Autodesk Combustion 4 Integration with 3ds Max and Autodesk VIZ

Transcription

1 12/1/2005-8:00 am - 11:30 am Room:Peacock 2 (Swan) Walt Disney World Swan and Dolphin Resort Orlando, Florida Autodesk Combustion 4 Integration with 3ds Max and Autodesk VIZ Gary Davis - visualz, LLC DV41-2 This session will focus on how to integrate and work with output from 3ds Max and Autodesk VIZ within Autodesk Combustion 4 software. We will showcase the Rich Pixel Format (RPF) and render output elements from Max and VIZ to show how to manipulate them in Combustion 4. This class is for existing users of Max and VIZ who want to add Combustion compositing to their workflow. We'll explore the basis of these concepts and techniques using an existing 3D scene. About the Speaker: Gary received a BFA in computer animation 13 years ago. In that time, he has been heavily involved with computer animation and simulation for the fields of architecture, ride-films, broadcast design, visual effects and the Internet. His production client list includes ABC, MTV, FOX, Sci-Fi Channel, Disney, Universal, and Lockheed, among numerous others. In addition to his production work, Davis is currently one of only three worldwide, certified Discreet training specialists for 3ds Max and Autodesk Combustion. He has written for several industry publications and is the author of The Focal Easy Guide to Discreet Combustion 3. Now specializing in the integration of 3D and compositing applications, he continues to train and consult with his company, visualz, LLC. garyd@visualz.com

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3 Working with Render Passes Render Passes is not a formal term within 3ds Max or Combustion. This is a term often used to differentiate this with the topic of Render Elements (below). In practice, people often do render passes as render elements but let s not get ahead of ourselves. Render passes is simply a way to break your scene into different render jobs. This is often done for various reasons, but some common reasons are: To save time. If you have a locked off camera that is not moving, this means you can render only one background and then separate the moving objects/characters in your scene for animation rendering To save memory. If you have a scene that simply takes up too much memory to render all at one time, you can try to split it up based upon depth (basic setup of foreground, mid-ground and background). Flexibility. Say in 3ds Max one loads SKY01.JPG as a background and renders over it without passes. If the user later decides to change the sky, it would typically require a re-render. By rendering in passes, one can easily re-render the sky alone and then quickly composite the new image sequence in Combustion. Since this is just a sky render, the job will take minutes instead of hours or days. By approaching your job in this way, you can, for example, easily render multiple sky backgrounds and then decide later which is the one you (or the client) like best. Breaking up your scene in passes also accommodates selective effects like color correction or blurs for simple, faux depth-of-field effects. Two very common ways in 3ds Max to accommodate the rendering of passes Selection Sets and Layers. Either of these ways of working are good organizational methods. It should be noted, however, that while an object can only reside on one layer, any object can be in any number of selections sets. While many AutoCAD users are used to and use the layer system for many purposes, this consideration should be taken into account when planning your render passes. One nice feature of the layer system, however, is that they can easily have their render-ability turned on and off with a single click. Different stroked for different folks, as it were. In practice, when one is ready to render a pass, those objects can be selected and then everything else can be temporarily hidden using the hide and unhide commands found in the Display panel. The job gets submitted for rendering and then the user can unhide everything to continue working. 2

4 Working with Render Elements In a nutshell, render elements is the process of breaking down your final rendered image into more than one image sequence. By separating different channels of the image and also outputting additional channels, applications such as Combustion can use this data for post-processing effects that might be too time-consuming or even impossible to do in the 3d renderer. Common example is selective color correction, depth of field, motion blur, and specular blooms. This is fundamentally different than render passes in that regardless of what is getting rendered (the whole scene, just the foreground, etc), the components of the rendered image are still broken down into individual, user-defined elements. It is, therefore, certainly possible to render passes AS render elements. For example, Three render passes with different options for elements: Foreground specular, diffuse, shadow, velocity, Z depth, and three mattes. Trees specular, diffuse and shadow elements. Sky (background) main image only. No elements. In this example, three different render tasks are created and rendered. The first two break down the pass as elements. Within Combustion, everything gets assembled as a single composite, thus offering a tremendous amount of flexibility for post processing that would take much longer to do in 3D (and require a re-render from MAX). The most important thing to remember when rendering images with elements is that you must render to a file format that supports an alpha channel. JPG files will not work, for example. I recommend using PNG or EXR as they can contain an alpha channel, can be higher color than simple 8 bits per pixel, and use lossless compression algorithms. The screen grab below is from 3ds Max 8. There are currently 21 different render elements available for output. One important aspect of render elements to understand is that they are not all meant to be visible in the final composite. Several of the elements available for output can be considered utility elements. That is, they will not be seen in the final image. These are typically used by Combustion to limit an effect to specific areas of the image. Non-visible elements include Alpha, HDR data, Material/Object IDs, Mattes, Velocity and Z Depth. 3

5 Below is a brief description of each render element. Alpha This is a grayscale image that separates all rendering portions of the MAX scene from the background. Atmosphere All effects found in the Rendering > Environment dialog will be included. Two useful functions possible are to render your atmospheric effects too thick and largely neutral in color. Then in Combustion you can reduce the opacity and also color tint the effects with a Color corrector. Note that both of these solutions affect all atmospherics at the same time, however. Background If a background is loaded, it will be put in this element. However, it is highly recommended NOT to use a background when rendering out of 3ds Max. Keyframing and setting up cameras with a background loaded is fine, but don t render over the background if you plan on doing any compositing. This is because the rendering items in the MAX scene will be antialiased to this background. If you wish to replace the background later in post, then you will not be able to unpremultiply and/or antialias to this new background. By turning off the background before rendering, you can add any background later in Combustion. Blend This allows you a combination of several different elements. The Blend element is very much a case-bycase solution for different circumstances. When all options are enabled, it results in the same as the full render, except for the background is not present. Diffuse This is the main color component of your image. You can optionally include the lighting information in this render element. Hair and Fur Items created with the Hair and Fur modifier Illuminace HDR Data - Generates an image containing 32 bit floating-point data that can be used for analyzing the amount of light that falls on a surface perpendicular to its normal. The illuminance data ignores material characteristics such as reflectance and transmittance. For best results, render with mental ray or another renderer that supports 32 bit floating-point output and set the output format to PIC, HDR, or EXR. Ink The lines of an Ink and Paint shader 4

6 Lighting The can be and of direct, indirect and shadows as they relate to the lighting. For maximum flexibility, render three lighting elements; one of each. Luminance HDR Data Generates an image containing 32 bit floating-point data that can be used for analyzing the perceived brightness of a surface after light has been absorbed by the material of the surface. The luminance data considers material characteristics such as reflectance and transmittance. For best results, render with mental ray or another renderer that supports 32 bit floating-point output and set the output format to PIC, HDR, or EXR. Material ID Any material IDs set in the material editor will be utilized here. There are only 16 material IDs available in a scene, but a powerful feature of these is they can be part of a sub-object material. Matte My personal favorite. This allows you to create a black and white image of one or more objects in your scene. These can be created by Object ID, Material ID, object name or selection sets. The Matte Render Element can be used as a secondary input to many operators including Compound Channel Selection. Multiple Mattes can be utilized and do not need to be visible layers; therefore, the order in the Workspace Panel is not too important (typically). Object ID Similar to a material ID. Object IDs are, however unlimited in number. These are set in the object properties dialog. Unlike Material IDs, these cannot be sub-object components of a model. You can alternately use the object (wireframe) colors as unique IDs. Paint The main color of an Ink and Paint shader Reflection The reflections in a rendered image. Refraction The refraction in a rendered image. Self-Illumination Any material with a self illumination set higher than 0 will show here. Shadow The shadows in the rendering. This element saves black-and-white shadows only. The mental ray renderer does not include shadows created by global illumination and final gathering in the Shadow render element output. 5

7 Specular The specular highlights of materials. Velocity information of how fast individual pixels are moving in an image. The mental ray renderer supports this element, but the mental ray Motion Blur camera effect must be turned off. Also, some mental ray materials do not support render elements. Z Depth A grayscale representation of the Z depth, or depth within the view, of objects within the scene. The nearest objects appear in white, and the depth of the scene in black. Intermediate objects are in gray, the darker the deeper the object is, within the view. Additional Noted on Render Elements: When you render one or more elements with the scanline renderer, a normal complete rendering is also generated. In fact, the element renderings are generated during the same rendering pass, so rendering elements costs little extra render time. Mental Ray must render the elements individually, but this generally is not much slower than the Scanline renderer doing them all at once. The default scanline renderer supports a maximum of 32 render elements per scene. The mental ray renderer does not limit the number of render elements. If you're using a third-party renderer, check the product documentation for a possible limit on the number of render elements. When using the default scanline renderer, Antialiasing must be on in order to render elements. With Antialiasing off, rendering elements is disabled. In general, you can composite elements using additive composition, which is independent of the compositing order. The main exceptions are the background element, atmospheres, and shadows. o Atmosphere - The atmosphere element should be composited over all other elements. o Background - The background is not trimmed against geometry, the background should be composited under the other elements. o B/W shadows - Black-and-white shadows should be composited over the rest of the image (aside from the atmosphere), to dim color in the shadowed areas. This technique does not take colored lighting into account. o The Diffuse layer is directly above the Background layer. Since the Diffuse layer uses an alpha channel, it is composited using the Normal transfer mode. That is, the Background layer is visible beneath the Diffuse layer. o The Specular layer is composited using the Add transfer mode. The Self-Illumination, Refraction, and Reflection render element layers are also composited using the Add transfer mode, which is independent of the stacking order. For example, if you change the order of the Refraction and Self-Illumination layers in the Workspace panel, the composite is not affected because both layers use the Add transfer mode. o The Shadow layer is composited above the Specular layer to dim color in the shadowed areas. By default, the Shadow layer uses Normal transfer mode because its alpha channel controls how much the black and white shadows dim the Specular and Diffuse layers beneath it in the stacking order. 6

8 o o For the composite to match the 3ds Max scene, the Shadow layer must be below the Reflection, Refraction, and Self-Illumination layers. Otherwise, these three layers would also be dimmed. If the composite has an Atmosphere layer, the layer appears above the Self-Illumination layer. The Atmosphere layer must be composited over all the other layers that are turned on. The Atmosphere layer uses the Normal transfer mode. Working with RPF and RLA images Z Depth Saves the 3D depth of objects in the scene. Material Effects ID Saves the material effects channel ID of materials assigned to objects in the scene. This is called the material ID in the sections that follow. Object ID Saves the ID value assigned to an object. UV Coordinates Saves the UV mapping coordinates used in the scene. Normal Saves the orientation of face normals in the scene. Non-Clamped Color Saves areas in the rendering where colors exceed the valid color range. Coverage Saves anti-aliasing data at the edges of objects in the scene. Node Render ID (RPF format only.) Saves the node ID used when each object is rendered. This is a value unique to each object. In the Combustion interface, this value is called the render node. Color (RPF format only.) Saves the color that the material shader returns. The color is always solid. Transparency (RPF format only.) Saves the transparency that the material shader returns. Velocity (RPF format only.) Saves a vector that indicates the velocity of objects. 7

9 Sub-Pixel Weight (RPF format only.) Saves the weighting value used to adjust this pixel's color. Sub-Pixel Mask (RPF format only.) Saves the weighting value used to adjust this pixel's transparency. 3D Post Operators 8

10 RPF Metadata Information for Post Processing: Channel 3D Depth of Field (Box Blur Type) 3D Depth of Field (Gaussian Blur Type) 3D Fog (blur method) 3D Fog 2 3D Glow 3D Lens Flare G-Buffer Extract RPF Motion Blur Texture Map Z (Depth) R R R R - S - S - Material Effects R3 - R3 - R3 Object R3 - R3 - R3 UV Coordinates R Normal Non-Clamped Color - R1 - S S S Coverage - S S R S S - S S The following channels are not supported by the RLA format. You must render RPF format files to use these channels. Node Render ID R3 - R3 S R3 Color - R1 - R S S Transparency - S - S S4 S - - S4 Velocity R - Sub-Pixel Weight - S - R S5 S - - S5 Sub-Pixel Mask S Table Legend R S Required channel. Suggested channel. 1 Either the Non-Clamped Color channel (which is preferred) or the Color channel must be present. 2 The 3d Fog blur method is used if the Coverage, the Color, or the Weight channel is missing. (The Blur method does not support the "Source Footage"). 3 The Material ID, the Object ID, or the Render ID channel must be present. 4 The Transparency channel is used only if the Weight and Coverage channels are present. 5 The Weight channel is used only if the Coverage channel is present. Keep in mind that the more channels you render, the larger the rendered file but the quality of the effect achieved is the highest possible. Most of the 3D Post effects that use the RPF channels Color, Transparency, and Sub-pixel weight do not require these channels to be present (they are not available for RLA files). If present, the channels are used to improve the quality of the effect. The exception is G-Buffer Extract, which does require the Color channel. 9

11 When you add a 3D Post filter, Combustion notifies you of any missing, required 3ds Max channels. Use the Show G- Buffer filter to examine the G-Buffer channels in an RPF file. Camera Data. One of the least known features of the RPF file format, as it relates to the integration with Combustion, is that in addition to all the extra channels of pixel information, there is also camera data stored in an RPF file. This can be used in a 3D composite within Combustion to match both applications 3d cameras. G-Buffer Builder Autodesk Combustion 4 introduced a new operator called the G-Buffer Builder. This allows you to essentially build an RPF file from render elements, and have all its functionality within Combustion. The only feature missing from a true RPF sequence would be the camera data. Combustion 4 can, as an alternative, get this camera data via the ASE export option from 3ds Max. If you are interested in render elements and also doing depth based composites, this is very much worth the investigation. 3D Paint and Material Editing Anywhere in 3ds Max that you typically might go for a bitmap file such as JPG, TGA, AVI or MOV, you can, instead opt to use a Combustion workspace (*.CWS) file. Vector paint - nondestructive Time from zero and time duration UVW Coordinates Texture channels and nodes in Combustion. More than just texture maps: CC on bitmaps Displacement maps Projectors Environments Painting in 3ds max vs. painting in combustion (and using 2 monitors) Combustion Particles Emitters and deflectors Rendering out tracker plates Some Classic Techniques Depth based Effects Specular Bloom Motion Blur in Post 10

12 Additional, Closing Bullet Points Autodesk Combustion and 3ds Max use the same network rendering management software. Backburner ships with both packages for free and allows one copy of the software to legally render on up to 9,999 machines. For more information, please download my 23-page whitepaper, Down on the Farm, from the training section of my website. Frames and Fields this largely depends on the facility, project, etc. Alpha Channels and Premultiplication always render 3d with alpha regardless. Premultiplication is up to the individuals and projects (but you need to know if you are doing it or not). Frame rate and 3:2 pulldown know your delivery medium. Bit Depths know and understand bit depths for your deliverable. 8,10,12,16, half and full float. Cropping and Auto Crop at the footage level, this can save RAM in Combustion. Color/Broadcast Safe do this in Combustion, not 3ds Max. 11