barkest Posted April 28, 2017 Share Posted April 28, 2017 (edited) My default position has always been that soft shadows take longer to render than hard shadows. In Cinema 4D its the opposite way around. Have I been getting it wrong in VW? Quote Rendering hard or area shadows is much more computationally intensive thanks Edited April 28, 2017 by barkest Quote Link to comment
Vectorworks, Inc Employee Luis M Ruiz Posted April 28, 2017 Vectorworks, Inc Employee Share Posted April 28, 2017 I'd question this, would hard shadows make my interior renderings more accurate? In many of my scenes I have a combination of both. If there is sun light present hard shadows it is, if it comes from a distance light bulb then vanishing shadows help. Does this take longer? I think I'll run a test on this one. Quote Link to comment
grant_PD Posted April 28, 2017 Share Posted April 28, 2017 3 types of shadowing: Hard=Raytraced, which takes a long time Shadow mapping=depending on the sample size, can be very fast Area shadows=takes a long time Hard to know what VW means by "soft shadows." Are they shadow mapped or area shadows? Quote Link to comment
barkest Posted April 28, 2017 Author Share Posted April 28, 2017 2 hours ago, grant_PD said: Hard to know what VW means by "soft shadows." Are they shadow mapped or area shadows? Looking at the times I would think area shadows, happy to be corrected Quote Link to comment
grant_PD Posted April 28, 2017 Share Posted April 28, 2017 I would guess. Odd that VW does not allow for shadow mapping. It's been around for a while. Quote Link to comment
barkest Posted April 28, 2017 Author Share Posted April 28, 2017 Maybe Luis can come up with a nice long tech breakdown of shadows Quote Link to comment
Pat Stanford Posted April 28, 2017 Share Posted April 28, 2017 3 hours ago, Luis M Ruiz said: I think I'll run a test on this one. Luis, Perfect time to try that thing we talked about last week. Let me know. Pat Quote Link to comment
grant_PD Posted April 28, 2017 Share Posted April 28, 2017 I love it when the A-Team gets involved. Quote Link to comment
zoomer Posted May 1, 2017 Share Posted May 1, 2017 On 28.4.2017 at 2:41 PM, grant_PD said: 3 types of shadowing: Hard=Raytraced, which takes a long time Shadow mapping=depending on the sample size, can be very fast Area shadows=takes a long time Hard to know what VW means by "soft shadows." Are they shadow mapped or area shadows? You mentioned the shadow types : Mapping = fast + inaccurate Raytraced = not slow + very accurate, but unrealistic in a way that we do not have real light sources with zero size Area = slowest + accurate Shadow Mapping is soft to very soft, depending on Map Resolution. The problem is that softness is independent from distance. A pole's shadow will be a soft at its base as for its top. It is a bit like the 2017 drop shadow effect. Area Shadows softness is dependent on distance from the object casting to the surface, to the surface receiving the shadow. As larger the distance, the larger the softness area > accurate. It works a bit like Ray Traced Shadows, just that you need to trace more than 1 Ray (Samples), from different directions and finally interpolate in some way. That is why that shadow type ist harder to compute and so slower. So if you watch those soft shadows from VW, if short shadows are sharper and longer shadows more blurry, those will be true and slow area shadows. Quote Link to comment
barkest Posted May 1, 2017 Author Share Posted May 1, 2017 41 minutes ago, zoomer said: As larger the distance, the larger the softness area > accurate. My understanding is that the further away the harder the shadow (the sun), the closer the softer the shadow. In addition its not just down to distance it is also affected by the size of the area light. Larger area lights will give softer shadows. Quote Link to comment
zoomer Posted May 1, 2017 Share Posted May 1, 2017 Yes, As larger the Light - the softer the Shadow As farer the distance of the Light to the shadow casting Object - the sharper the Shadow And, As farer the distance the Shadow Rays have to travel from the shadow casting Object to the Object receiving that Shadow - the softer the Shadow. You can take your desktop lamp at an 45° angle and shine on a pencil that you put vertically on your desk. Where the pen meets the table (=short distance) the shadow will be quite sharp, while the shadow of the pen top, that has a larger distance to travel is much softer. Quote Link to comment
zoomer Posted May 1, 2017 Share Posted May 1, 2017 Shadow Map (blurry everywhere) : Raytraced Shadow (sharp everywhere) : Area Shadow (sharp where near, blurry where far) : Quote Link to comment
grant_PD Posted May 1, 2017 Share Posted May 1, 2017 I would prefer that VW incorporate shadow mapping as well. Area shadows (time) vs raytracing (quality) seems like a lose/lose to me. Quote Link to comment
Vectorworks, Inc Employee Luis M Ruiz Posted May 1, 2017 Vectorworks, Inc Employee Share Posted May 1, 2017 On 4/28/2017 at 10:52 AM, Pat Stanford said: Luis, Perfect time to try that thing we talked about last week. Let me know. Pat I am on it.... Quote Link to comment
Vectorworks, Inc Employee Luis M Ruiz Posted May 3, 2017 Vectorworks, Inc Employee Share Posted May 3, 2017 Sorry for the delay, I was away at AIA Orlando booth running 3d and rendering demos, now, we are back and I have something to share. By using Pat's time script I was able to compare the time it takes to render four viewports with the same properties but different lights configurations and two rendering styles. To my surprise, sharp shadows with no ambience lights take very little time compared to a light source with soft shadows. Now, when we get close to produce a better quality rendering we add some environment light and a number of light bounces, here is where the time to my taste is irrelevant, the waiting period was minor. Here are my notes: 1 Quote Link to comment
barkest Posted May 3, 2017 Author Share Posted May 3, 2017 In the second example it looks like an area shadow and the timing supports that. Quote Link to comment
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