V-Ray Photomatch: Placing a Model into a Photo

Ufuk ŞEN

May 6, 2021Updated: November 9, 20265 min read1

We are back with another very valuable lesson. Our friend Ahmet Fatih, an expert on the subject, prepared the V-Ray Photomatch course set. The set used to be paid, and he gifted it to our site; we thank him here. Ahmet Fatih works on visualization projects at his own firm, Koda Mimarlık. You can reach him through his Facebook page.

In this article, we first explain what Photomatch is. Then we cover choosing the photo and the overall flow of the set. We also share tips that help when you take the model to the V-Ray render stage.

V-Ray Photomatch course set playlist

You can reach the lessons in the set in order from the list below.

The list currently has eight videos. The lessons range from 7 to 16 minutes. The total running time is about an hour and a half. To open the list directly on YouTube, click the Photomatch course set. (The video is in Turkish; this guide walks through the key steps in English.)

What is Photomatch?

Photomatch is a method of turning a photo of a building or object, taken from a clean angle, into a 3D model. You match the perspective in the photo with SketchUp’s camera. Then you trace over the photo to draw the model.

This method is especially useful for modeling existing buildings. For example, if a facade renovation project has no measured drawing of the building, Photomatch offers a quick solution. You also use the same technique to place a new project inside an existing photo.

Choosing a photo for V-Ray Photomatch

In the Photomatch workflow, one of the most important things is the photo itself. You need to take the photo from a certain parallel angle. Photos with crooked axes can be corrected in programs such as Photoshop. But the job gets much easier if someone who knows the subject takes the photo of the building you will model.

Corner angle: choose a corner view that shows two facades of the building together.
Lens: avoid the distortion that wide-angle lenses create.
Light: shoot on a cloudy day without harsh shadows.
Obstructions: find a spot where trees and vehicles don’t block the facade.

The render stage in the V-Ray Photomatch process

Once you have built the model from the photo, the work moves to V-Ray. The goal here is to make the model look as close to the real building as possible. So first study the light direction in the photo. Then place the V-Ray Sun in the same direction.

Also choose the materials to match those in the photo. For example, use a matte material if the facade is plastered, and a reflective material on the glass. We covered exterior facade render settings in detail in our V-Ray exterior facade render settings article.

The extension used in the lesson

In our original article, we said you could download the extension used in the lesson from the Download section of the video. But old links stop working over time, so here is an alternative too. We suggest searching for the current version of the extension on Extension Warehouse.

SketchUp’s own Match Photo tool is also the foundation of Photomatch work. You can find the official guide to the tool in the SketchUp Help Center.

The general method, step by step

We explained the basic steps on the SketchUp side one by one in our SketchUp Photomatch steps article. This article covers the render and presentation side of the set. We recommend reading the two together.

What is Photomatch good for?

Photomatch is not only for modeling existing buildings. For example, you can place a building you have just designed into a photo of a plot. The client then immediately sees how the project will sit in its real surroundings. It is also very effective in renovation projects. You show the existing condition and the new proposal side by side. The client grasps the change at a glance, and the decision process speeds up.

You can also use the same technique with interior photos. From a photo of a room, you can extract the walls and windows and try out a new furniture layout. In short, Photomatch is a versatile tool that brings a real photo and a 3D model together.

Common mistakes

The most common mistake we see is working with a wide-angle phone photo. In such photos, edges look curved and the axes never quite line up. Another mistake is starting to model without setting the scale. Define a known dimension, such as a door height, at the very beginning. Finally, don’t try to extract the whole building from a single photo; use several photos from different angles if needed.

If you want to take this topic a step further, see our SketchUp V-Ray 2.0 Interior Course Set and SketchUp V-Ray High-Quality Interior Visualization Course 01 articles. You can reach all the lessons in order through our SketchUp render guide.