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RENDERING
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DESIGNER S
V-Ray for SketchUp
By Chia Fu Chiang Damien Alomar Jorge Barrero
Table of Contents
Install V-Ray for SketchUp................................................................ Activating V-Ray for SketchUp........................................................... Before you Start Rendering............................................................... Understanding Default Settings.......................................................... Render Options............................................................................ Save and Load Option Settings Two ways to assign materials in V-Ray Material Editor............................................................................. Diffuse Layer Adding a new Material How to duplicate a material How to change the name of a material How to remove a material Others Material Usage............................................................................. Add Lights.................................................................................. The Characteristics of Rectangular Light............................................... Size does matter Shadows change according to the size Impact on reflective objects due to visible and invisible rectangle light Double Sided Option Material: Reflection Layer................................................................ Adding Reflection Layer Fresnel Reflections Reflections and Highlights................................................................ Other Parameters.......................................................................... Reflection Glossiness Reflection Filter Refraction Layer........................................................................... Add Refraction Layer Controlling the Amount of Transparency The color of refractive materials Fog Settings Explained Adjusting Refraction IOR The Glossiness of Refractive Materials Shadows of Refractive Materials Double-Sided Material Translucent Material Emissive Materials......................................................................... Add Emissive Layer Adjust the Intensity Adjust the Color Emissive Textures Texture Mapping........................................................................... Projection Types and Adjustments Bump Maps................................................................................. Displacement.............................................................................. Adding Displacement Displacement Parameters Adjusting Displacement 6 7 8 9 10
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Transparency Mapping.................................................................... What is Transparency Mapping How Transparency Mapping Works Another Method to create the same result Other uses for transparency mapping V-Ray Linked Material..................................................................... V-Ray Two-Sided Material................................................................. Adding a V-Ray Two-Sided Material Working with V-Ray Two-Sided Material V-Ray for Sketch Up Two-Sided Material................................................. Adding a V-Ray for Sketch Up Two-Sided Material Working with V-Ray for Sketch Up Two-Sided Material Environment Lighting..................................................................... Interior or Exterior? Techniques for adjusting illumination HDR Environment Light Source Bitmap Environment Light Source Environment Light source for semi-open space Choosing different Render Engines...................................................... Classification of Light Bounces Primary Engine: Irradiance Map Primary/Secondary Engine: Quasi Monte Carlo Secondary Engine: Light Cache Lighting Dialog Box........................................................................ Light and Shadow.......................................................................... The Quality of Shadow Radius for Shadow edge Depth of Field.............................................................................. What is Depth of Field? How to find out the focal distance Size of Aperture Change focal distance Physical Camera........................................................................... Type of Camera Exposure Adjusting Exposure Using Aperture Using Shutterspeed Using ISO Adjusting White Balance Sun and Sky................................................................................. Using the Sun with the V-Ray Physical Camera Accessing the Sun Properties Exposing Your scene with the Physical Camera Adding the V-Ray Sky Time of Day and the Sun's appearance Changing the Sun's Appearance with Turbidity Changing the Sun's Appearance with Ozone Gamma Correction and the V-Ray Sun and Sky Enabling Gamma Correction Using Color Mapping with the V-Ray Sun Caustics.................................................................................... What are Caustics? Examples
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Color Mapping.............................................................................. The Function of Color Mapping Types of Color Mapping Adaptive Subdivision Control............................................................. Adaptive Subdivision Sampler Fixed Rate Sampler Adaptive QMC Sampler Resolution of the Image................................................................... Image size setting Saving your image V-Ray Frame Buffer........................................................................ Render image window toolbar Distributed Rendering..................................................................... Setting Up the V-Ray Distributed Rendering Spawner Finding the IP address of the slave Computer Starting the DR Spawner Connecting to Slave Machines Some Considerations for Distributed Rendering Sample Materials..........................................................................
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Installing V-Ray for SketchUp
1. Make sure that SketchUp is closed and begin the installation process. 2. License Agreement, click next to continue.
3. Choose complete setup type, click next to continue
4. Choose destination location, click next to continue
5. Installing
6. Installation complete.
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V-Ray for SketchUp
Activating V-Ray for SketchUp
1. After finishing the installation, run the Sk etchUp program.The We lcome page should come up automatically. V-Ray for SketchUp installs under the plugins folder by default. 2. The InstallShield Wizard will ask you to select one of the options. If you haven't purchased V-Ray for SketchUp, you can choose “I want to evaluate V-Ray for SketchUp, but I do not want to activate at this time.
3. If you already have a serial number, you can select the other option, “I have a serial number and I want to activate V-Ray for SketchUp. Then click next.
4. Enter your serial number then click next. It will start activating.
5.Activating usually takes several seconds to finish. After activation is complete you will not need to activate it again when you start V-Ray for SketchUp.
V-Ray for Rhino只
能限制給一台電腦啟動。
V-Ray for SketchUp
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Before you start rendering with V-Ray for SketchUp
When rendering an image with any rendering program, including V-Ray for SketchUp, you must understand three main factors that will affect the image: Lighting, Materials, and Mapping. Lighting plays the most important role among these three. It will affect the color, shadow, reflection and refraction among every single object in the scene. V-Ray for SketchUp is a rendering engine equipped with Global Illumination (GI), which helps the users setup the lighting for entire scene easily. So they don't have to spend a lot of time adjusting lighting location and brightness. The concept of GI is very simple. Imagine a room has a window but no light in it. The natural light from the outside of the room comes in through the window so the room doesn't look completely dark even though there is no light in it. Some people even call this the “lazy boy lighting”. Its purpose is allowing the users to have the most natural light possible without spending too much time to achieve it. V-Ray for SketchUp also supports High Dynamic Range values, also called HDRI (High Dynamic Range Image). With a normal 24bit, 8bit per channel RGB image (Low Dynamic Range Image), the brightest white color you can get is R255, G255 and B255. But this is still thousands times lower than what the sun light can produce. With the HDR file format, users can have more control ranging from dark to bright. The HDR is a very special image file format. It usually starts with professional 360 degree photography, then transforms to 96bit full scene image by using professional HDR software. The benefit of using HDR is that you can use this full scene image as your render light source. It also can be used as the back ground rendering. V-Ray for SketchUp also supports regular image file formats as light source for GI. However, it is still limited when using HDR image format to describe the lighting environment. Together with other regular image file format simulated lighting environments, it usually being used only as supporting lighting for the entire scene. That means adjusting the setting of major light sources is still a very important work in V-Ray for SketchUp. We will discuss more about how to use lighting, materials and mapping later.
(above HDR and renderings are supported by Dosch Design ) http://www.doschdesign.com
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Understanding V-Ray for SketchUp’s Default Settings
Rendering with the Default Settings The Default Options in V-Ray for SketchUp are set up so that certain elements of V-Ray are already enabled. This is good because certain aspects that are specific to V-Ray are already configured with a proper setting. However there are a number of elements which are contributing to the final render, and it is important to know what they are so that unwanted results are avoided when we start adjusting the render options ourselves.
Key Elements in the Default Settings There are three main elements specific to V-Ray that are creating some of the aspects of the default render. These elements are Indirect Illumination, the V-Ray Sun and Sky, and the V-Ray Physical Camera. These elements will be explained very briefly here, and you can reference other chapters in the book for a detailed explanation of these elements. Indirect Illumination is simply light that does not come directly from a single light source. In V-Ray this typically references two types of light; Global Illumination and Bounced light. Global Illumination is simply a dome of light that is emitted around the scene, and this can make setting up lighting very quick and easy. Bounced light is simply the light energy that is bounced from a surface. This bounced light is what allows V-Ray to create high-quality renderings. explanation of Indirect Illumination please refer to page 66. The V-Ray Sun and Sky is physically accurate lighting model allowing for easy recreation of the effects of the Sun and Sky. This is an excellent tool for setting up exterior renderings with a sun. Due to the nature of the model in which the sun and sky are based off of, you will find that under standard conditions the sun and sky will be extremely bright. Because of this the V-Ray Physical Camera is used to expose the scene and brings the rendered image to a desirable level. The V-Ray Physical Camera is modeled after a real-world camera and can be used to expose a scene. In the real world, lighting is different in many situations, and because of this a photographer will use the capabilities of the camera to properly expose the image. Proper exposure means that the image is not overly bright or too dark. When creating renderings this gives us the opportunity to set our lighting as it would be in the real world (in this case it is the Sun and Sky) and adjust our camera settings until we achieve the desired result. The detailed explanations of the Sun and Sky and the physical camera are on page 79 and 82. For a more in depth
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Render Options for V-Ray for SketchUp
Open V-Ray for SketchUp - Render Options The V-Ray for SketchUp Options controls all rendering parameters. You can open this Render Options from Plugins menu above or click directly on the VRay Options.
Save and Load Option settings There are many Options settings in V-Ray for SketchUp. Users can save the current settings, or save different files according to different scenes, different render quality settings, or different render engines. From File>Save to save Options setting. Use .visopt as the file format. It's about 2KB in file size. When the SketchUp file is saved, all changes in V-Ray Options setting will also be saved. Use File>Load to load saved .visopt Options files. It will replace the current settings. Use Restore Defaults to restore the original V-Ray settings.
Open file Chairs-Original.skp. There are 3 chairs and a very large floor in the file. All objects are not assigned to any material and there is no light in the scene as well. Please click the blue render icon from above directly and you will get this gray tone image without changing any setting in the V-Ray Options.
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V-Ray for SketchUp
Open V-Ray Options window and pull down the Global Switches, Environment and Indirect Illumination taps as illustrated below.
1. Global Switches Please uncheck Hidden Lights and Default Lights under the Lighting section. Hidden Lights means hiding the lights from the scene.
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It is used when the users don't want to see any light while modeling in the scene. When uncheck the Hidden Lights box, those hidden lights will not affect the V-Ray render. To prevent these hidden lights affect the final render output, we recommend you uncheck the Hidden Lights first. Default Lights means V-Ray built-in lights. Users can
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not see nor edit these lights from the scene. If one uncheck the Default Lights and does not check the GI below, the render will turn out totally black. We also recommend you check the Low thread priority under the Render section so that it won't
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affect other program while rendering with V-Ray. 2. Indirect Illumination Please check the On under the GI section. That turns the Indirect Illumination on, so called the Global Illumination. We will explain those green dot items more later. 3. Environment Environment is to control the contract, color, and HDR of the Global Illumination. Please check the boxes before GI and Background. Please adjust those three items then select the blue render icon on the top. You will get the image with Global Illumination. Compare to the image without Global Illumination, you can see the objects don't have dark shadow because the objects get light from all around.
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The image is in blue tone is because the default environment color of V-Ray is set in light blue of R204, G224, B225. Please check the box under GI to enter the color selections. Change the Sat from 62 to 5. The color is changed to light blue of R250, G252, B255, which is very close to white. Click OK to exist then click on the blue render icon to color the image. The image color becomes very close to white like the image on the right.
Because the chairs and floor are not assigned to any materials, V-Ray gives the objects SketchUp’s default white layer as material. To know how to assign the materials to the objects and make adjustments, we need to open the Properties tab.
Two ways to assign materials in V-Ray 1 . Press Ctrl+A to select all the objects in the scene then righ-click the objects, select V-Ray
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2. In the material window, select Default_VRay_Material, then click apply.
3. Now the objects are applied with materials. You can open the Material Editor to edit and create materials.
Another way to assign materials is through the material editor. Please refer to page 15
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Material Editor in V-Ray for SketchUp
Material editor can be pulled out from the icon under VRay for SketchUp tool box, from Material Editor from Plugins V-Ray tab, or by right-clicking the Edit button in Properties window.
V-Ray Material Editor V-Ray for SketchUp's Material Editor has three parts: A . Material Workplace shows all the selected materials. Right click to add, import, export, rename, remove, and select the objects with current materials, such as assigning current materials to the selected objects, deleting materials that are not used in the scene, and adding layers with reflections, refractions to the materials. B . Material Preview, the Update Preview button allows you to preview the adjusted materials. C . Options for material control. The options change with the added scene materials in section A.
B C A
Click on Update preview button to update the preview image to current materials.
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Diffuse Layer Color: used to apply color on material. The m box on the right is used to apply pattern and arrange sequence. Transparency: used to adjust the color transparency. Black is completely opaque and white is completely transparent.
How to add new material:
1 . Right click on Scene Material, select Add new material, Add VRayMtl. 2 . Right click on Scene Material, select Import new material to import a saved material file. 3 . Right click on object, click on Create button to add a new material.
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How to duplicate a material:
Under Material Workplace, right click on the material you wish to duplicate, and select Duplicate. This is another way to add a new material.
How to change the name of a material:
Right click on the name of the material you wish to change, and select Rename. The name of the material can not have a number in the first digit or spaces within the name
How to remove material:
Right click on the name of the material you wish to delete, and select remove. If the material being removed is applied to the objects in the scene, V-Ray will show a pop-up window to ask if you want to remove it for sure.
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V-Ray for SketchUp
Others
Right click on the material you wish to export, and select “export” to export this material. The file extension is .vismat, the file is 1 KB. This file can be imported or sent to other users later on.
Another three selections:
1 . Select Objects by materials: Selects the objects in the scene with this material. 2 . Apply materials to object(s): Applies this material to selected objects in the scene.
Any materials under the Scene Materials can be applied to objects by right-clicking on the model object.
Purge unused materials: Right click on Scene Materials to select purge unused materials to remove materials which are not applied on the scene objects.
You can not use undo to undo the change in Material Editor.
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Material Usage
01 . Open Chairs-GI.skp file. Select all the objects. Right-click over the model, select Vray for SketchUp, and click Create to add a new material. Material Editor will show a new material named DefaultMaterial under Scene Material. 02 . Rename this new material as Ground. The file sets V-Ray Options to GI and has GI environment light and background color. Hidden Lights and Default Lights are closed. Other options remain default.
03 . Select Diffuse to enter color selections .V-Ray's default color is R-128, G128, B128. Change the color to light gray as: R230, G230, B230 then exit 04 . Right click on Ground material. Select Duplicate and rename as Chair-Orange. 05 . Left click on the empty spot to deselect the objects. Go to Top view and select these cups from top left to bottom right. Then go back to Material Editor and right click on Chair_Orange and select Apply material to objects
V-R ay auto mati ca lly update s th e ch ange s of mate ri als to th e objec ts . It is not nece ssary to apply mate ri als aga in.
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V-Ray for SketchUp..."
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