but it seems a lot faster. You can get it in the shader tree by wiring an AO node to a Standard material's self-illumination.

[STRAT]

Won't AO work with your alphamaps if you use Evaluate Transparency?

 

you are correct, i neglected to point this out in my explanations above.

[ZFact]

Won't AO work with your alphamaps if you use Evaluate Transparency? Also, if you're already using FR2, why not use FR2 AO? I haven't done a heck of a lot of testing but it seems a lot faster. You can get it in the shader tree by wiring an AO node to a Standard material's self-illumination.

 

Im still trying to get my head around setting up shader trees in fr2.

It prob seems more complex than it really is but when you look at

some of the free shader trees on the cebas site they are like

a printed circuit board... i personally wouldn know whats doing what.

 

Its a good idea also to utilize the strengths of both programs where

possible... but im only saying that because my knowledge in FR2

is somewhat limited.

[STRAT]

the only trouble with AR's AO is that it can be just as slow as it's GI

[ZFact]

true... if i find me a minute or 2 spare i might have a futter around

with FR2'S AO... you apply it to separate materials though the way

you use to do it in cinema... its very handy being able to apply

it to the full scene... but i suppose you have less control over it

that way... perhaps thats why its so slow. as your AO'ing things

in the scene which simple wont benefit from it

[AJLynn]

Pedro - making this shader tree is very easy. Just 2 nodes from the list on the left - Standard and Ambient Occlusion. You need to use the red dot on the left of the Standard box to enable an input for Self Illumination, then drag Color from AO to Self Illumination to make a link, and do the same to link Standard's color to the node on the very right of the Shadertree window. You can click the AO node to change the AO parameters, and the Standard node to change the material's other parameters. You can use pretty much everything in there in a way that's analogous to Cinema's material systems, then when you get comfortable with it try to figure out how the heck the Cebas forum people came up with the more complex ones.

[ZFact]

i'll give it a whirl... i think those ones on the cebas scared me a bit.

I suppose they dont have have to be as complex as all that.

 

Thanks for the advice Andrew

[ZFact]

Pedro - making this shader tree is very easy. Just 2 nodes from the list on the left - Standard and Ambient Occlusion. You need to use the red dot on the left of the Standard box to enable an input for Self Illumination, then drag Color from AO to Self Illumination to make a link, and do the same to link Standard's color to the node on the very right of the Shadertree window. You can click the AO node to change the AO parameters, and the Standard node to change the material's other parameters. You can use pretty much everything in there in a way that's analogous to Cinema's material systems, then when you get comfortable with it try to figure out how the heck the Cebas forum people came up with the more complex ones.

 

Ok... iv give it a whirl... iv got the AO and the standard sorted... now iv

tried to include a brick map... pulled in the bitmap node and linked

it up to the diffuse colour node of the standard... looks good..we

got a brick shader with AO... this is where i get stuck.... how do

i include some brick bump to the shader?

[AJLynn]

Bump seems to me a bit more complicated than it really needs to be. You need a Bump2D or Bump3D node, mainly depending on what it's using as input - e.g., a Cinema 3DNoise map goes best with a 3D bump. Wire your input to bump node's input, and the bump node's output to the Normal input of the Standard.

[ZFact]

Bump seems to me a bit more complicated than it really needs to be. You need a Bump2D or Bump3D node, mainly depending on what it's using as input - e.g., a Cinema 3DNoise map goes best with a 3D bump. Wire your input to bump node's input, and the bump node's output to the Normal input of the Standard.

 

The bump im looking to get is for the mortar joint in the brick work

to make it appear recessed. If tried wiring the 2d bump to the normal

of standard... but in cinema you have to stick in the black and white

bump map into the bump channel?

 

Any ideas for same in FR2

[AJLynn]

Are you using bitmaps or procedurals for the brick? You can use a Bitmap node and load an image file, then wire it like this:

 

Bitmap---->Bitmap2Normal---->Bump2D---->Standard.Normal

 

You can get the same effect procedurally by setting up a C4D_Tiles node with a Bricks pattern, changing the color swatches (I forget whether you need white on black or black on white) and going:

 

C4D_Tiles---->Bump2D---->Standard.Normal

 

You might need to adjust the values of black and white to get the bump amount. There's another way of adjusting that that involves adding another node in the chain, but I forget what to use.