ctrl_buffers

#301

:slight_smile: Offtopicā€¦
p_MegaTK have Input Normal that replace original normal. For example you may use mayaā€™s bump2d node (not mib_passthrough_bump_map or mib_bump_map).
Sorry, I have never try maya_bumpCombiner and mix8.Layer, but if it return normal it should work.

#302

Sorry for posting a kinda offtopic question here, but I found a new thread to be unneccessary.

Everybody here is talking about coverage data, label data and Shake. It sounds quite interesting but I have no clue how to use these files in Shake. Can somebody point me to a tutorial or a thread where this is discussed? I am very interested in what opportunities the coverage/label buffers have to offer.

#303

Hello thank you very much for this wonderfull shader!
I m trying to find a way to make all my shading passes with ctrl_bffers while keeping objects on separate layers. Is it possible? Or would you use a combinaison of ctrl_buffers with overrides based systems such as ā€œrender passesā€ (or maya 7 build in renderpass) ?
Ideally it would be great to get say up to 8 images for each object - keeping a good balance between render times and compositing freedomā€¦

Thanks a lot!

best regards

#304

IĀ’ve been able to get v1.5 working with the sample scenes on maya 7 and have tried to build my own scene with these shaders. But IĀ’m stuck on the buffer_api node! Can someone explain if its necessary, and how do you connect it up to make it work. IĀ’ve been unsuccessful.

When it does work its connected like

[buffer_api1]-----Labelize----->-----MiGeoShader-----[dummy_holding_GeoShader]

Can someone please explain what this connection is all about?

Thanx

#305

Hi,

I have my frame buffers working in maya 7. I had a question about setting up an RGB lighting pass.

I would like to have;

color pass ( usually use ambient light with ambient shading set to 0 )

is it possible to get a color pass ( only, no lighting ) from the ctrl_shading ?

RGB lighting pass on top of white diffuse surface ( three spotlights RGB )

It seems that to achive this I need to pipe each light into a mib_illum_lambert and then pass this into a framebuffer in the buffer store. But how do I achive my bumping. I have looked around the forums and have discovered the mix8Layer and bump combiner, but I am unsure of how to connect these up.?

matt

#306

oh my, i love this shader

but iā€™m having problem opening the tag (tt) file inn fussion, i donā€™t think fusion support it.
and i tryed using the openExr but maya just crashes when i render.

any ide how i can use a label pass rendered inn mentalray inn fusion?

#307

youā€™re not forced to use the .tt, just disable forcecorrectformat
in the output shader. and render out with the usual format you
use, mr will convert it for you giving you also a little warning about
that. or convert the tt via imf_copy utility.

/f

#308

Hi, Iā€™m a noob in this areaā€¦ can someone tell me whatā€™s the difference between ctrl_buffers and Maya 7ā€™s render layers?

#309

A render layer usually refers to a state held by the whole scene/image. For example, rendering a ā€˜colour passā€™ using a render layer would give you only the colour, for the whole rendered image. Also, passes/layers are rendered one at a time.

Framebuffers can be either related to the whole image (like a z-depth buffer, coverage buffer etc) or quite commonly just to one or more shaders/objects. Also, many buffers can be output from 1 single rendering of the image. Hitting render once could give you 5 different buffer images like colour, specular, a different shader for some objects, an occlusion buffer and aā€¦something-else buffer!

Both give you different levels of control for outputting elements to be composited.

#310

Hi,

Fran, Is this currently possible? would you be able to add mental ray lighting to the bufferstore or ctrl_shader?

thanks for your work,

matt

#311

Linux? I feel like the dirty outcast that everyone shuns. But I gotta keep asking for a Linux compile cause it would be nice to use this in production.

#312

I second the dirty outcast.

#313

How 'bout OS X? Pretty please.

#314

Francesca,

First of all thanks very much for contributing this shader to the Maya community. You are awesome!

I would like to report on a few bugs I am experiencing to help you with the development of the shader.

On my system, currently I cannot use exr as an option for the output of framebuffers, when I do so, it coughs up an error about .exr not supporting that feature yet and hangs maya indefinitely. Maybe someone else can confirm this bug on their system.

It would be cool if that issue could be fixed and the buffers could be written directly to exr. Currently to get good floating point output I have to render floating point iffs then convert those using imf_copy to floating point tiffs or something else that my compositing program will recognize.

Also, when I have the coverage buffer enabled either in the Buffer_API and/or in the Buffer_Write shaders, it produces an alpha file that has some noise and artifacts in it. When I turn the coverage buffer off in both shaders it produces a good alpha. I can see this problem even in the scenes you provide in the version 1.5 release of this shader when I simply open the file up as given and click render. The artifacts in the alpha are subtle but there so if anyone wants to confirm the bug make sure to look closely. Anyway, there is enough of an artifact there to make compositing with this shader with the coverage buffer enabled problematic.

Anyway, just reporting on some bugs I have found. This shader is awesome and opens up doors for the Mental Ray and Maya community. So again thanks and you rock.

cheers,
Cory Redmond

#315

hey folks. i have just registered, because i read on cgarchitect from this ctrl_buffer-thread and the thing, that might solve my problems with specific render-passes from mental-ray. but as i read on in here and tried this little thing by myself ā€¦ i am absolutely not able to see some logic in that means: i cannot use this thing to get it work for me :frowning:

my goal is to get an extra refraction pass out of my dielectric within a scene so that i can compose that on at a later time. but these framebuffers donā€™t popup and i have no idea how to set that all up. i looked at the provided scene-files but they are totally incomprehensible for me too :frowning: i have not read all of this thread (iā€™m a german and itā€™s quiete hard to get it all translated gg) so sorry if this was discussed already at a earlier stage. well: could you give me an roundup for the main-usage of these plugins and thankfully with an example of the refraction pass, that i want to get ?? this would be very very great !!!

thx in advance
s2k

#316

I really like this shader, Iā€™m wondering about miā€™s framebuffer logic tho.

I understand that it is faster to filter the primary buffer but isnā€™t this killing the rendertime to output a frame that is comped in camera? Arenā€™t buffers/channels/passes supposed to save rendertime at times when you donā€™t want to do that?

Iā€™m uncovering these issues with a scene where Iā€™m trying to raytrace into an object and get interior reflections. I can get them only with a primary buffer and the reflection pass (Iā€™m using mib_reflect) has the correct alpha but isnā€™t tracing into the object, yet the color sampling is acting like it is, as if I rendered the frames in camera.

#317

Hi everybody,

i am playing with this incredible shader and ran into a problem that looks like thatā€¦

Any idea?

additionally iā€™m still not sure how to sample those passes? any advice would be really apreciated!

thanx

#318

You need to read the pages before more carefully. Then you would see that for passes to get enough samples you need to up your min samples to say 1 or 2 if needed. Thatā€™s the main drawback but many can live with that.

As for clipping of your front object there can be number of issuses. First check your camera clipping planes and dont auto anything. Second it can be a Bug in Maya 7. God and Alias know that theres so much more bugs in 7 than all the previous versions combined.

Thrd try to move your camera for like 0.01 or less and rerender. Sometimes that clears the problem on error frame.

I hope some of it helps.
:slight_smile:

#319

Note that what actually gest written into the tag buffer is simply the state->label of the top level ray.

Hence you donā€™t need to make a scene-traversal tool to write per-object tags, you can write a simple lens shader that does something like

state->label = state->instance

or somesuch.

/Z

#320

sure zap. but at that point I will haveā€¦

  • a geoshader to enable buffers
  • a buffer write to write in the buffer
  • a lens shader to get the label
  • an output shader to write out the img

I preferred to get the thing from a geoshader as it was
already needed. I will remove probably also the output
shader to get the whole from the geo one.

ciao
francesca