CanVis: Photorealistic Visualization
This publication provides instructions for using CanVis photorealistic visualization software developed by the National Oceanic and Atmospheric Agency and the National Agroforestry Center. This free software allows users to visualize changes made to yards, gardens, and other landscapes by using photographic simulation. Users can test the way a landscape design looks before picking up a shovel! CanVis is similar to Photoshop, but it’s easier to pick up. Exercises in this article will help beginners become familiar with the software.
Tips for Creating Photorealistic Visualization Projects
- Use visualization to tell a story. This means making the visualization as realistic as necessary for the purpose of the project. Angle, scale, and lighting should be relevant to the project objective. The amount of detail depends on the project objective; for example, a conceptual mock-up may not need a lot of detail to get the point across.
- When displaying or comparing before and after products, clearly label the pre-simulated picture and the simulated result.
- Consider the presentation of the results. Will you print the final product, turn it into a PowerPoint presentation, create a report, or make a poster? The visual quality of the simulation makes a difference based on the final product.
- Beginners should use a picture taken on the same level or plane as the desired landscape for the base photo.
- It is easier to create a wanted background and replicate it than it is to cover up an unwanted background.
- Remember to use the correct perspective and shading.
- Beginners may want to avoid a large amount of sky in their base image because it can be tough to replicate the cloud and sky shading realistically.
- Do not use BMP or TIFF images as a rule of thumb.
- Cluster cover-ups like shrubs and grasses to make lines less visible.
- Start a database of photos that you can edit to create objects to add to your object library. CanVis’s included library is limited.
Download CanVis Software from the NOAA Website
Download Object Libraries, Objects, and Base Images
Objects can be downloaded from the CanVis website, or you can upload your own objects.
- Your CanVis software automatically comes with some objects. Objects with transparent backgrounds are saved as LOB or tga files. Instructions on making your own Object LOB/tga files are provided later in this publication (see page 8).
- You can also download objects from the CanVis website. For example, from the CanVis website, scroll to “Commercial-Urban Object Libraries” (under “Coastal Object Libraries”), and click on the link.
- You probably don’t need to fill your hard drive with all the provided libraries (Full Package), so download libraries relevant to your work (for example, coastal vegetation, people, parks and urban areas, symbols, transportation, walls, and buffers).
- Your computer may, by default, download a zipped folder to the Downloads folder. You will have to double-click to unzip it.
- Next, in the CanVis software you downloaded to your computer, go to Library on the main menu, then New Library; select Object Library for objects, or Texture Library for textures; give a name to your new library (for example, “Example Library”); and click OK twice.
- After that, click on the main menu Library, select your new library from the list, click Items, click Add Items, navigate to the appropriate folder, and select Items To Add. To see these files, you may have to change the file type to LOB or tga. Click Open. The objects will appear in the preview window. Next, still in the new library window, click on Library, Save Library, and click yes. Close the window.
- You can retrieve base images from Google Maps or Google Earth. Copy a satellite image or street view to your computer’s clipboard. Open it in the Paint application (or some other photo editing application) to edit. Then open it in CanVis as a base image (explained below).
- You can also use digital camera photos or scanned images. Scanned images should be 100 DPI for 8 x 10 photos and up to 166 DPI for 3 x 5 photos. A digital photo should be taken at 800 x 600 screen resolution. It’s preferable to take large DPI photos because you may need the pixelated detail, and you can always lower the resolution (file size) on the computer. You cannot increase DPI. Take photos on an overcast day or have the sun to your back to avoid harsh shadows. If the area is large, shoot in segments and make your design in pieces. Take the photo from a spot perpendicular to the area to be designed (shoot from the front, not at an angle). Clean the area before taking photo—remove unwanted and unnecessary elements.
Area Selection and Manipulation
Use this tool to create or fill an area (texture) or object. To place a texture in your image, use the Drawing Tools in the Texture toolbar. Click the Outline Area icon to open the Define Area toolbox. In the toolbox, there are three rows of icons. The top row is the Add Mode (default) and Subtract Mode. Add Mode creates one big area out of a series of smaller areas. The Subtract Mode allows you to cut a shape from that added area. It only works when you create the bounding box first, then use the Subtract Mode to subtract the area, then add the texture profile to the modified area. You might use this tool if creating a planting space in a wall, for example.
The second row contains the Drawing tools (Freehand Draw, Square Draw, Ellipse Draw). Let’s give these tools a try. Click the Add Mode and the Square Draw tool (in the middle). Try drawing several large squares. Then fill one of those areas with a texture by clicking on the Perspective Library in the same Define Area toolbox (or Perspective icon on the toolbar if you have closed the Define Area toolbox). Make sure the correct angle and distance are used to make the texture realistic (see Change Perspective below). Click OK.
Next, try creating outlines from the Freehand Draw tool. In Freehand, you have to come back to the first point to close the polygon. Before adding a perspective and without clicking the cursor outside your new area, try using the Add, Delete, and Move icons on the third row to add a point, delete a point, and move a point from the outline. Notice how the cursor changes when you select these tools. The cursor must be placed exactly on the point to move or subtract it (you may have to zoom in to select the point). In Freehand Draw, you can hold down the shift key to confine the line to 45 degree angles. Also in Freehand, by pressing the backspace button before you close the polygon, you can undo the points in succession so you don’t have to start over completely if you make a mistake. Edit tools only work with points and will not move lines. Use these edit tools to reshape your area. You can always click Cancel to start over or click OK when you’re satisfied. Your outline is now ready to add a texture using the Perspective Library. Note that once you add a texture, you can’t make shape changes.
You can replicate part of your background image using the Outline Area tool. Click on the Outline Area icon. Use the draw tools to define an area. Click OK. With the area still selected, select Area from the main menu, then Convert to Object. Now you can replicate (below) or copy and paste the background area that you made into an object.
You can quickly change a texture profile. Select the texture you want to change. Click on the Texture Library button on the Texture tool bar. Select the texture library you want. Select the profile you want to see in the design. Holding down the left mouse button, drag the profile onto the image (notice cursor changes) and drop it. The texture will now change to the perspective and scale of the previous profile.
The Perspective tool makes textures look like they are visually correct. For example, to make a roofing profile follow the line of the roof or make a groundcover look like it’s going into the distance, you should use the Perspective tool. Select a texture for which you want to change perspective. Next, click on Area in the main menu, then change the texture’s perspective by selecting the appropriate setting (Roof is the most versatile) and moving the corners of your texture to get the right perspective. Roof allows movement of all the corners independently. Siding locks the side corners together to create the illusion of the texture lying straight on its side. Paving locks the top and bottom corners together to add the perspective of lying down flat. Use the slider bar to match the scale of your background image. Click OK.
This is on the Advanced toolbar or under Tools in the main toolbar. Pick the size and shape of brush. You can paint using a texture (from a library), pick a color from the existing background pixels (Pick Color), or select a color from the color palette (Choose Color). If you select a texture from the library, remember to adjust the scale. To paint with that texture, place your cursor over the area to be painted, left click, and drag. You have to use this tool in an area where the angle is not important because you can’t use Perspective for painted textures. Click undo if needed.
Object Color and BlendingAdjust Colors:
Click Adjust Colors under the Tools in the main menu or the Adjust Colors icon. Select an object to modify and adjust the red, blue, or green colors of the object. Note preview in toolbox window. You can click reset and start over if needed.
Use Color Levels to improve the image quality of an object or background. Click Tools, then Color Levels. Adjust intensity and contrast using the slider bars.
Use Colorize to change the color of the background, object, or texture. If it is an element (Object or Texture), select it, and from the main menu, go to Tools, then select Colorize. In the toolbox, you can select a color and add it to the selected element. You can change the color swatch by dragging the slider bars. If the feature you want to color is part of the background image, you must define (outline) the feature first. Using the Outline Area tool, define (outline) the feature, and click OK. Now open the Colorize tool to add the color you want. Alternatively, you can select Pick Color in the Colorize toolbox, then left click the “dropper” cursor on the color you want. Note the swatch change.
Object Editing and ManipulationLayers:
Every object or image has its own layer determined by the order in which you added them to the project. The layer tools allow you to shuffle the layers. From the main menu, go to View, then check the View Layer toolbar to open. The toolbar’s options include, from left to right, the Zoom tools, Object to Front, Object to Back, One Layer Up, and One Layer Down. Select the object that is on the lowest layer and move it to the front using the Object to Front button. Then, move it to the back with the One Layer Down button. Next, bring it forward layer-by-layer using the One Layer Up button.
To make copies of objects in your project, select the object or texture, then select Replicate on the Object toolbar on the main menu. Place the arrow cursor on the spot where you want the object copied, and left click. To deselect, use the right click button on the mouse, and the cursor returns to normal.
Select the object, go to Rotate on the Object toolbar, click the corner anchor on your object, and move the mouse to rotate the object on its axis. Right click to deselect Rotate tool.
Select the object. In the Object menu, select Flip to flip horizontally or vertically. This is useful when positioning objects where facing direction is important.
Select the object, then click Erase on the Object toolbar. From the Erase toolbox, select the brush size and shape. Place the cursor over what you want to erase, then click and drag. Click Unerase to paint an erased portion back in. If you want to undo your last move, click Undo. Note that erase does not function on the base image.
Smudge helps to blend objects or an object and background. Select an object. Go to Tools on the main menu, select Smudge. Select the size of brush. Place the cursor over the object to soften the edges and blur the detail. To change the transparency, right click on the object and change the transparency in the bitmap box to create the illusion. Smudge can be used to blur the background, but this is seldom an objective.
You may have several defined areas with the same texture and different perspectives. You may want to change the texture at the same time while keeping the perspective (think changing a walkway). Click on one area, hold down the shift key, and click the other areas individually. In the main menu, under Area, select Create Texture. In Texture Library, select the profile by clicking once. Hold down the mouse button and drag the profile to the texture in your project you want to change. Release the mouse to change the texture profile. The same process applies to changing a set of objects (for example, plant material). The same idea applies to grouping objects. You can group several objects, then go to the Object menu on the main menu and select Merge Objects to create one object from the multiple objects. This merged object can then be replicated across the base image.
Warp is like Perspective, but for objects instead of textures. Use the Warp tool, found in the Object toolbar, to make objects that are photographed from the front go on an angle. For example, make a fence run down the side of the yard or make a gate look like it is open. For an “object” to lie down or be placed on a vertical surface, you need to use the Vertical setting. This links the two side corners of the bounding box together. Now take the bottom corner of the bounding box and click and drag it up and out (toward the outside of the picture). Now it appears to be lying flat. The top corner may have to be lowered a little, as well. The Free setting in the Warp toolbox is used for irregular objects. Use it on any object that doesn’t stand vertically or horizontally.
Go to the Lighting toolbar in the View toolbar, or select the Day/Night icon. To add a ray of light (for example, from a streetlight), you’ll need to click on the dusk, dark, or night icons in the Lighting toolbar to create darkness if your base photo was taken in full daylight. Next, click on the Lighting tools (the lightbulb icon). You can use the Spread method or Paint-with-Light method to illustrate light. The software defaults to the Paint-with-Light method. However, Spread is more useful for creating light from streetlamps. Next, select the size and shape of brush
you want. Now, set intensity and light width using the slider bars. The intensity bar is how dim the light is, and the light width is the amount of pixels the light will expand. Make sure the intensity and width are adjusted so that they are visible. You can erase the light by clicking on Erase Mode and drawing over the light line. By using the Spread tool, you don’t need to select the brush. Adjust the intensity and light width. Point where you want the most intensity to be, then drag your cursor to define the shape you want. Turn off the Lighting tool bar by clicking on the Day/Night icon.
Select the object from which to create a shadow. Left click once on the Shadow icon from the Object toolbar. Deselect the object and move it so you can see the shadow. You have to select the shadow, then right click to change its transparency. Because the shadow is an object, you can rotate, flip, resize, and warp the shadow.
Magic Wand Tool (Creating LOB/tga files):
The Magic Wand tool is used to create your own library objects. Start with a photo using the acceptable image quality described previously. After you have selected an image, you should first remove as much of the background as possible using a photo editing program on your computer.
First, open a new document and colorize the background (Tools from the main menu, then select Colorize). Pick a color that doesn’t appear in the image you want to put in your library. Import your selected image (File, Import, Open) into the new document background. Now create a transparent mask. Select the imported image. Click on the Magic Wand icon on the Advanced tool bar or go to Tools on the ribbon, then select Magic Wand. In the toolbox, set the background color to something unique, like bright red. Set the exclude tolerance to 10% to start. This is a repeated process—you will work your way down. Place the Magic Wand cursor over the area of background where you want to create the mask (in other words, excluding those pixels), and left click. Some of the unwanted area has been selected, but it may not be enough. If it’s not enough, you can increase the exclude tolerance. If it’s too much, click undo and decrease the exclude tolerance. Continue this process until most of the unwanted image is selected. Use the erase tool to clean up the remaining pixels. Click OK when you are satisfied. Now all the areas of the mask are transparent. Once the image is fully edited, export it as a LOB/tga and save to your computer. You will have to add it to a library to use it (explained previously).
Publication 3198 (POD-03-18)By Jason Gordon, PhD, Associate Extension Professor, Forestry.