Blender - the best free rendering software for architects

Introduction

Note: This article has been republished from https://uhstudio.com/posts/blender-for-architectural-design. uhstudio.com contains further tips and guides on using Blender for architectural design, including courses.

Video

Written Guide

Blender has many capabilities. As already mentioned, the capability I tend to talk most about is modelling. Yet Blender also has excellent rendering capabilities. In this guide, we will talk about how to set up a simple context for rendering with Blender. I don’t talk about modelling here, and the intent is that a model is either imported from Rhino, Sketchup, Revit, or another Blender model, so we are exclusively focusing on creating a render scene.

You will learn about free resources for grass, trees, and people that can help you achieve a better rendering result.

The scene will be completely decomposed so you can get a clear idea of how each part comes together in order to help you with your own scenes.

Ground and paths modelling and materials

The ground is a simple plane subdivided with edge loops that then uses a subdivision surface modifier with edge creases to make them sharper. Additionally, within geometry nodes, slight deformation with a noise texture has been added and another subdivision modifier on top.

The material for the subdivision is quite simple mixture between two colourse based on a noise texture. We mostly wont’s see the material of the ground plane as it will be covered with grass and other elements, but if it does, it is good to create a material that falls in the background and doesn’t look out place.

Remember, elements that look out of place may detract attention from what we actually try to achieve - present an architectural proposal situated in a site.

Next element, the paths are simple planes modeled flat, subdivided with a subvid modifier, and then using a shrinkwrap modifier, they are snapped to the ground plane. I’ve added a laplacian smooth for make them appear smoother and then a solidify modifier in order to make sure the paths don’t intersect with the ground plane.

Adding people with geometry nodes

Let’s add some people onto the paths. Here is a sketchfab model that contains lowpoly triangulated scaled people. We will use a simple geometry nodes tree of first distributing points on the faces of the path and the. Instancing the people from the collection onto the points.

Additionally there is a small filter that shows how to select only the faces with normals printing up from the path object, since we used a solidify modifier in the path and we don't want points instanced on one of the other faces.

Adding water elements

The water is a simple plane extruded and aligned so it intersects with the ground plane. The materials are quite simple, composed of two noise textures mixed and plugged into the normals input to give a sense of waves.

Add camera and adjust camera settings

For camera views, I typically move around the viewport until I find an angle that I like and the position the camera to the view by making sure that the camera I want to align is the currently active camera. The. In the viewport header, select View, align, align active camera to view.

For these kind of bird's eye views, I prefer to have the camera looking down in a way where we don't see the horizon line, so it makes the scene setup much easier and simpler. Also, we don't need to worry about the background being visible.

I usually set the camera focal length to about 30mm as the default 50mm is too narrow for architectural renderings. The Clip end distance may also need to be adjusted.

Add world settings HDRI with Lily Surface Scraper

The easiest way to light up a scene with with Blender 's sky texture. However, it doesn't have clouds so the light ends up looking too uniform. For this scene, let's use an HDRI background from polyhaven.com. Instead of manually downloading it, let's set it up more automatically with an add-on called Lily Surface Scraper.

Once it is installed, go to the world tab in the properties window, and you should see a new subtab

1. Click on the polyhaven button, and it will take you the website where you can choose a suitable HDRI.
2. Copy the URLs of the HDRI page that contains your preferred image
3. Back in Blender, in the Lily Surface Scraper subtab in the world settings, select “import from clipboard” after a few seconds you should see a popup that asks you at which resolution you would like to import the HDRI . I usually find 2k HDRIs suitable.

Now, if you go to the render preview in the viewport, with Cycles enabled, the scene should start to appear quite well You might need to rotate to HDRI to work with the camera view appropriately by going to the shader editor window, world subtab and changing the Z angle in the mapping node.

At the stage the base scene, the came angle, and the lighting are all set up so we are ready to add further details.

Gscatter grass scattering

Gscatter is a free add-on by the makers of Graswald that makes it easy to scatter grasses and other items. It contains a few grass pack presets that make it quite useful to get good looking grass with minimal effort. It also uses proxy-like low res geometry and has separate viewport and render densities so we do ts slow the viewport to a grind.

Under the hood, Gscatter is essentially a geometry nodes template so it leverages the geonodes instancing system, which is quite fast. Luckily we don't need to fiddle with the nodes when using Gscatter.

To add a system, click the book Library icon in the GScatter sideview tab and that opens a popup that shows the available presets.

Once we select a preset, let's adjust the density for the render while keeping the viewport density to quite low.

Gscatter has its own version of filters or modifiers that allows us to easily add effects to the scattering systems. Let's add camera culling so we scatter only what is visible. This is a great way to speed up the rendering.

In the camera cull options, select the camera I next, and manually adjust the frame to 30mm. Add a little buffer if a out 0.05 in order to take into account shadows that may be close to the camera view edges.

Let’s add another filter - proximity. We will use a few of these to make sure the grass doesn't interfere with the building and path objects. It quite straightforward - add the object and adjust the distance if necessary. I believe that this works with edges so for wide objects there may still be some grasses that show up in the middle.

I have added 4 proximity filters - for the building, the paths, the river, and the canal.

One system is now completely setup. Let's do a test render to make sure everything works well

Now we can copy the system and use another GScatter preset. When we copy the system, it retains all the existing modifiers so we don't need to redo them again. I usually add another system from the library to load the correct assets, and then in the copied system, change the geometry collection that contains the correct grass assets.

We can also try the painting effect and paint some vertices to adjust the pattern of the strength. Conveniently, it can be enabled and disabled fom within the filter in Gscatter.

Add trees

The trees come from this blendswap package . They are placed in a collection that’s used with a copy of a gscatter system duplicated from one of the other grass systems. The density is significantly reduced.

Add shrubs with geometry nodes curves

Now let's do a manual scatter based on a curve with shrubs brought in from this blendswap package containing bushes.

Add a spline, go into edit model and in the toolbar there is a new fairly new option to manual draw splines. It works quite well and follows the surfaces. In the tool settings, make sure you select to snap on to the surfaces instead of the 3d cursor.

After the curve or curves are drawn (as part of one curve object), let's add a geometry nodes modifier. Go into the geometry nodes editor, and add a resamplrncurve node. Change the type to length and set the distance to 1m. We should have plenty of points now so let's place the shrubs from a collection onto each point. Here is what the overall geometry nodes tree looks like.

The scene is complete. Time to make sure the render and world settings are correctly setup. Here is a few screenshots of the rendering settings that I have used.

Render Properties, World properties adjustments, and render output

For the most part, the render, output, and world properties are kept at their default values. I’ve reduced the max samples to 250, to get much faster render times with denoise enabled. Under color management, filmic, I’ve changed the look the Medium Contrast. Output properties are defaults, but in case you would like a higher res image, you the percentage can be adjusted from 100% to something like 250%. I’ve also adjust the strength of the HDRI background. We can adjust this settings in the world properties or on the shader editor.

Now, we are ready to render. Press F12 and wait until the render is ready. Make sure that you are not in render preview prior to rendering properly, as otherwise, both render processes tend to take up more RAM. Here is the raw output saved as jpg. It needs a bit of post processing.

Above is the raw render. I prefer to export a full float image that I then take into Affinity Photo for post processing.

Post-process EXR render in Affinity Photo

EXR import quite nicely in Affinity Photo. I typically use the Tone Mapping persona to make sure the base image looks correct. Here are the settings I used for to adjust the raw EXR file.

Further post processing with filters and overlays in Affinity Photo

I’ve used a few live effect layers to adjust the look further. They are Black and white filter, with 60% opacity, curves fulter, a ground fog, and a vignete. Here is how the composition is looking. Here is the final composition

The breakdown of the live filters used is as follows

Further resources

You’ve made it all the way to the end! Congratulations!

This file and many others that can help your learning process are available on https://patreon.com/uhstudio and https://uhstudio.gumroad.com

You might also be interested in some of my courses. Blender Architecture Masterclass offers the A-to-Zs for beginners on using Blender and the Blender for Architectural Design course is an intermediate course that showcases how to work well in edit mode and setting up a scene. I will be updating the Masterclass soon with a whole new module, and the price will increase, so if you are interested, now may be quite a good time to get it.