Physically based engine in 3D window

[Camila Cuevas]

With the physically based 3D engine in Archicad, you can display more realistic visualizations directly in the 3D window, without having to separately generate a rendered image.

• Physically Based Rendering Contours
• Procedural Sky
• Improved Ambient Occlusion
• Shadow Mapping
• Automatic Exposure Control and Bloom

Standard 3D window display without physically based 3D engine	Experimental feature enabled: physically based 3D engine

To use the physically based 3D engine:

1. Select a 3D Style with Hardware Acceleration and Shadows enabled in the 3D window.

2. Open the Work Environment settings under Options > Work Environment > More Options...

3. Expand the Experimental Features tab and check the box next to Enable Physically Based 3D Engine.

 NOTE:  As this is still an experimental feature, avoid having it active at all times. Instead create a separate Work Environment Profile to quickly and easily switch between the standard 3D display and the experimental Physically Based 3D Engine. This allows you to use the physically based engine for presentations and then return to the standard profile for regular modeling in Archicad.

Physically Based Rendering Contours

3D Style contours are now supported when Physically Based Rendering is active, allowing for clearer edge definition in your 3D views.

NOTE: This feature is available starting with Archicad 29.

Physically based 3D rendering without contours	Physically based 3D rendering with contours

To activate them, go to View > 3D View Mode > 3D Styles... and enable Show Contours for the current 3D style, under the Contours tab. You can adjust contour line thickness using the slider under Contours.

  NOTE: If contours are enabled, these will also be displayed on 2D billboards shown in 3D. You can make the contours of 2D billboards invisible with a Graphic Override using the Hide Model Contours option.

Procedural Sky

The procedural sky simulates atmospheric light scattering effects to create a physically based sky dome. Surfaces in shadow reflect diffuse light generated by the sky. When the Sun Position is adjusted, the dynamic skybox also changes according to the set date, time, or angle.

Sun position: Vertical 35°, Horizontal 60°	Sun position: Vertical 15°, Horizontal 80°

This effect is also reflected in the glass surfaces of façades, windows, and doors.

This effect is also visible in the moving shadows of skylights.

NOTE: The dynamic skybox is also available in the BIMx Viewer. For more information on the dynamic skybox in BIMx Viewer, see here.

Improved Ambient Occlusion

The new algorithm uses low-discrepancy sequences to distribute samples more efficiently, removing artifacts in areas with low sampling.

Ambient Occlusion – before	Ambient Occlusion – after

Shadow Mapping

Shadow mapping delivers much faster results than previously used shadow volumes. Additional advantages of shadow mapping include soft shadow edges and perspective warping—objects closer to the camera occupy more space in the shadow map, which nearly eliminates perspective aliasing.

Shadow volume	Shadow mapping with soft shadows

Thus, shadows from 2D elements (so-called billboards) now follow the actual cutout shape.

Automatic Exposure Control and Bloom

The tone mapper now (semi-)automatically adjusts exposure, behaving similarly to real cameras. Areas with high luminance show bloom, replicating a glare effect. Exposure adaptation becomes more noticeable in 3D walkthrough mode, as it introduces a half-second delay. The bloom effect varies with the camera position in the scene.

Exposure is automatically adjusted	Bloom effect