Making of the Oak Tree

Today’s architectural visualization industry often relays on stock libraries which lead the market to a uniform aesthetical style. Greenery is one of the most frequently acquired assets and there are only a few high-quality suppliers. In this short tutorial, I will give you an idea of how we alter tree libraries to add more uniqueness and personal touch to our visualizations.

In this article, I will explain how to enhance the GrowFX tree library on the example of MaxTree vol. 12. As a base software, we use the archviz standard 3ds max 2020 and Corona Renderer 5.

Let’s start with a basic scene lit with HDRI. The HDRI map comes from the VizPeople collection and was tweaked in Photoshop to get the desired balance between sun and sky exposure. This operation will be described with more details in one of the further blog posts. With lighting and camera set up for tests now, we can move to our tree.

References
As a first step, we should collect relevant reference images to get the right direction. A bunch of photos of the oak trees with acorns will be sufficient help. The basic model contains neither seeds nor detailed leaves. Real oak leaves are a bit wavier.

Leaves
We need to edit the GrowFX source file and alter some parameters to receive a cavity in the midrib and wavy blade.

Tip: A good practice it to hide currently unedited parts of the GFX model and make adjustments on a copy with reduced size and complexity as each iteration may take over a minute.

Photoscanned acorn
Distribution of acorns requires stems as a source points. The key thing is to set proper values in Vector Direction: Strength and Path parameters: Steps

The 3d scan of the acorn comes from CGTrader and it needs some mesh and the shader alterations.

1 – UVW Map displacement wasn’t placed evenly on the seed and editing the mesh was quicker than Unwrapping or fixing all PBR maps
2 – the base part we didn’t need
3 – repainted diffuse channel to get rid of the dark splotches
4 -added extra detail to the model to bring out the cupule and the nut

Final touches
Manually placed acorn

All acorns were generated randomly by GrowFX and we lost some control over the composition. As we see most of the nuts in the focus area on the right are oriented outwards. Such layout gives a feeling that our look is directed out of the camera frame and now it needs some intervention. We have added the element that brings our sight back. The oppositely oriented acorn returns the balance in the composition.

Camera settings

To get more control over the depth of field in the image we used ‘Use simple (EV)’ mode. The lower f-stop number is the more explicit effect we get.

To simulate chromatic aberration we used color bitmap which is available in the Corona Renderer documentation site.

Before

… and After