Revit Cloud Rendering improvements

We are happy to announce the significant improvements made to the Autodesk Revit Cloud Rendering, which have been released on Dec 9th, 2018. 

The new version of our cloud rendering engine improves on quality and fixes old issues. As many old projects might have been tuned to look right with the old version of the engine, you will notice that new rendering will look different.

As the new version is more strictly photoreal and relies on correct inputs (especially materials settings), some adjustment to old projects might be necessary to get the best results.

We suggest using the new Revit material types (especially for mirrors, metals, and glazing) and to follow the guidelines reported below whenever possible.

 

Feature Improvement

1. Quality improvements with new rendering engine

• There are significant improvements in quality in some scenes, both standard and final. A newly added denoising algorithm can often produce noise-free renderings in cases where the previous algorithm would show noise even in "final" quality.

Standard Quality Before	Standard Quality After

 

2. Materials Appearance Consistency with Revit in-product

• The cloud renderer used to have a different implementation of legacy materials (which originate from Mental Ray) than the in-product Revit renderer. This is now fixed, and both in-product and cloud are based on the same shader codebase. Any remaining mismatches are likely to be due to data translation issues, not shader differences; please report them as bugs.

Before	After	In Product

 

• If the new physically based Revit materials are used instead (Revit 2019 or later)， local and cloud rendering should always match.
• Documentation about the new physically based materials is available here:
  • Full documentation
  • Introductory document

 

3. Lights enhancement

• The previous rendering engine had a corner darkening issue. In new renderings, this problem is fixed.

Before	After

 

• The previous rendering engine had problems with area lighting close to other surface, causing light splotches. This problem is gone now.

Before	After

• Note, several bugs have been fixed in the cloud renderer that have not yet been ported back to Revit. This will still lead to some differences and will be fixed in a later version of Revit. Until then, the cloud result should be treated as correct.

 

4. Water Wave Height

• Old water materials will have an incorrect Wave Height because their settings were unitless. Exaggerated water surface can be easily fixed editing the material. There is no specific rule on how much the Wave Height value should be lowered. Set it to what looks right for your scene.

Default wave height	Reduced wave height

 

5. Scenes with no lights

• Rendering a scene with no lights (closed room with no artificial lights) now renders a black image instead of flat colors.

Before	After

 

6. Panoramas

• Panoramas no longer support the solid color background option, but you can download a panorama image with Alpha channel and add the desired solid color background in an image editing application.

 

7. Emissive decals

• In the meantime, emissive images like monitors can be achieved using the new Revit physically based opaque material. This guarantees that they are physically accurate and much more realistic.

Before	After	With Opaque emissive material

8. IES web orientation

• We fixed an issue that was causing IES webs to be rotated in the wrong direction. Be aware that re-rendering old files you might get different lighting.

 

9. Missing textures behavior

• Missing textures will now be replaced by a black color instead of white. The Revit exporter, before uploading the processed scene for rendering, warns you about the textures that were not found. Make sure you check the list and understand that materials using those textures will not be able to use them.
• When rendering locally, the missing texture behavior might differ.

 

10. Performance

• The new service will show a significant increase in performance for rendering jobs with many frames (especially solar study, stereo panorama). These frames are now distributed to separate cloud nodes for rendering, instead of rendering sequentially on a single node.

 

11. New Post Processing tool

• A new image post-processing widget replaces Exposure Adjustment and adds several features.

Old UI	New UI

• A few preset curves are provided, providing a simple way to switch between looks: linear, neutral, mild and vivid. A custom curve can still be chosen, by manually setting the highlights, midtones and shadows parameters from the previous version of the widget.

Linear	Neutral	Mild	Vivid

 

• A new bloom effect is very useful to achieve additional realism, by simulating low-frequency light leaking between pixels, an effect common in real cameras and human eyes. The true brightness of over-exposed areas (e.g. windows, light sources and specular highlights) can be made more obvious using this effect.

 

• Color correction and color preservation can now be turned on and off explicitly. Keeping them off is recommended and often looks better unless a specific look is desired.
• We have also improved the look of the automatic (“Advanced”) exposure.

 

12. Viewer changes for multi-frames renderings

• When view the in-progress rendering of multi-frames rendering like Solar Study and Turntable rendering, the viewer supports to show progressive rendering for each frame.

Old UI	New UI

 

13. Download menu for solar study

• New option to enable download of Solar study as video.

Old UI	New UI

 

Limitations and Best Practices

 

14. Overlapping geometry

• If you see circular artifacts on surfaces, it’s probably because there is overlapping geometry. Make sure your walls, ceilings, floors, glazing is not duplicated or intersecting. When overlapping geometry occurs, the renderer can’t consistently pick the material of one or the other surface.

 

15. Coincident lights geometry

• Placing a light shape coincident to a light fixture geometry can cause artifacts or missing light emission or visibility. Make sure you separate the light a bit to avoid this issue.
• Other issues could arise if the light is put behind a translucent, frosted, or semi-transparent material, as the renderer will have a hard time resolving paths to the light. Place the light in front and use a lightly emissive material for the shade behind it.

 

16. Point lights visible in reflections

• If you use point lights throughout your scene to add a certain amount of ambient light, those lights will appear in reflections on mirrors and glass surfaces.
• We suggest removing those lights and add real lights, as the renderer is strictly photoreal. After rendering you can adjust the exposure to bring up the mid-tones and brighten up the scene.

Before	After

 

17. Panorama and Stereo Panorama rendering

• The progressive rendering preview will not show all frames always. It will show the frames that are in progress or completed. If the advanced exposure has been set, the progressive preview will have different exposure with final one.

Progressive Preview

One side of the cube rendering is still in progress, while the other two are complete.

 

Progressive Preview (Advanced exposure)	Final (Advanced exposure)
Each side of the cube rendering has a slightly different exposure.	In the final rendering, the exposure is unified.