Updated: Feb 2
This page contains our tried and true process for taking still from a 3d modeling program and creating a hybrid collage-photorealistic render. You can use these methods in any modeling and photo-processing software. This example includes exporting images from SketchUp 2016, image editing in Photoshop CS6, and rendering in Kerkythea and V-ray.
Alternatively, you can watch this video
Creating the Base Render is the first step I use to create a quality visualization or illustration. It adds elements such as depth, shadow, definition, and structure to the image.
Keep in mind that this post focuses on introducing a workflow that creates a well organized Photoshop file as well as a few techniques that develop the elements mentioned above. I show exactly what you get with the steps I go over, but you can use many more tools in both SketchUp and Photoshop to further develop the render towards a particular style.
Exporting Files from SketchUp
(or any other 3d modeling program)
The file I am using for this tutorial is an old project from a semester abroad in which we designed a bridge that included mixed program in Amsterdam. At this point, the model could continue to be developed with small details, however I find that these would be easier to work out later in Photoshop. The point at which one decides to transfer from 3D modeling to Photoshop can be critical when time is a limited factor. The image below shows that the project and the surrounding has quite a good amount of detail, and enough context is developed to give a good sense of the relation the project has to its surroundings.
There are four (4) images that will be exported from SketchUp:
4. Clay Render
The format I use in this post has a whole screenshot of what I can see, accompanied by a detail of what the action is for a particular step.
To set up the line view, make sure you first set up the scene for your site plan. You do this by opening the Scene window on the right and clicking the (+) symbol. Once that scene is created you can double-click on it to switch back to that view. I also save at this point as a new SketchUp file in order to use the previous as a base file for any other views I wish to do specific edits for.
After you have created your scene, open the Styles window on the right. If your are using an older version of SketchUp, click on Window at the top bar of the program and select Styles.
Choose the Default style, and open the style editor by changing from the Select tab to the Edit tab.
Here, click on the brown box which should make the label to the right read Face. Then click on the white box (hidden line) found under Style to take away color from all faces in the model.
Make sure to turn off shadows or any other visual elements other than the lines before proceeding.
The view is now ready to export the first file, to do this follow File>Export>
The export window should now pop-up.
Create a folder to contain all your base files in one place, preferable inside another folder for the entire view. Make sure you export a JPEG file.
Next, open the options dialogue found at the bottom of the window.
I use a resolution width of 3600 which defaults the height to 2223.
Copy the second number with Ctrl+C (Cmnd+C on Mac) if you have trouble remembering it to use it later.
If you are rendering with Kerkythea, use 1600 as your width and copy the resulting height.
Moving on to the next image to export, in the Style editor where the face settings were changed click on the box appearing in wireframe. The label to the right should now read Edge.
Now, back to the face settings in the Style editor switch to shaded mode as shown below.
Your model should now look something similar to what is below. Make sure that the view you are using is the same as the scene you exported as your lines file. To do this, double-click on the scene in the Scene window on the right to return to that view.
Repeat the export process with the same resolution as with the previous view.
Once more, keep all lines off in the Style editor and switch back to hidden line mode in the Face settings.
Next, open the Shadows window and click on the shaded box on the top left corner to activate shadows. Use the various settings to create appropriate shadows for the view.
Export the image below which should only contain shadows.
The first step to performing any render on V-ray is to open the Options window from the V-ray toolbar. It looks like a price tag with an "O"
There are several tabs that are organized in a vertical fashion with centered labels. Under the top tab labeled "Global Switches," check the Override Materials box and select a light grey color as the override color.
Click on "Global Switches" to close that tab, and now open the "Output" tab.
Input the same resolution here that was used earlier to export all the other images from SketchUp. If you are using V-ray it was 3600x2223
Also, check the box labeled "Save output" and then select the destination of the "Output file."
Close the "Output" tab and close the V-ray options window. Click the "R" inside of the blue circle to initiate the render.
In order to render with Kerkythea, a .xml file must be exported and then opened in the Kerkythea program for rendering.
Select the export button in the Kerkythea toolbar to initiate the export.
Select the Clay option as "Yes" as well as all other settings as shown below.
Once the export has finished, SketchUp will ask if you want to open the file in Kerkythea, select "no."
Launch Kerkythea and open the newly exported .xml file from File>Open.
The model should appear in wire frame as default, but to change this click View>Adjust>Solid Rendering from the top toolbar.
Note: If you still cannot see anything, you probably used parallel projection instead of perspective from SketchUp. You can start over if you wish to have the images overlap perfectly as a perspective. Otherwise, simply zoom out until you can recognize the model and fit your view around the central bounding box. You will have to transform (Ctrl+T) this particular image in Photoshop later to match it to all others.
Next, from the same toolbar click Settings>Scene.
Make sure to select Soft Shadows and click the drop down menu under "Attenuation" to select Inverse.
Finally, click the icon with the running man in the green circle and input the following settings followed by OK-
If you cannot see the render happening, click on the Image button (landscape picture next to the "running man").
Before moving on...
These are all the images you should have at this point:
Clay Render (V-ray)
Clay Render (Kerkythea)
This portion of the tutorial will first explain how to organize the layers created in SketchUp in order to introduce new aspects to the render in
Part 2. I will introduce a technique and then a Blend Mode option for each step, and every step will work with one of the layers we have created. These techniques and blend modes can be used differently than how I do depending on what you are trying to achieve.
The images you export from SketchUp should overlap perfectly as long as you used the same resolution for each. I will follow by using the images at 3600x2223, but the steps are exactly the same no matter the rendering software used.
On the toolbar at the bottom right corner, select the Folder icon to create a new layer group.
Next, select all the layers by clicking the bottom layer, holding Shift, and clicking on the top layer.
The layers here are outside of the group.
Drag the selected layers over "Group 1."
The layers now appear shifted to the right, indicating they are part of the group.
Name the group "Base Render" by clicking and holding for a second over the current name.
Note the layer order I am using, and right click every layer to "rasterize" them in order to perform the following steps.
Click on the eye that appears to the left of the layer to hide that layer.
For now, hide Lines and Shadows.
The following techniques are applied to the Clay layer. This is the layer that will add depth and will make the image read well spatially.
With the Clay layer selected, Click on Image>Adjustments>Hue/Saturation.
I normally de-saturate the image as shown below to get rid of most of the default blue tint, as well as slightly lightening the image for better contrast in the next step.
After accepting the previous settings, click on Image>Adjustments>Levels
There are three "nobs" under "Input Levels" with numerical values: the dark, the white, and the mid-tones. Below, I have moved the dark and white closer together and then adjusted the mid-tone nob (center arrow) to achieve a good contrast.
The final move for this step is the same final move I will use for all other layers: selecting a blend mode. The blend modes appear in a drop down menu above the layers. For now, I am using Multiply for the Clay layer.
This layer will be used to make the surfaces read very clearly, which is something that will be well appreciated in Part 2 of the tutorial when working with textures.
Begin by making the Lines layers visible again and then right clicking it to duplicate it. Hide the original lines layer after duplicating it.
With the duplicated layer selected, click on Filter>Blur>Gaussian Blur...
I am using 5.3 Pixels in this example because its enough to make the line lose sharpness, but still defines a boundary.
Finally, the blend mode I have chosen for this layer is Overlay, however Linear Burn works very well too.
The shadows layer will add a primal element of realism to the image as well as inform the vertical qualities of the project and site.
First, I want to make sure that the layer contains nothing but the shadows, so I will eliminate the negative space.
Click on Select>Color Range.
Click on the white space of the image to select the lighter tone in the layer (NOT the shadows).
Use the "Fuzziness" nob to define, or blur the selection outline.
Click OK when the desired selection is achieved.
Next, hit the delete key to eliminate the negative space, and then de-select by using Ctrl+D.
Use the eraser tool shown below at about 30% opacity with a soft brush to lightly lighten the shadows that reach far away from the mass they originate from.
The blend mode I have chosen to use for this layer is Multiply.
This image now constitutes the base onto which textures, details, architectural, and landscape elements can be added to bring the project to life in Part 2 of the tutorial. Again, the techniques I showed do not have to be applied just to the layers I have used them in. Using these techniques on all layers can really add some quality and style to your render!
I organize my folders differently depending on the type of illustration (section, plan, perspective, etc.). In this case, I created a folder for every single texture and detail item.
Start by duplicating the Textures layer from Part 1 and place it above the Base Render folder. Next, create a new folder labelled Grass and place the newly copied Textures copy layer inside.
Duplicate the Grass folder to create a folder with a Textures layer for every single texture you have in the site plan.
Rename all the folders appropriately so that there is a folder for every texture.
The reason for this step is to use the SketchUp image to cut the textures with a Clipping Mask rather than cutting out the textures. This allows for much more graphic flexibility.
On the Textures layer within the Grass folder, use the Select>Color Range technique explained in Part 1 to select only the green areas of the project.
After applying the selection, hold Ctrl+Alt+I (on Mac it's Option+Alt+I) to inverse the selection. The selection should now be everything BUT the target texture. Press the delete key to create empty space in the layer around the target texture (Grass). This is now your Texture Base.
Repeat the process for every texture layer within folders.
The example above shows the same selection done to the Rooftops folder.
This is where the textures are applied to the newly created Texture Bases. Notice that the following process is applied to every folder, and images can later be replaced by simply placing them in the correct place. The advantage here is that it provides a quick way to edit the illustration, as well as an easy option to improve it in the future.
Begin dropping in textures into their respective folders and placing them above the Textures Bases.
Make sure the texture layer is above the Texture Base layers within its respective folder and right click it to make it a Clipping Mask.
This should be the end result.
Below, I have scaled down the texture by transforming it (Ctrl+T) and placed it how I felt it provides the best aesthetic.
Since I scaled the texture down to small to cover the whole grass area, I duplicated the layer and placed it on the other location. Notice that the clipping mask remains on the new layer.
Before proceeding, make sure to rasterize the texture layers if they are so not already.
Dodging and Burning
The Dodge and Burn tool can be used to make the texture look like it belongs to the surface by brightening and darkening it. In this case, I am using the Dodge tool on the Grass layer to brighten the center and the Burn tool to darken the edges.
Select the Dodge tool from the toolbar and apply the following options:
After lightening the texture, click and hold over the Dodge tool to switch to Burn.
The last step to the texture editing phase ends with selecting the appropriate layer blend modes. Apply these blend modes to the folders containing the textures.
The details of the illustration are organized in the same way the textures are. A folder for every item, which can vary from project to project. As you can see, I have Trees, People, Vehicles, and other Details.
The folders mimic the workflow from the textures, except that there is no base or clipping mask for most.
Place all the tree images into the tree folder.
Use the Select>Color Range tool to eliminate the white space (if any). Turning the Fuziness higher will allow you to get the white in between leaves.
Press the delete key to eliminate the white on each tree layer.
There are a few techniques to make trees look unique. First, duplicate all the trees to compare them.
Make all the tree layers visible.
Use the transform (Ctrl+T) tool to resize and stretch the general shape.
Make sure to make copies to keep track of the variants.
You can also flip the tree to get a mirrored image in Edit>Transform>Flip Horizontal.
Use the Dodge and Burn tools explain earlier to differentiate them further by their lighting.
Continue to make copies and using these techniques to populate your plan. Below, you can see I have used yellow trees for the street, trees with low density for the park areas, and more dense trees for busy sidewalks.
Next, to create the shadows for the trees duplicate all the tree layers and merge them together. Both these actions are done by right clicking the selected layers.
Move the tree shadows in the direction that the shadows are cast. In my case, I moved it slightly up and to the right.
Move the tree shadows layer below all the trees while keeping it in the Tree folder-
As shown in Part 1, go into Image>Adjustments>Hue/Saturation and move the Lightness nob completely to the left (dark).
Trees should have some transparency so they don't overpower the image and show what's beneath.
Lower the Opacity of the Trees group. For my image, I made it 80%.
Lower the Opacity of the Tree Shadows layer a little further. I put mine down to 75%.