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Render Outputs


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modo offers many different 'Render Output' types useful in a variety of situations ranging from purely diagnostic, to specific compositing utility in an external application. A default scene automatically includes a 'Final Color' and 'Alpha' output which should be fine for most situations. Additional layers can be added by using the menu bar command "Texture > Add Shader Tree Layer > Render Output", or from within the shader tree viewport itself, by LMB-clicking the 'Add Layer' option of the full viewport window and selecting 'Render Output' from the pop-up context menu. This adds an additional layer to the top of the tree. Users may then RMB-click in the 'Effect' column of the shader tree for a pop-up context menu that allows one to select alternate output types. All enabled outputs are rendered simultaneously each time the 'Render' or 'Render Animation' commands are invoked. Once rendered, the individual outputs appear in the Render Display viewport accessible from the layer menu. Please reference the primary Render Outputs page of the documentation listed under the Shader Tree Layers section for for information regarding the editable attributes of the individual outputs. The various output types available are as follows--

Depth
Depth Output
The 'Depth' output generates a Z-Buffer that represents the distance from the camera to the geometric surface in shades of gray. Rays begin white at the ray origin (camera position) and attenuate darker as they get longer becoming fully black at the specified 'Maximum Depth' value. Useful for calculating Depth of Field in an external application or for composing a fog effect into a rendered scene.

dPdu Vector
Dpdu Vector
The 'dPdu' and 'dPdv' are world space vectors that point in the direction of increasing U and increasing V at each point on a surface that has a UV map. dPdu and dPdv have a big effect on the anti-aliasing of UV image maps and also define the reference directions for anisotropic highlights and reflections, so the outputs are sometimes useful for the purposes of debugging.

Dpdv Vector
Dpdv Vector
The 'dPdu' and 'dPdv' are world space vectors that point in the direction of increasing U and increasing V at each point on a surface that has a UV map. dPdu and dPdv have a big effect on the antialiasing of UV image maps and also define the reference directions for anisotropic highlights and reflections, so the outputs are sometimes useful for the purposes of debugging.

Geometric Normal
Geometric Normal
The 'Geometric Normal' output simply renders all meshes with a color ramp based on the angle of their polygonal normal. It is useful for evaluating the continuity of a mesh's surface. In this example smoothing has been disabled.

Segment ID
SegmentID
When modo renders a project, all meshes are broken down into "segments" for reasons of optimization and general scene management. Using the Segment ID shading option will render each generated segment with a random color. This shading method is purely a diagnostic option.

Surface ID
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The Surface ID output render each material with a random color. This is purely a diagnostic shading option, as it may be helpful in spotting surface relationships in complex scenes.

UV Coordinates
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The 'UV Coordinates' output generates a channel that converts UV positions to a color value. Some software is then capable of utilizing this image to reapply a texture map to the object after it has been rendered.

IC Positions
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The settings within the 'Render Item > Properties > Global Illumination' tab allow you to specify values that the Irradiance Cache uses to shade a rendered scene. The 'IC Positions' output will display the pixel positions used in generating the shading based on the Irradiance Cache values. Green points are positions sampled during the initial pass, Red points signify additional sample generated by the Interpolation Values setting. Useful in analyzing various IC settings.

IC Values
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The settings within the Render Item > Properties > Global Illumination Tab allow you to specify values that the Irradiance Cache uses to shade a rendered scene. The 'IC Values' output will display the diffuse values calculated during the initial irradiance cache render pass. The image will appear splotchy as each irradiance sample is not blended with nearby samples; giving one a much better understanding of the area affected by individual IC positions. Useful in analyzing various IC settings.

Diffuse Coefficient
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The 'Diffuse Coefficient' output renders the diffuse colors of a scene independent of illumination or shading.

Reflection Coefficient
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The 'Reflection Coefficient' output renders a scene as grayscale image that represents the reflection amount per surface. Black for 0% reflectivity ramping toward white at 100%.

Specular Coefficient

The 'Specular Coefficient' output renders a grayscale image that represents the amount of specular on surfaces within a scene. Black for 0% specularity ramping toward white at 100%.

Ambient Occlusion
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The 'Ambient Occlusion' output generates an occlusion map where occluded areas; crevices and other inaccessible areas of a scene shade darker, while open areas render lighter colors, approximating an overall global illumination type of shading. Grainy renders can be smoothed out by increasing the 'Occlusion Rays' value, controlling the density of the occluded areas is done through the 'Occlusion Range'. Reference the 'Ambient Occlusion' section on the alternate Render Output page for more information.

Reflection Occlusion
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The 'Reflection Occlusion' output renders a channel that is strictly black and white, determining if a reflection ray off of an object has hit any other geometry in the scene. White if it has and black if it has not. The areas that appear as white here would be shaded with the background environment in a Final Color render.

Alpha
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The 'Alpha' output will calculate the opacity of the objects based on their material settings to determine an alpha (transparency) value. With this setting, environment colors and textures will not contribute to the alpha channel, so that when you view the final image with an application that supports alpha channels, only the rendered geometry will be visible. If an object or surface has a level of transparency this will also be considered in the alpha channel. In this way it is possible to render out images with semi-transparent elements that can easily be composited over other backdrops in an application such as Shake, Motion or Photoshop. For best results when compositing multiple images, you should enable 'Unpremultiply Colors' in the corresponding 'Final Color' output.

Final Color
Final Color
The 'Final Color' output represents the settings of the shader tree, leveraging all visible material and texture layers as well as shaders and the render item settings.

Diffuse Shading (Direct)
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The 'Diffuse Shading (Direct)' output renders a channel of the diffuse color and shading of all objects in scene by all direct light sources independent of other surfacing attribute. Basically a combination of diffuse coefficient and direct illumination.

Diffuse Shading (Indirect)
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The 'Diffuse Shading (Indirect)' output renders a channel of the diffuse shading of all objects in scene by all indirect light sources independent of other surfacing attribute. Basically a combination of diffuse coefficient and indirect illumination.

Diffuse Shading (Unshadowed)
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The 'Diffuse Shading (Unshadowed)' output renders a channel of the diffuse color and shading of all objects in a scene by all light sources, independent of other surfacing attribute while excluding shadows cast by direct and indirect lights sources.

Diffuse Shading (Total)
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The 'Diffuse Shading (Total)' output renders a channel of the diffuse color and shading of all objects in a scene by all light sources, independent of other surfacing attribute.

Illumination (Total)
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The 'Illumination (Total)' output generates a channel of the full illumination in a scene including shadows cast by direct sources, independent of all other surfacing attributes.

Illumination (Direct)
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The 'Illumination (Direct)' output generates a channel exclusive to the illumination in a scene from all direct light items such as distant lights, area lights, point lights and spot lights, independent of all other surfacing attributes.

Illumination (Indirect)
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The 'Illumination (Indirect)' output generates a channel exclusive to the illumination in a scene from all indirect sources such as image based lighting and luminous polygons, independent of all other surfacing attributes.

Illumination (Unshadowed)
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The 'Illumination (Unshadowed)' output generates a channel of the full illumination in a scene excluding shadows cast by direct sources, independent of all other surfacing attributes.

Luminous Shading
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The 'Luminous Shading' output generates a channel of all the luminous shading within a scene independent of all other attributes.

Motion Vector
Motion Vector
The 'Motion Vector' output encodes the direction and speed of each pixel into an RGB value, which can then be further processed in an external application to apply motion blur to a rendered image as a post production effect. This can greatly enhance the smoothness of motion blur and save rendering time when processed this way, however, since each pixel can only have a single color value (and therefore a single motion vector), incorrect result will be produced when motion blurring transparent or translucent objects moving in a scene.

Shading Normal
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The 'Shading Normal' output renders all meshes with a color ramp based on the angle of their surfaces shaded normal. Where the geometric normal is calculated exclusively by the polygonal geometry, the shading normal also takes in to account surfacing attributes affect on normals such as bump maps.

Reflection Shading
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The 'Reflection Shading' output generates a channel of all the reflection calculated within a scene independent of all other attributes.

Specular Shading
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The 'Specular Shading' output generates a channel of all the specular shading within a scene independent of all other attributes.

Subsurface Shading
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The 'Subsurface Shading' output generates a channel of all the subsurface scattering shading within a scene independent of all other attributes.

Transparent Shading
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The 'Transparent Shading' output generates a channel of all the Transparent shading within a scene independent of all other attributes.

Shadow Density
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The 'Shadow Density' rendering output renders a channel generated from the density of all direct light shadows in modo exclusive of color shading or texture. The darkest areas of shadow render as white white ramping toward black for the areas that would be fully illuminated. When rendering in layers, it is very useful to have shadows rendered separately giving one control of color and transparency. You could easily invert this channel in an image editing application and layer it over the unshadowed render set to 'multiply', giving control over how dark the shadows are based on the layers transparency.

Compositing Outputs

Render output are incredibly useful when users wish to compose the generated layers individually in an external application, such as Photoshop, After Effects, Nuke or Fusion. This can aide in tweaking color, among other settings as a post process without requiring additional render time. The question most often asked is "Which Render Outputs combine to equal the Final Color output?" The answer is "Diffuse Shading (Total) + Transparent Shading + Reflection Shading + Specular Shading + Subsurface Shading + Luminous Shading = Final Color", where each successive layer is added to the layer below in the composition (also called Linear Dodge). Users may also render out simultaneous alpha channels for each item in a scene by creating item masks for each and placing a render output set to "effect:alpha". Then each time a render command is invoked, all active (visible) render outputs will be generated simultaneously.

Render Outputs COmp

 

comment balloon Comments (10) RSS Icon

MrWyatt December 21, 2010 at 8:11 AM

Motion Vector Output introduces visible offset of the moving objects, that shouldn't be there. Every object should be in the rendered image at the same spot where it would be with motion blur or motion vectors deactivated. I think this is a bug.

3deric December 22, 2010 at 2:15 PM

MrWyatt, you could be correct... However, if the object in motion is placed anywhere along the correct motion path of it's animation, the Motion Vector Output values could be describing a blur that 'smears' the object's apparent position back along the correct path too. Have you done any tests?

I've been trying to get it to work correctly, but I've run in to the problem that the Motion Vector output seems to only return green pixel values for me.

MrWyatt December 30, 2010 at 4:15 AM

I don't have to try anything to see this is a bug as other applications who had the ability to output reelsmart motion vectors for years, don't do this. Now modo has this functionallity and introduces something noone else has done before? Sounds kinda silly to me. This is clearly a bug and I want it fixed.

MutantPixel January 28, 2011 at 9:14 AM

There is an error in the 'Composing Outputs' section - Where it says 'Illumination Total' it *should* say "Diffuse Shading (Total)", otherwise the layers wont combine to produce the same result as the 'Final Color'. This will be fixed in the next update.

Ultradigital March 15, 2011 at 12:40 PM

This information should be add:
When using the gamma 2.2 workflow, every render output must be rendered in gamma 1.0 and Clamp colors turned off. Then a gamma 2.2 curve must be applied in the compositing package!

MutantPixel March 15, 2011 at 3:36 PM

Good point Ultradigital, I'll see about adding that. Thanks.

Ultradigital March 18, 2011 at 4:13 AM

By the way, Dithering must be turned off too!
We can also use a 2.2 gamma when rendering all the different Render Outputs ans still get results as expected. This depends of your composting software.
In AE, there's an option (Project Settings)that allows to internally makes all the image calculations in gamma 1.0 and give the results at the 2.2 gamma from the imported footage.

Ultradigital March 18, 2011 at 4:07 AM

One other thing that must be stated, is that since the different Render Outputs relies on the Final Color output antialiasing settings, this Render Output must always be turned ON or else you'll get aliased results on all the other Render outputs.

Arisbay November 28, 2011 at 2:46 AM

Hi,
Could you please direct me to a document or give me instructions on how to render only the lines so the generated image looks like a 2d Illustration
Thanks a lot
:-)

3dtodd January 23, 2012 at 6:06 PM

How about a simple Diffuse pass without the shadows? This is a strange set of choices, when a simple straight forward Diffuse pass isn't even available.

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