Select the Matte object checkbox, and change alpha contribution to -1.Īlpha contribution=1 is solid, with no transparency, 0 is transparent by itself, but still shows anything behind it, and -1 is transparent blocking everything behind: Right-click the "shadow matte" object and go into the V-Ray properties of the object: I have made a material for you already, it's in the top right corner of the material editor. Now assign a plain grey VRayMtl to the "shadow matte" plane. It needs to be approximately 2400 mm x 2400mm big. This is going to be our shadow matte object, so rename it to "shadow matte". I've done the basic setup for you already - you can always fine-tune it later if you want to.Ĭreate a Plane object under the chair. Your 3ds max viewports should look like this now:Īt this point you could move the Camera and the Sun to make the chair look as though it is sitting correctly on the paving. Remember to select Match bitmap, Display Background and Lock Zoom/Pan, so that the background stays the correct size in the viewport. Now load the background photo ("background.jpg") as shown in the screenshot below. Go to the 3ds max menu bar and chose View>Viewport Background. We also need to match the shadows created by VRaySun01 with those in the photograph. We need to load the background photo ("background.jpg") into 3ds max, so that we can match the perspective of the VRayPhysicalCamera01 to the perspective of the background photo. Open the file: "vray_shadow_matte_tutorial_start_file.max"
There is also a tutorial on LWF on my blog: Lukx () has made a simple video tutorial on LWF, it can be found here: Īversis also has a brilliant tutorial about LWF on his website: (You can change the Gamma settings in 3DS Max under: Customize >Preferences.) You also need to change the color mapping in your Vray settings, there are various options for this, I've shown one in the included file "LWF_VRay_Color_Mapping_settings.jpg" Please note that the max file used in this tutorial uses the V-Ray LWF (Linear Work Flow) technique, as described on the chaosgroup forums (To use LWF you need to change 3DS Max's Gamma settings - please see the included file called "LWF_gamma_settings.jpg" to see what your settings should be. In this file you will find two 3ds max files, a background photo and some additional info.
You will need to download the "vray shadow matte tutorial.rar" file from:
The purpose of this tutorial is to show you how to render out a 3D object, with its shadow included in an alpha channel, so that you can composite the 3D object and it's shadow on top of an existing photograph. To complete this tutorial you will need 3DS Max 2008 or newer, with V-Ray 1.5 and Adobe Photoshop. Welcome to this tutorial on making a shadow matte with V-Ray.