3 Tips to Increase Photorealism Renderings using Vray – Have you ever asked yourself, how to produce good work so that it looks real in sketchups? Today Im going to show you 3 Tips to increase Photo-Realism in Your Renderings using Vray 3.6 for Sketchup.
Table of Contents
3 Tips to Increase Photorealism Renderings using Vray
Lets get started.
1. Use surface imperfections – increase photorealism
If you look at the objects in the real world, you can see that their surfaces always have some types of imperfections like dirt, scratches, or even fingerprints.
So when the objects in your renderings look too clean or too perfect, it will look a little unrealistic. Thats why its good to add some surface imperfections to the materials in your model. So how do you add surface imperfections to a material? First you need a special texture map called a surface imperfections map, which is a black and white map that represents imperfections like stains, scratches, fingerprints, etc. You can find these maps on Poliigon.com, which is a premium website for textures but there are some free textures as well. David Gruwier also has a collection of maps with free samples that you can find on his website : http://dgruwier.dk/textures.html
Once youve downloaded the maps, lets start Sketchup and open up the Asset editor. Go to the material tab and click here to Create a Material. Next, Ill set the diffuse color to white.
Now Im going to create a 25 by 25 square and apply this material to the surface and start the interactive render. Here you will see that its all white so lets go down to Opacity, and add the surface imperfections map. For this, I will use one of David Gruwiers free samples. You can see that nothing is happening, thats because the material is too small and the camera is too far away so lets zoom in a little closer.
Its still hard to see because we dont know how much to zoom in.
There you go! now we can see the texture in the viewport and we can know what it looks like when we zoom in. As you can see, since we are using the texture as the opacity map. Anything thats white is visible, and everything thats black is invisible. Now lets overlay this on top of another material.
Before we do that, Im going to rename the material we just created as Overlay Now Im going to choose a material from the library to use. Im going to use this Laminate wood material here. Next, lets create a blend material and set the base as the Laminate wood Im going to apply this blend material and see how it looks As you can see, the material is a little too small, so Im going to increase the sizing from 10 inches to 4 feet.
There we go, thats better. Now lets add a coat to the blend material, and set that as our Overlay.
There it is, you can now see some scratches on our flooring material. To make it more visible, drag this slider all the way to the right, and if you want to make it less visible then drag it to the left. You can always add another layer by using this button here. But before we do that, Im going to repeat the first steps and create a generic material. Set the diffuse color to white, then add the opacity texture.
Next, Ill name this Overlay2 Now go to the Blend material and add a coat, set it to the new overlay we just created. There we go, you can see that it added some smudges here. You can also turn each of these layers on and off like so. As you can see, with surface imperfections, our wood flooring looks less repetitive and more realistic.
2. Use Round Edges – increase photorealism
Like Ive mentioned before, in the real world, there is no perfectly clean surface; in the same way, there is also no perfect 90 degree edge in the real world. If you take a look at some objects with sharp corners, and zoom in closer, you can see that there is still a curvature, smoothness to that corner. However, in computer graphics, we get the straight lines and sharp edges by default. So to counter that, I recommend beveling or rounding the corners of your objects when necessary. For example this corner here looks fine when its far away, but when I zoom in closer, you can see that sharp edge that I was talking about.
To fix this, youll need an extension called Round Corner. Now to use this extension, first, select the edge or edges that you want to make round or bevel and click on one of these buttons to bevel the edge.
Ill use this first button for a round corner. Next you will see this interface pop up where you can make adjustments. In this case, Ill just click here to change the offset dimension to 2 inches and press Okay.
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Now left click on the outside of the object to execute the command. There we go, that’s how you use the extension. Also note that all of these buttons bevel your corner a different way. The first one gives you round corner, the second one is for sharp corners, and the third one simply bevels it. Now lets apply this to our model.
First we have to select the edge we want to bevel so Im going to double click the object until I have the group open.
Now lets zoom in closer, select the edge and click on the Round Corner button. Here I can adjust the offset value but I will leave it as 1/2 an inch. Press okay, and click on the outside of the object to execute it. There we go, but if you look closely, rounding the corner messes up our texture.
To fix this, make sure these geometries are in a group, then right click the group, and go down to Vray UV Tools Tri-planar-projection (world). There you go, that fixes the texture. Now lets compare the before and after. As you can see, with the round corner, the render looks more realistic.
3 Use Ambient Occlusion – increase photorealism
What is Ambient Occlusion? Ambient occlusion (or AO) is a shading technique that lets you create soft shadows in the cracks and crevices of your 3D objects when indirect lighting is cast out onto your scene.
Here is a comparison between two renderings with and without AO (ambient occlusion). As you can see, Ambient Occlusion can give more depth and definition to the geometry and add more realism into your scene. So how do you add AO to your renderings?
There are two ways, one is simple and the other is more advanced The first one is to use vrays built-in Ambient Occlusion setting To do that, go to the Settings Tab, click this arrow for more options, under the Global Illumination roll-out. Go down and turn on Ambient Occlusion Here you can adjust the radius, which determines the amount of area where Ambient Occlusion effect is produced.
And the other setting is the occlusion amount, which multiplies the effect of Ambient occlusion. There it is, now just hit render and youre good to go. The second method is to create an Ambient Occlusion Pass which you can use later to overlay on top of your Render in Photoshop.
To do that, first, go to the Render Elements roll-out. Now add an ExtraTex render element then click here and add a dirt texture map.
You can use these parameters here to adjust the effect, theres a lot that you can do here but I will make some simple adjustments and show you more settings in another video. After you render, you can access this render element in the Vray Frame Buffer window. Just click this drop down box here and choose ExtraTex.
Now what you need to do is save this render element along with your original render. Then open up Photoshop and put this layer on top of the original, and set the blend mode to multiply. There you go, you can now lessen or strengthen the effect by adjusting the opacity or even hide parts of the ambient occlusion that you do not want by using layer mask.
As you can see, the second method gives you more control over how you want Ambient Occlusion to affect your rendering. And those are 3 ways to make your renders look more realistic!
They are not that noticeable in your renderings but they can help take your photo-realism to the next level.
