ArchViz from V-Ray to Cycles (with tips)

In this series will be doing different types of high quality architectural scenes from V-Ray(3ds Max) into Cycles with tips and comments about the problems and solutions in converting V-Ray to Cycles. The series includes a collection examples from ArchViz scenes in V-Ray(3dsMax) from Evermotion, and others as basis to convert to Cycles. I used my own custom script for converting V-Ray scenes with the “MaxToBlender” addon. It is not required and see below for other options.

The workflow for exporting and converting from V-Ray to Cycles includes a number of parts:

Export:

  1. Export directly from 3dsMax by first converting the V-Ray materials and maps to standard 3ds Max. After can use directly FBX export or BMAX Connector link BMAX.
  2. Use MaxToBlender addon see link MaxToBlender. The exporter part works fine. The importer part of the addon into Blender has a lot issues. I re-wrote this script to handle properly all V-Ray lights(IES, HDRI and others), material for V-Ray 3x,4x, and 5, textures, PBR. The conversion works for production type scenes. See link Custom MaxToBlender script.

FBX:

  1. Make sure to enable the option “Include->Geometry->Preserve Instances” will export all instances from 3ds Max.
  2. 3ds Max defaults unit is centimeter and Blender is in meter. With default settings once the scale is match properly all objects have the will have the correct dimension, but the scale transformation will be divide by hundred. Given all objects a scale of 0.01 instead of 1.0. Their is a hack by increasing the object size by 100 and having scene unit 0.01, but is not ideal.
  3. Proper scale fix in the 3ds Max FBX exporter change the option “Include->Advanced Options->Axis Conversion” to Z-up". In the Blender FBX importer enable “Apply Transform” and change the “Manual Orientation” to axis_forward=‘Y’ and axis_up=‘Z’.
  4. Another available importer for FBX is the “Better FBX Importer/Exporter” addon see link Better FBX. It has more advance features specially for animation, for ArchViz it has number of drawbacks compare to Blender importer. It is much slower at least 5x, the “Apply Transform” option is not available and material imports is not as good e.g. the PBR materials from Evermotion FBX scenes did work properly.

Scene:

  1. V-Ray cameras can use “Auto Tilt Correction”. Too match this feature In Cycles change camera X rotation to 90 degrees and adjust the camera option “Shift-Y” until proper view angle is achieve. This will maintain perpendicular perspective vertical lines.
  2. GPU memory will be an issue for card with 8GB or less with many scenes with hundred’s of 4K textures. Two options are first under the render options “Simplify” enable it and set the “Texture Limit” to “1024”. It will resize the textures before rendering. The second option is to create a copy directory of all the textures and in the Windows file explorer right click on the title bar and add a “Dimension” column. Sort and select all the textures 4K and above and drag and drop in to “ImBatch” application and run a resize task in place. “ImBatch” application is free link ImBatch. Second option has the advantage being able to select which textures not to resize for render quality and much faster loading time in Blender, since Blender does not have to resize before they are used.

Lights:

  1. HDRI’s will need to adjust the rotation to match 3dsMax.
  2. IES will need to create the proper node setup.
  3. The rest of the lights make sure to match the location, direction and size.
  4. Light intensity will not match Cycles light and need to adjust properly.

Materials:

  1. V-Ray can use high “Fresnel IOR” above 10 for metallic surfaces.
  2. Glass windows usually won’t work correctly. Need setup thin glass material in Cycles.
  3. Need baked textures with more complex node setup (falloff, noise, color correction, etc). MaxToBlender addon usually handles this automatically.

Other:

  1. ArchViz rendering can take a long time to improve Cycles performance see my link up to 2X rendering improvement. If budget allows K-Cycles is option see link:
  1. Denoiser for low noise scenes “NLM” denoiser is the best for sharper textures. For medium scene type noise “Optix” is great and the fastest. For scene type with high noise “OpenImageDenoise” has the best results, but it softness the textures. To get sharper image denoiser I can recommend “SuperImageDenoiser 2.0” see link SuperImageDenoiser. The Super/High Denoiser nodes has the transmission(Glass) “Denoising Normal” and “Denoising Albedo” disconnect. Connect them manually for best transmission quality.
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The Evermotion volume 49 scene 1.

Notice that V-Ray GPU had problem with too many 2d-displacement, so they had to be disable causing the blurry background. In Cycles I used the NLM denoiser for a nice sharp background texture.

V-Ray GPU raw output 1min 21sec.

Cycles raw output 37 sec.

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The Evermotion volume 50 scene 1.

This scene has over 800+ texture, 200+ materials and 100+ lights. The import and export took about 1 minute each. Quite a few lights had to be tweak and a few material adjustments. V-Ray GPU courtyard lighting is brighter than it should be compare to V-Ray CPU due to glass transmission differences.

V-Ray Camera 1 GPU raw output 1min 32sec for :


Cycles Camera 1 raw output at 2000 samples took 2min 08 sec:

Cycles Camera 2 raw output at 2000 samples took 1min 55 sec:

Cycles Camera 3 raw output at 2000 samples took 1min 57 sec:

Cycles Camera 4 raw output at 2000 samples took 2min 01 sec:

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The Evermotion volume 51 scene 2.

This scene has over 850+ texture and 300+ materials. The import and export took about 1 minute each. Adjusted the main lights and a few material adjustments.

V-Ray Camera 1 GPU raw output 4min 32sec for :

Cycles Camera 1 raw output at 2000 samples took 3min 35 sec:

Cycles Camera 2 raw output at 2000 samples took 3min 13 sec:

Cycles Camera 3 raw output at 2000 samples took 3min 32 sec:

Cycles Camera 4 raw output at 2000 samples took 3min 10 sec:

Cycles Camera 5 raw output at 2000 samples took 3min 05 sec:

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The Evermotion volume 54 scene 3.

This scene has over 750+ texture and 200+ materials. The import and export took about 1 minute each. Adjusted the main lights and a few material adjustments specially the pool water. The scene could not render properly with the current version of V-Ray, so I used the V-Ray post process image for reference

V-Ray Camera 1 post process image:

Cycles Camera 1 raw output at 2000 samples took 3min 50 sec:

Cycles Camera 2 raw output at 2000 samples took 3min 32 sec:

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