Please first understand that V-Ray is not a magic weapon that allows you to instantly create fantastic images. It is only one of the tools in your toolbox. For me, Photoshop is probably the ultimate tool, but that’s only my opinion and personal experience with the software. To me, I relate using SketchUp, V-Ray and Photoshop to building a real model. SketchUp is the mold and V-Ray creates the model formed from the mold. Photoshop is then used to refine and add the ultimate details to the model.
Having knowledge of photo composition, if possible, is ideal. Understanding perspectives and how a good photograph is put together is critical. Analyzing striking photos, reading photography magazines and books, will definitely help you understand what makes a good image.
I am not using the latest version of V-Ray for SketchUp so the settings and names of settings will differ slightly if you are using the latest version, but it should be very similar. The settings in this tutorial created the sample images below.

Pool Image 1

Pool Image 2

In the images above, the water material was very fiddly to play around with. In other tutorials, I will have advice on materials. Bear in mind that these settings are quite high and take a while to render. I will highlight some points which you can change to decrease the quality and render time for test renders.
Let’s begin….
First thing… where is the options tab on the toolbar after installing V-Ray?

Options Tab

Global Switches
Only thing I touch here is override materials. This does what it says… when you render, it will override every material to the Override Material Color.

Global Switches

Image Sampler

Use Adaptive DMC as your image sampler. On previous versions of V-Ray, this may be known as, I believe, QMC. The anti-aliasing filter softens edges producing better edge results. I always have this on. Different filters produce different effects. For architectural renders, often it is good to use the Catmull-Rom filter as it produces sharper results. However, it can sometimes produce a moire effect. The Color Threshold value can be reduced to say 0.1 for faster test results.

Image Sampler

Caustics
Quite a difficult feature to use. It creates the shimmering results seen in the render above. Caustics also create the light effects you see when you shine a light through a diamond, for a example. It takes up a lot of render time and is not always necessary. Usually, I turn this feature off.

Caustics

System

Only setting I use here is the DR setting, which means distributed rendering. This allows multiple PC’s to be used for one render, sharing the power of the PC’s. You need to input the IP address of each computer in there, as well as having the program DRSpawner on each of the PC’s (which comes with V-Ray), if you choose to use this.

System

Displacement

Unless you have materials with displacement, this setting need not be changed. 1000 Subdivs provides decent results.

Displacement

Environment

GI Color controls the lighting that affects the image. BG Color does not affect the lighting but only creates the background of the image. Unless it’s something special, I keep the texture of each as Sun/Sky.

Environment

Camera

This is where you’re photography skills can pay off. I always use the Physical Camera which essentially acts like a real camera, where you can change the shutter speed, ISO, F number, etc.

Camera

VFB Channels

These are additional channels that will also be rendered should you wish to. As a default, RGB color and Alpha are required. Some of the others can prove to be quite useful when using in post production. I haven’t used many of them, but one that I have used is Render ID, which differentiates materials by color.

VFB Channels

Output

Here, you can change the final output size. You can also choose to render directly to file or render to something called a VRImage. This is useful should you wish to render a large file and you are running low on memory. However, you will need an extra program found on the ASGVIS website, to convert the file to OpenEXR.

Output

Indirect Illumination

GI (Global Illumination) – always on. Ambient Occlusion is a new feature in the latest version of V-Ray. Very useful tool that helps create wonderfully realistic results. The Primary Engine, I always use Irradiance Map and Light Cache. DMC/QMC really eats up time, so I would not use that… plus it doesn’t give great results.

Indirect Illumination

Irradiance Map

The Min Rate and Max Rate can determine the quality of the render. Play around with it to see the different results. Always keep the Min Rate at a negative value. The HSph. Subdivs also control the quality. 50 is quite decent, but for higher quality renders, a value of 100 can be much better. However, this does greatly increase the render time once again.

Irradiance Map

Light Cache

The default value of 1000 Subdivs produces rather good results. I never go beyond it. However, for test renders, I would lower that value way down to the values of 100 or so.

Light Cache

DMC Sampler

The default Adaptive Amount value is 1 on previous versions of V-Ray. Make sure that this value is changed to 0.85. Just do it! The noise threshold value here is 0.01. This produces quite good results and a sharp image. You can reduce this value to say 0.1 for quick tests.

DMC Sampler

Color Mapping

Play around with the Color Mapping type to test the results.

Color Mapping

Thats it! …I hope this somewhat comprehensive tutorial will help you in some way or another and thanks for reading it. Here are some resources I have found useful in learning more about V-Ray and rendering.

ASGVIS Forum - this website is the home of the V-Ray for SketchUp forum. Many professional users reside here and can answer many of your questions.

Spot3D.com – is a very useful website. The tutorials and information are actually for V-Ray for 3DS Max, but there are a lot of similarities between the programs and you can learn a lot there.

Thanks



Steven Man

Lets get started!
1. In SketchUp, save a Scene under View>Animation>Save Scene, that you want to use for the illustration that way you can get back to the same view later if need be.
2. Switch the Face Style to “Hidden Line”. Under View>Edge Style, check “Display Edges.” Make sure Shadows are off.

Step 2. Change Face Style

3. Go to File>Export>2D Graphic and save the image as a JPEG.
4. With the Face Style still set to “Hidden Line”, turn on Shadows and again export the image as a JPEG.

Step 4.Turn on Shadows and Export Image

5. Now, switch the Face Style from “Hidden Line” to “Shaded with Texture.” Again, export the image as a JPEG.

Step 5. Change Face Style to Shaded With Texture

6. With the 3 images complete, it’s time to combine them in Photoshop. Begin by opening the first image (SketchUp export with only line work, no shadows) in Photoshop. Right click on the Background layer (Click in the space next to name of the layer) and choose “Duplicate Layer”.

Step 6. Duplicate Layer

7. At the top, select “Filter>Blur>Gaussian Blur”.

Step 7. Apply Gaussian Blur

8. When the dialogue box appears, choose a Radius of about 6.5. This number may need to change depending on the resolution of your image.

Step 8. Choose Radius

9. With the lines now blurred, we need to darken them. I prefer to use Levels although you can probably get away with adjusting the contrast. For Levels, go to “Image>Adjustments>Levels”. Move the left black triangular slider to the right until the line work darkens to almost black.

Step 9. Adjust Levels

Below, is what the image should look like at this stage.

Image so far

10. Next, duplicate the layer just created and move the new layer to the top. This duplicated layer will be blurred again using the Gaussian Blur filter. However, use a higher Radius such as 35 this time.

Step 10. Duplicate Layer and Apply Gaussian Blur

11. I want the original line work Layer to show through the two, now blurred Layers just created. To do this, select the two blurred Layers and set the Layer blending mode to “Multiply”.

Step 11. Set Blending Mode to Multiply

12. The next step is sort of the “secret sauce” of the tutorial.

a. Open the SketchUp exported image that showed both the line work and shadows.

b. Drag the new Layer to the top of the layer stack. Set the Layer blending mode to “Hard Light”.

Step 12a. Open Line Work and Shadows Image

Step 12b. Move to Top and Change Blending Mode

13. Add some color to the image.

a. Open the SketchUp exported image that had the face style “Shaded with Textures” turned on.

b. Drag the new Layer to the bottom, just above the “Background” Layer.

Step 13a. Open Shaded with Textures Image

Step 13b. Place Layer above Background Layer

14. I like to add color overlays to my illustrations to give them more of a mood. Create a new Layer and move it to the top Layer. Select the “Brush Tool”, and adjust its settings to have 0 Hardness as well as lower the Opacity down to 25 to 30%. Begin painting in areas where you want more color.

Step 14. Add Color

15. Set the Layer blending mode to “Overlay”.

Step 15. Blending Mode to Overlay

16. One last thing, I want the shadows to be a little more darker. To do this, select the Layer with lines and shadows that was set to “Hard Light” in Step 12 and “Duplicate” it. Now, select the new duplicated Layer and change the Layer blending mode from “Hard Light” to “Multiply”. You can adjust the Layer Opacity if the shadows are too strong.

Step 16. Duplicate and Change Blending Mode to Multiply

For the final shot below, I added some vignetting (Tutorial Here). I also overlayed another exported SketchUp image with the face style set to “X-Ray” mode for more detail in the light areas of the illustration.

Final Image

That’s it! It may seem like a lot of steps, but I think once you go through them a few times, you will realize they are relatively simple and the whole illustration can be created in a matter of minutes. I hope you found this tutorial useful and you can maybe introduce it into your own workflow, especially when you need something really quick and simple!
Thanks for reading..

Alex Hogrefe

To get started, 3 images will be generated which will be used in Photoshop. Two of them will be exports from SketchUp, and one will be a basic rendering from the free rendering software Kerkythea.
1. First Image – Base Image
a. In SketchUp, save a scene that you want to use for the illustration. That way you can get back to the same view later if need be.
b. Switch the Face Style to “Hidden Line.” Under View>Edge Style, check “Display Edges” and “Profiles.”

Base Image

c. In the Styles dialogue box, select the “Edit” tab, choose the “Edge Styles” icon, and check “Extensions.” Set the length to 8 pixels.

d. Export the image as a JPEG by clicking on “File>Export>2D Graphic.”

Styles Dialogue Box - Check Extensions

2. Second Image – Guides

The point of this second export will be to imitate guidelines seen in hand drafted illustrations back in the good old days.

a. Select “View” and check “Guides in SketchUp.”

Check Guides

b. With guides turned on, begin creating guides that accentuate important axis or angles in the image. To create guides, measure something with either the ruler or the protractor. Whatever is measured will then turn into a guideline.

Create Guidelines

c. With the guides in place, go to File>Export>2D Graghic and save the image as a JPEG. Again, use the Face Style “Hidden Line” and leave only “Display Edges” checked for the Edge Style.

3. Third Image - Basic Kerkythea Rendering
This Kerkythea rendering is very basic with minimal setting changes. The rendering itself only took 10 or 15 minutes to finish because of the limited use of materials.
a. To begin, export the model from SketchUp using the Kerkythea plugin. Be sure that Shadows are on and that the view you want is set. In the export options, follow the settings below double checking that “Clay” is set to “Yes.”

Kerkythea Export Settings

b. Open exported model in Kerkythea. At the top, select “Settings>Scene.” In the scene settings dialogue box, choose “Inverse” in the attenuation drop-down box. The setting will give you soft shadows similar to what you would get on a cloudy day.

Scene Settings

c. That’s the only setting that needs to be changed. Time to render. At the top, select “Render>Start.” In the dialogue box, Do Not change the resolution. However, do change the “Settings” to “07 PhotonMap – High+AA03.”

Kerkythea Render Settings

d. Let the rendering cook for a few minutes. To preview and save the final rendering, choose “Window” at the top and check “Rendered Image.” With the preview box open, select the “Save” button to save the image to your hard drive.

Save Rendering

4. Photoshop Work

a. With the 3 images complete, it’s time to combine them in Photoshop. Begin by opening the first image (SketchUp export with extended lines) in Photoshop. Choose “Image> Adjustments>Invert.”

Invert First Image in Photoshop

b. Next, open the Hue/Saturation dialogue box by going to “Image>Adjustments>Hue/Saturation.” In the dialogue box, first check “Colorize.” Move the “Lightness” slider to the right to lighten the black background to a grey color. Next, move the “Hue” slider until you end up with a nice blueprint color.

Create Blueprint Color

c. Place (or copy and paste the image on top, it will line up perfectly then) the other SketchUp exported image with the Guides and make sure its the top layer. Again, “Invert” the image so that the line work becomes white on a black background.

Place Image on Top and Invert

d. With the Guide layer still selected, set the Blending Mode (drop down box top left in the layers pallete) to “Screen.”

Set Blending Mode to Screen

e. Open the Kerkythea rendering and drag it to the top layer (or copy and paste). Desaturate the image by choosing “Image> Adjustments> Desaturate.”

Desaturate Image

f. The image is a little flat. Adjusting the Levels will fix that. Adjusting the Contrast would also work, but I prefer Levels because of the added control. Choose “Image>Adjustments>Levels”.

Adjust Levels

Move the sliders until you end up with lighter and darker tones similar to the image below.

Levels Adjusted

g. Making sure the Kerkythea rendering layer is on top, set the Layer Blending Mode to “Multiply”.

Set Blending Mode to Mutiply

h. The illustration is almost finished. The last step is to add some texture to imitate the texture created from the blueprint chemical process. To do this, I just went online and found a “grunge” texture similar to the one below. Open the texture in Photoshop and move the layer to the top.

Grunge Texture

Finally, set the Layer Blending Mode of the grunge texture to “Overlay”.

Set Blend Mode to Overlay

That’s it. The first time I created this illustration, it took me about one and a half hours to make, including testing different settings and waiting for Kerkythea to render. Now that I have the workflow down, I’m guessing it would take about 30 minutes to create subsequent illustrations. The techniques are pretty basic, but it’s finding the right combination of layer blend modes and textures that give the final illustration a unique character.

Final Image

I hope you found this tutorial useful and interesting. Maybe introduce it into your own workflow, especially when you need something really quick and simple!
Thanks for reading..


Alex Hogrefe