Shadermixer Brick:Ray Marcher...

mjc1016

Anyone have any info on the Ray Marcher brick...the doc page is a bit sparse...

http://docs.daz3d.com/doku.php/public/software/dazstudio/4/referenceguide/interface/panes/shader_mixer/bricks/dzraymarcherbrick/start

Mattymanx

http://zigraphix.com/dazdocs/shader_mixer_brick_docs.pdf

Ray Marcher adds variables for volumetrics. ShaderRayMarchPoint, CurrentRayMarchPoint. This is the looping brick. Rather experimental

Also see here - http://www.pharr.org/matt/notes/sig01c48.pdf - Page 107

mjc1016

Yeah, basically, I guess I'll just use the smoke brick...I can't get the ray marcher to do more than blotches.

Pendraia

I don't know much personally but was wondering if it relates to volumetric did Age of Armour use it in his cameras? If so that may give you examples of how to use it...just a thought! ; )

Rareth

According to the Shader Mixer Bricks Docs PDF that was linked, the smoke brick is a wrapped RayMarcher
but does not give much more detail than that..

Age of Armour's Atmospheric Effects Camera package doe use the Smoke Brick in the Volume camera.
he did a really good job with the volume side of the camera shader.

Pendraia

Rareth said:

According to the Shader Mixer Bricks Docs PDF that was linked, the smoke brick is a wrapped RayMarcher
but does not give much more detail than that..

Age of Armour's Atmospheric Effects Camera package doe use the Smoke Brick in the Volume camera.
he did a really good job with the volume side of the camera shader.

I wouldn't expect to see much in the Docs relating to the network but it should be possible to import the camera into shadermixer and view the network that would allow him to see how it fits into a network.

mjc1016

I was looking at the Ray Marcher, by itself, because the smoke brick is rather slow and I was looking for an alternative way of achieving the same thing, that may be a bit faster/optimized for a specific task.

Pendraia

mjc1016 said:

I was looking at the Ray Marcher, by itself, because the smoke brick is rather slow and I was looking for an alternative way of achieving the same thing, that may be a bit faster/optimized for a specific task.

Aahh, should have known that you would already have checked it out...: )

Sorry I can't be of help.

Rareth

the Ray Marcher plugged into the volume root brick doesn't appear to be any faster than the smoke brick, and the settings are a bit more obscure in trying to figure out the right balance for the look you would want and render speeds.

Note* this is a camera shader,

Pendraia

Rareth said:

the Ray Marcher plugged into the volume root brick doesn't appear to be any faster than the smoke brick, and the settings are a bit more obscure in trying to figure out the right balance for the look you would want and render speeds.

Note* this is a camera shader,

would it work with other shaders? I was thinking it was a brick for a Camera shader...

Rareth

you can put it on a surface shader, but you won't get volumetric effects, I've tried that..

can make some interesting surface effects with lighting by doing it too.

Pendraia

Rareth said:

you can put it on a surface shader, but you won't get volumetric effects, I've tried that..

can make some interesting surface effects with lighting by doing it too.

Thanks...I've just been playing nothing serious as I really haven't a clue how to use this but haven't come up with anything worth posting.

Rareth

oh I haven't done much worth posting myself, just tests with a few primatives, a spot light.

mjc1016

Well, some results from my recent playing...one of the problems with speed I was having...environmental lighting. With the RM brick...DON'T DO IT!

Not that it is actually wrong...but be prepared for it to take DAYS to render....on my system it was less than 1/4 done on a 1000 x 800 render, after 14 hrs. So...a bit over 2 days to finish...I could render it in Luxrender in less time. Yes, the settings are much less 'intuitive' and harder to get a good balance, than with the smoke brick. Like I mentioned, blotches were what I was getting, but it turns out, after playing with the settings more, that it was because of the lack of having the right balance of settings.

Rareth

mjc1016 said:

Well, some results from my recent playing...one of the problems with speed I was having...environmental lighting. With the RM brick...DON'T DO IT!

Not that it is actually wrong...but be prepared for it to take DAYS to render....on my system it was less than 1/4 done on a 1000 x 800 render, after 14 hrs. So...a bit over 2 days to finish...I could render it in Luxrender in less time. Yes, the settings are much less 'intuitive' and harder to get a good balance, than with the smoke brick. Like I mentioned, blotches were what I was getting, but it turns out, after playing with the settings more, that it was because of the lack of having the right balance of settings.

I think decreasing step size and increasing the number of steps will help reduce the blotchy (blockiness) thats occuring, the quality slider in Age Of Armour's volume Camera pretty much does the same thing.

I've tried adding some of the volume shaders to a light but nothing happened, so either it doesn't work that way or I'm missing something.

mjc1016

With a volume camera, every light used in the scene is used for calculating the effect...hence the tremendous increase in render time with an envlight. With a defined volume, only the lights attached to that volume should be used for the calculations. That's the way it appears to work with UberVolume

Rareth

mjc1016 said:

With a volume camera, every light used in the scene is used for calculating the effect...hence the tremendous increase in render time with an envlight. With a defined volume, only the lights attached to that volume should be used for the calculations. That's the way it appears to work with UberVolume

yeah but I think uber volume is scripted from the shader builder, the bricks in the shader mixer aren't quite so versitile,

Richard Haseltine

As far as I know all of the uber shaders are custom code, though I think omniFreaker did create the shader code behind at least some of the bricks in Shader Mixer.

Rareth

well I figured out something, if I use a Spot Light from the shader mixer and just plug in the shadow brick, I can have the inner and outer angle parameters and set the light distribution between them (still working on that, need reread up on spotlights in the book)
so if I use that light with the volumetric camera I get this..

Pendraia

IIRC Yacomo stated in the Global illumination thread that some ShaderMixer networks will not show up properly without a Shadermixer Light and Camera in the scene.

mjc1016

Anything that requires photons...caustics and such, needs a surface, camera and sometimes light from SM. That's because the 'standard' DS cameras and lights have those features disabled...or more properly, removed. Basically with the photon mapper/caustics root settings added where appropriate, you get the 'standard' 3Delight lights/cameras...or at least that's what it looks like without seeing the actual code behind the bricks. All the volume effects should be 'visible' with a standard camera...

Pendraia

mjc1016 said:

Anything that requires photons...caustics and such, needs a surface, camera and sometimes light from SM. That's because the 'standard' DS cameras and lights have those features disabled...or more properly, removed. Basically with the photon mapper/caustics root settings added where appropriate, you get the 'standard' 3Delight lights/cameras...or at least that's what it looks like without seeing the actual code behind the bricks. All the volume effects should be 'visible' with a standard camera...

Fair enough...nice to have it explained further.

thanks

Pen

sriesch

Thanks for the links at the top! I thought I actually had the right documentation link, but it was pointing to something else (maybe an old page?) that had almost no info. Now I have a lot to go read up on!