Rendering textures

[Gabriel Chan]

Hi all,

 

Taking a deeper dive into this rabbit hole of Renderworks.

 

Trying to figure out what causes the patchiness on Custom RW. Looking at the Custom RW render along the orange selection of the ceiling object, on top of the ambient occlusion effects, there are patches of white that make the whole ceiling look like mould is growing. I have included the Custom RW settings and lighting options as well. Nothing out of the ordinary here.

 

The Walls and Ceiling objects are basically using a White Paint RT, using Color for Color Shader and Plastic for Reflectivity Shader.

 

And just for reference, I have attached a Final Quality RW, that undesired effect is still there, though not as pronounced.

 

What gives?

 

Gabriel

Vectorworks 2020 Spotlight

[markdd]

This phenomenon happens when there is little or no light in a scene. You can never completely eradicate it, but you can make it reduce considerably by changing these settings

 

Indirect lighting: increase bounces to 4, then 16

Ambient lighting: increase a little 10-15%
 

Enable Anti Aliasing.

Increase quality to medium or high of:

Indirect lighting (controls the quality setting of bounce lighting)

Environmental lighting (controls quality of light from a Renderworks Background)

 

If you do each of these steps one at a time and check the render each time, you will see how the settings interact to give you the best results. 
 

Each time a setting is enabled or increased in value the render time will increase and this is the primary reason why these settings exist. So don’t be tempted to turn everything up to Max otherwise you will be rendering for hours and hours!!

 

[Gabriel Chan]

Hi Mark,

 

Thanks for the tips. On to experimenting!

 

Cheers,

 

Gabriel

[grant_PD]

You can look up some resources explaining GI calculations on the web.  Maxon's C4D help file has some pretty good articles about it, and that is the rendering engine you are basically using.  The  more you understand what is going on, the quicker you will be able to troubleshoot these types of situations.  

[Kevin K]

Gabriel

Interior renderings in VW are tricky, mainly because of configuring the lighting correctly.

What Grant and markdd pointed out are good thoughts on the subject, to be sure.

 

Cutting to the chase without getting overly complicated , for interior renderings here are a few suggestions:

1) Pretty much always use 16 bounces.  You can use 4, but if you zoom in close you will notice the difference.

2) You will note the screenshot below, pertaining to the basic settings that usually produce good results. May increase render time, but that is just the way the cookie crumbles :-) You will never get acceptable results using 'all low' quality. It is faster and will give you and idea how your scene is lit, etc, but rarely acceptable for the end quality of the rendering. I believe that is contributing to all that blotchiness you alluded to.

3) Be mindful of the dimension used for ambient occlusion.  You set it too high and you get very large shadows where the planes intersect.

4) * something that will also really help is to set up, on a design layer, 6 directional lights, with no shadows. One that points at the ceiling, one directly to the floor and one light each (4 total) with an elevation of 0, coming from each basic north, south east, west direction.

 

Because they are directional lights, even within an interior scene, those lights will affect each wall face.  Do be careful not to make them 100% bright.  That will produce too much light. Usually making them all slightly different between 30-40% brightness. This way you can easily customize how much light hits an interior surface (walls in your example rendering) You may need to play with the brightness levels a bit.

Then you can obviously add other directional lights at a slight angle that would use shadows to stream light through windows, etc.  those lights would want to be using brightness of between 80-100%, depending.   Hopefully all this makes sense. IF not I can send you a small file with the light setup I mentioned. This suggestion is of course for daytime interior renderings,  Night renderings are a whole different kettle of fish.

Anyway, experiment with these suggestions and see if you issues are somewhat mitigated.

 

So...as I prattle on. :-).  

 

This is what you get using the lighting suggestions mentioned above. I did reduce the resolution a bit to reduce file size.

I did use an HDRI hemispheric background in this rendering which you can see a bit of thru the windows, fyi.

 

 

 

[Kevin K]

In my haste, I forgot to mention...my bad.

Perhaps call that design layer 'Lighting Exterior' and do be sure to class each light, so that you can selectively use the lights you need for any particular rendering.

 

[Dave Donley]

Hello Gabriel Chan:

 

Is the only source of light the windows at the end of the room?

 

Since this is an interior the indirect lighting should be set to Interior.  Exterior is assuming an exterior scene and will not work well for this situation.

 

Also, by default the glass textures in VW have their indirect lighting options set to "Use Portal".  This is a technique that helps the renderer shoot rays at the windows where the only light is coming from.  If it is not on for your glazing texture already you can try that and it improves quality.

 

Indirect lighting quality will also help smooth this out, as well as adding more light than just the light finding its way through the windows.

[Dave Donley]

If you want to see what light is actually in the scene turn off ambient.  Also, ambient doesn't bounce around at all it will just flatten the look if you turn it up.  It will not correct anything.

 

Lights with no shadows on is non-physical and can easily cause the scene to become overlit, similar to turning ambient up which is also non-physical.

 

Note you can increase the brightness of directional light, heliodon, or sky backgrounds above 100%.

 

Try turning off ambient and indirect lighting to see what the renderer has to deal with.

[Gabriel Chan]

18 hours ago, Kevin K said:

something that will also really help is to set up, on a design layer, 6 directional lights, with no shadows. One that points at the ceiling, one directly to the floor and one light each (4 total) with an elevation of 0, coming from each basic north, south east, west direction.

 

Thanks Kevin!

 

That's a fabulous suggestion which I can see for sort of the finer controls . Will try that out over the weekend. Hoping to post some improved renderings.

[Gabriel Chan]

17 hours ago, Dave Donley said:

Hello Gabriel Chan:

 

Is the only source of light the windows at the end of the room?

 

Since this is an interior the indirect lighting should be set to Interior.  Exterior is assuming an exterior scene and will not work well for this situation.

 

Also, by default the glass textures in VW have their indirect lighting options set to "Use Portal".  This is a technique that helps the renderer shoot rays at the windows where the only light is coming from.  If it is not on for your glazing texture already you can try that and it improves quality.

 

Indirect lighting quality will also help smooth this out, as well as adding more light than just the light finding its way through the windows.

 

Hi Dave,

Currently there is only a Heliodon which I have set for Singapore, 6pm +8hrs GMT, where I am currently based.

 

I did not know there was a "Use Portal" option under textures. You do learn something new everyday with VWX, even after using it for 10 years!

 

Will definitely give that a go.

[Dave Donley]

The heliodon has a Sun Brightness field in the Obj Info palette shape pane, you can try brightness above 100%.  Also, the physical sky background that comes into your document when you choose Realistic Interior Fast has its brightness set to 300%, which will put more sky light into the room.  If your sky background is still set to 100% brightness try cranking it up.  HTH

 

[Gabriel Chan]

It's the weekend! And I finally got down to doing some tests. Compiling results over here that hopefully might become a useful resource.

 

What I've done is start from zero lighting sources, and progressively added them, taking note of the rendering times. Then with each permutation, one variable is altered so that I get to see the difference in quality and render times based on that variable. I place an emoji 👈 so that it's easier to pick out what the permutation is from the previous test.

As a reference, I am using an iMac Retina 5K, 27 inch, 2017 workstation, 4.2Ghz Core i7, with 24MB DDR4 RAM and Radeon Pro 580 8 Gb Graphics.

 

Test 1: No Ambient | No Environment Lighting | Render time: 2m28s

Options

Anti-Aliasing, Shadows, Textures and Colours checked. Additional options under textures were all left unselected.

Quality

All Low except Indirect Lighting, set to High.

Max Reflections: 3

Lighting Options

Indirect Lighting: Interior 16 bounces

Ambient Info: Off

Environment Lighting: None

Remarks: Scene is full dark with zero sources of lighting. Interesting that reflective surfaces do render reflection even without light sources present. Also note the image prop of a hanging plant is self illuminating, perhaps suggesting it does not interact with lighting?

 

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Test 2: No Ambient | Physical Sky Interior Renderworks Background | Render time: 3m06s

Options

Anti-Aliasing, Shadows, Textures and Colours checked. Additional options under textures were all left unselected.

Quality

All Low except Indirect Lighting, set to High.

Max Reflections: 3

Lighting Options

Indirect Lighting: Interior 16 bounces

Ambient Info: Off

Environment Lighting: Physical Sky Interior👈

Remarks: Adding Environment Lighting immediately adds a lot of information to the scene. The slight glow at the end of the room adds some depth to the scene and suggests that's where most of the light is filtering in from. Indirect Lighting Texture Options under Glass RT set to enable portal. Minimal impact to render times.

 

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Test 3: Ambient On at 25% | No Environment Lighting | Render time: 2m33s

Options

Anti-Aliasing, Shadows, Textures and Colours checked. Additional options under textures were all left unselected.

Quality

All Low except Indirect Lighting, set to High.

Max Reflections: 3

Lighting Options

Indirect Lighting: Interior 16 bounces

Ambient Info: On 👈 

Brightness: 25%

Ambient Occlusion strength 50% / Size 100

Environment Lighting: None👈

Remarks: Comparing this with Test 1, the only change will be turning on Ambient lighting at 25%. Compared with Test 1, again a lot more information in the scene, but noticeable a lack of depth when compared to Test 2. Notice the False ceiling on the right blending directly into the main ceiling itself. Additional rendering time (5 secs) is actually negligible when compared to Test 1, and it is in fact faster than Test 2. May consider this as a more detailed render with all light sources as opposed to OpenGL (which has a limit of 8 lights).

 

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Test 4: Ambient On at 25% | Physical Sky Interior Renderworks Background | Render time: 3m11s

Options

Anti-Aliasing, Shadows, Textures and Colours checked. Additional options under textures were all left unselected.

Quality

All Low except Indirect Lighting, set to High.

Max Reflections: 3

Lighting Options

Indirect Lighting: Interior 16 bounces

Ambient Info: On 👈 

Brightness: 25%

Ambient Occlusion strength 50% / Size 100

Environment Lighting: Physical Sky Interior👈

Remarks: Now we start combining two lighting sources, Ambient and Environment lighting, and the scene again looks better than Test 2 or 3 where only one light source was defined, as we get more information and depth as well. Render time is excellent at 3m11s.

 

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Test 5: Ambient On at 25% | Physical Sky Interior Renderworks Background | 01 x Line Light | Render time: 4m19s

Options

Anti-Aliasing, Shadows, Textures and Colours checked. Additional options under textures were all left unselected.

Quality

All Low except Indirect Lighting, set to High.

Max Reflections: 3

Lighting Options

Indirect Lighting: Interior 16 bounces

Ambient Info: On  

Brightness: 25%

Ambient Occlusion strength 50% / Size 100

Environment Lighting: Physical Sky Interior

Additional Light source in the scene

01 x Line Light at 5000 lumens with Cast Shadows and Soft Shadows checked👈

Remarks: Adding a third light source into the scene, we get more depth information of the false ceiling with respect to the main ceiling. Overall the scene looks slightly better lit than Test 4. Additional render time of 1min for 1 light source suggests that the light sources do start making renders more complicated. There is some splotchiness where the line light grazes the ceiling.

 

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Test 6: Ambient On at 25% | Physical Sky Interior Renderworks Background | 01 x Line Light | 03 x Spot Light | Render time: 4m28s

Options

Anti-Aliasing, Shadows, Textures and Colours checked. Additional options under textures were all left unselected.

Quality

All Low except Indirect Lighting, set to High.

Max Reflections: 3

Lighting Options

Indirect Lighting: Interior 16 bounces

Ambient Info: On  

Brightness: 25%

Ambient Occlusion strength 50% / Size 100

Environment Lighting: Physical Sky Interior

Additional Light source in the scene

01 x Line Light at 5000 lumens with Cast Shadows and Soft Shadows checked

03 x Spot Light over kitchen counter at 4000 lumens with Cast Shadows and Soft Shadows checked  👈 

Remarks: Adding three additional spot lights into the scene, the scene looks better lit than Test 5, with the pendant lights defining a nicely lit space around the kitchen counter. Interestingly, the additional render time of 9s for these 3 spot lights suggests that not that much computational resources are required as compared to a Line Light source. This 9s also is for computing the additional geometry of the lamp shades, so really not much load added on to the renderer. Notice also that the hemispherical shape of the lamp shades have a jagged edge to it, which likely suggests a higher Anti-Aliasing Quality is required (currently set to low). Also note the underside of the lamp shade is dull, and is missing a quality of a glow usually present. There is some scalloping of the lights on the wall on the right where the 2 bar stools are, and the contrast between light and shadows seem a bit too harsh.

 

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Test 7: Ambient On at 25% | Physical Sky Interior Renderworks Background | 01 x Line Light | 03 x Spot Light | Render time: 4m31s

Options

Anti-Aliasing, Shadows, Textures and Colours checked. Additional options under textures were all left unselected.

Quality

All Low except Indirect Lighting, set to High.

Max Reflections: 3

Lighting Options

Indirect Lighting: Interior 16 bounces

Ambient Info: On  

Brightness: 25%

Ambient Occlusion strength 50% / Size 100

Environment Lighting: Physical Sky Interior

Additional Light source in the scene

01 x Line Light at 5000 lumens with Cast Shadows and Soft Shadows checked

03 x Spot Light over kitchen counter at 4000 lumens with Cast Shadows and Soft Shadows checked. Distance Falloff set to Realistic 👈  (previously set to None)

Remarks: Compared to Test 6, we now see a nice glow on the underside of the pendant lamp shade. The scalloping of lights on the wall on the right is still present. It is an improvement from the previous test, where the contrast between light and shadows are now a little more subdued, although I would still consider it unrealistic. Starting to notice some leakage of lights from the Line Light source which does not look ideal.

 

Edited December 13, 2020 by Gabriel Chan

[Gabriel Chan]

Test 8: Ambient On at 25% | Anti Aliasing High | Physical Sky Interior Renderworks Background | 01 x Line Light | 03 x Spot Light | Render time: 12m14s

Options

Anti-Aliasing, Shadows, Textures and Colours checked. Additional options under textures were all left unselected.

Quality

All Low except Indirect Lighting and Anti Aliasing👈, set to High.

Max Reflections: 3

Lighting Options

Indirect Lighting: Interior 16 bounces

Ambient Info: On  

Brightness: 25%

Ambient Occlusion strength 50% / Size 100

Environment Lighting: Physical Sky Interior

Additional Light source in the scene

01 x Line Light at 5000 lumens with Cast Shadows and Soft Shadows checked

03 x Spot Light over kitchen counter at 4000 lumens with Cast Shadows and Soft Shadows checked. Distance Falloff set to Realistic

Remarks: Where in Test 7, the contrast between shadows and light would be too harsh to be considered realistic, Anti Aliasing seems to smoothen that out into something acceptable for presentation. I suspect the round and curve elements for Spot Lights and the pendant lamp shades may have benefited from a higher Anti Alias setting. Render time take a big hit at 12m14s however, which is almost 3 times the render time for Test 7. Perhaps there is a need to weigh the options between render times and quality when there are round/spherical elements in the scene.

 

[grant_PD]

Very nice tests, and a good way to learn the various settings for rendering output.  Some things to consider:

Ambient occlusion will create contact shadows where things meet, and combined with GI might obscure the effects of GI.  GI sort of works in the reverse, bouncing light around to fill in areas, leaving behind those contact shadows.  

 

Is the overall look of the scene what you are intending for the final output?  It seems very underlit to my eye.  If those are the only light sources you are intending on using, would you in a real world increase the exposure times for your shot to get in some more information to your shot?  I adjusted the levels in photoshop and got this just out a screenshot. of your render.

 

[Kevin K]

Gabriel

As Grant pointed out, messing with the various settings is really good practice, to be sure.

Since I do a LOT of rendering, you gotta let go of trying to use the Low modified settings :-). Make life wayyy to complicated.

 

Question: is this supposed to be an interior daytime rendering?  Point being, normally in a daytime condition you dont have a bunch of interior lights casting shadows all over the place. Unless of course you want that look.

I dont think you used my suggestion of setting up the various directional lights to be able to quickly and easily get some decent lighting for your rendering.

 

Is the file huge?  IF there is a way you could post it, perhaps through a dropbox link or WE Send I would love to get your file and. demonstrate some lighting options to get the rendering looking really nice.

You call on that.

[Kevin K]

Grant, nice job tweaking in Photoshop :-)

 

Don't you think that the ambient occlusion is set a bit high though?  

Like where the walls meet the ceiling on the left side of the image?

 

What is your opinion?

[Gabriel Chan]

40 minutes ago, Kevin K said:

Gabriel

As Grant pointed out, messing with the various settings is really good practice, to be sure.

Since I do a LOT of rendering, you gotta let go of trying to use the Low modified settings :-). Make life wayyy to complicated.

 

Question: is this supposed to be an interior daytime rendering?  Point being, normally in a daytime condition you dont have a bunch of interior lights casting shadows all over the place. Unless of course you want that look.

I dont think you used my suggestion of setting up the various directional lights to be able to quickly and easily get some decent lighting for your rendering.

 

Is the file huge?  IF there is a way you could post it, perhaps through a dropbox link or WE Send I would love to get your file and. demonstrate some lighting options to get the rendering looking really nice.

You call on that.

 

Hi Kevin, Grant,

 

Thanks for all the input. This is definitely still a work in progress. It was as much as I'd give my weekend to do all the tests so far. I'm likening these tests to a marathon that I will execute over a few weeks instead of a short sprint. Hoping this will be a LONG post eventually.

 

Low settings are not the way to go, but it is a great way to understand what settings affect the which aspects of the render, without having to wait half an hour between each render.

 

I have yet to experiment with the various directional lights - will do that in the next series of tests. I will probably compare what these directional lights do VS Ambient lighting. The ambient occlusion could definitely come down slightly.

 

@Kevin K PMed you

[Kevin K]

I realize all this for you is a work in progress.  

Don't get me wrong, what you are doing , experimenting and checking out the various settings is definitely time well spent!

 

[Gabriel Chan]

Cheers Kevin!

 

I realised haven't given much thought to whether this would be a daytime scene or not. I suppose that means I will have to expand my experiment parameters and do both!

Edited December 13, 2020 by Gabriel Chan

[Kevin K]

Indeed....night renders require a bit more work....and interior lighting. 

But, that said, the results can be pretty satisfying.

[Tom W.]

On 12/7/2020 at 6:08 PM, Dave Donley said:

by default the glass textures in VW have their indirect lighting options set to "Use Portal". 

 

Not the 'Glass Clear RT' texture I've always used... My version now has this setting enabled!