The Basic Vray Rendering Workflow
|This workflow will showcase the steps necessary to create a basic interior rendering with the Vray for Rhino plug in. The workflow will cover basic camera setup, sun and sky, and materials to create a convincing, high quality rendering.|
|Uses Tool(s)||Rhinoceros for OSX , VRay|
Step 1: Setting up Interior Render View
- Working in Perspective and Parallel Projection views in Rhino you can set up specific scenes that you would like to render.
- Create Infinite Plane
The infinite plane in Vray acts as a ground that reflects light and in the case of exterior renderings acts as a horizon. Add a infinite plane in the defalt layer and make sure it is positioned at the base of your building.
- Setting up the camera
Rendering in Rhino is, in some ways, like taking an actual photograph. There are specific camera settings in both Rhino and Vray that determine lens length, shutter speed, and F-stop. The default lens length in Rhino is 50mm, which is much too long for an interior rendering of a small space. To change the lens length of the Rhino camera go to View -> Viewport Properties ->set Projection to Perspective -> change the camera lens length to 18 mm. There are no set rules for lens length settings. When you are working on your own test different lens lengths to achieve different compositions.
In the Vray Options editor make sure the Physical Camera option is checked. We will adjust the actual camera settings later.
- Saved Views
In Rhino, you can save views so that you'll be able to come back to them at any point later on, even if you've shifted your view around in any of the viewports. Right click on each viewport title and you'll see a drop down menu; go to Set View and click on Named Views. Here you'll be able to save your current view in the currently selected viewport and give it a name.
In the Vray Options editor the default aspect ratio for renderings (both high quality and low) is automatically square, in other words, what you see in your saved render view will not be what you get in an actual rendering. You can change this by clicking “Get Viewport Aspect” in the “Output” settings.
Step 2: Creating a Lighting System
- Lighting plays the most important role in rendering because it affects the color, shadow, reflection, and refraction among objects and materials in the scene. V-Ray comes equipped with Global Illumination : the natural lighting in a scene, a sun and sky , as well as a variety of artificial choose a light that can be added to any scene. For this workflow we will be working exclusively with Global Illumination and adding a Sunlight System.
In the Vray Options editor make sure Indirect Illumination is turned on.
- Add a Sunlight System
To add a Sunlight System click the Vray sun icon. With Manual Control unchecked you can select a specific location, time of year, and time of day for your Sunlight System. We set the time and location to 4:00 pm in San Francisco. Like setting the lens length there are no specific rules for setting up the sunlight systems, depending on the time of day/year/location the sun system will act differently. It just takes some trial and error to find the best lighting for your scene.
Once you click “ok” for the sunlight system a point will appear in your model space, use this to place the Sunlight System. Once you click it will appear as an arrow. It does not matter where you place the arrow; it is just an icon representing the overall system.
There are a few other settings that we want to update in Vray's Options Editor to make sure the lighting and scene is realistic. Under the Environment tab make sure the GI (Skylight) is turned on as well as the Reflection/Refraction (Background). You will then need to click on the "m" icon and add a texture to these settings. Vray has a pre-loaded Sky setting that you can select from the drop down menu. With both GI and Reflection/Refraction turned on the scene will be a bit too bright. Set GI to .5 and Reflection/Refraction to.25. Many of the settings that you will be working with in both interior and exterior renderings are a bit of educated guess and check but this will give you a good start.
This is a good time to do a test render to see how our settings are going.
The lighting/shadows for the image look good but you will notice that the surface is quite blotchy. This usually happens in small dark spaces with bright lights coming in through small wall openings. The problem can be corrected in Vray Options -> DMC sampler -> Global subdivisions. The default setting is 1.0 which is much to low for this type of rendering. Change the setting to 10. This will slow down your renderings a bit so is not necessary when you are first setting up lights but is important for final renderings.
All the light and camera settings are looking good. Now we can start on materials.
Step 3: Adding Materials
- Adding materials to surfaces and forms in Rhino is one of the trickiest parts of rendering, but with a bit of patience an attention you can realistically add materials to your scene.
- Here is a list of sites that have great free textures for rendering
- Ways to add Materials
- Before we get started you should know that there are two ways to add a material with the Material Editor .
1) .vismat – this file type is specific to Vray for Rhino and loads directly into the Material Editor by right clicking on Scene Material and loading that file directly into the Material Editor.
2) other image types – this second method works for many different file types like .jpg, .bitmap, .png, .tiff, etc. However it is a bit more complicated. In the Material Editor right click on Scene Material -> create material -> standard -> click on the “m” under the diffuse tab, next to color -> choose texbitmap from the drop down menu and locate your image file.
- Be sure to re-name your material in the Material Editor. This will make organization much easier down the line.
- Applying Materials to Objects and Layers - Wood Floor
For ease and organization sake I find it easiest to organize my layers so that everything that will be wood is on one layer and everything that will be concrete is on another layer, etc. In the materials editor right click on a material you have loaded and scroll to “add material to layer”. The name of the material will appear in your layers tab. In this case we are adding a wood material to the floor of the building.
Many textures zip files also come with “displacement” and “bump” maps. These are black and white images of the material you are using and add three-dimensionality and texture to the materials making them more realistic. The maps are added in the Material Editor under the Map tab and are uploaded the same way you upload jpg and bitmap files for the base material. For materials like brick, concrete, and wood the default 1.0 value for the Displacement and Bump maps is often much too strong and makes the texture very drastic; .25 is a better value to start with.
- Bump & Displacement Maps: Bump maps do not affect surface normals, displace maps affect surface normals. Bump mapped objects only appear to have depth, but the object's outline does not change. Displace maps change the outline of the object. So, for instance, you'd see the normal or displace maps in the shadow the object casts. Bump maps, you would not. A general rule of thumb is that, if it's an object far away or a simple surface detail, best to stick with bump. If it's stone or an object in close frame, I'd go with displace.
A quick render will show that not only is the scale of the wood way too large but it is also facing in two different directions. Remember for "quick" renders you can reset the DMC sampler back to 1.0 and bring it back to 10 for final renders.
- Scale and Orentation
To fix the material scale and orientation turn off all other layers so only the floor is visible. Select all the floor elements and in the “Properties” tab click “Texture Mapping" and “Apply Planar Mapping”. You will drag a box around the whole area. In this properties box you can also change the scale and offset of the material.
Another quick render will show that our scale and rotation issues are resolved but that the bump and displacement maps are much too strong. Change Bump to .15 and Displacement to .05 (this is just more guess and check work)
While you are in the Material Editor you can also add a Reflection layer to make the surface a bit glossy, as if the wood planks have been varnished. The default value of 1.0 will be far too high; set the reflection and highlight values to .05.
- More on the Material Editor
- Applying Materials to Objects and Layers – Concrete Walls
A concrete material will be applied to the walls and ceiling in through the same steps that the wood floor. This time we will be using a .vismat material. Vismat files often include a reflection layer and image bumps. In this case we will delete the reflection layer as we want the concrete to be totally matte. Adjust the sale of the texture in the properties menu; use box mapping.
Now that we have added texture to the walls and floor the scene seems a bit too dark. Change the shutter speed on the camera to 50.0.