Shadows


https://forum.reallusion.com/Topic8942.aspx
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By stuckon3d - 16 Years Ago
Hello Forum,

I was reading a few posts about shadow problems and maybe I can clarify a few things for you guys regarding shadows in 2.5 VS 3.0, and please "Reallusion correct me if I'm wrong" because I'm not 100% sure since I have not read your internal coding for shadows. Tongue This is just a guestimate from someone that is familiar with 3d. ok?

As mentioned in previous posts, in IC 2.5 you have a shadow to start with, not only that, IC 2.5 had 3 types of shadows that you could play with. Drop shadows, wall shadows, and self-cast shadows. (BTW IC 3.1 has drop shadows and wall shadows back! Smile )

1) The Drop shadow which is there by default in 2.5, was a cheated shadow on an invisible ground plane. It was fast because it did not had to calculate on which object the light had to cast the shadow to, it was always the fake invisible ground plane, the down side was that you could not cast shadows on walls or other objects.

2) The wall shadow was like a 2d silhouette offset. again fast but it only looked good on walls but it looked fake on the ground.

3) And last but not least was the Self cast shadows, These shadows were very render intensive because it has to calculate not only the shadows for all the objects but also where it is going to cast the shadows to and deform them according to the shape of that object so that it looks correct. (however this type of shadow was only available for Nvidia card)

In IC3 you only have one type of shadows (self-cast shadows , however reallusion made it compatible with both ATI and Nvidia cards, which is a good thing Smile ) The downside to this is that these type of shadows are very gpu and cpu intensive.

Update: IC 3.1 has all three types of shadows again! Smile .

TIPS:

So what you are probable wondering is what can we do to make the workflow a little faster and less taxing on the hardware when it comes to shadows. Well... here are a few suggestions:

1) Set your desktop resolution lower if you have an old video card or machine. Just like a video game where you have to lower the screen resolution to get better frames per second, Iclone defaults to whatever desktop resolution you have at the moment. So if you have your desktop at 1920 x 1200 or more if you have dual monitors you might want to reduce the resolution of your monitor until you are happy with the frames per second you get inside iclone. Also you might want to turn swtich off your second monitor. All of these things will give you a huge performance increase.

2) Do not turn shadows on until after you finish your animation needs. Also remember that IC3 now allows you to turn objects to different types of shading as well as allowing you to turn objects on and off. Turning heavy objects into wireframe or off if you do not need to see them while you animate your character will increase your realtime playback.

3) Use spotlights to cast shadows only in the areas that are needed and use directional light and point lights as fill/ambient lights. Use the cone angle to control the area in which you want shadows to be casted. By doing this you can use smaller shadow map resolutions.

4) Turn off the cast shadows capabilities from all the objects that do not need to cast shadows. Sometimes you just want objects to receive shadows, not cast them. This will decrease the usage of gpu/cpu usage since the lights will have less objects to calculate shadows for.

5) Blocky shadows can be prevented if you follow the above advice. This happens when you are trying to cramm too many objects shadows in one shadow map/light. See this thread for more details.

https://forum.reallusion.com/Topic8742-82-1.aspx

6) Having the check mark for shadows next to the light on the scene manager is not enough, you have to scroll down on the edit light menu on screen right, and turn selfcast shadow on under shadow type.

7) In order to see a shadow on the ground you have to have a ground. In Ic 2.5 the drop shadow you have by default is being casted on a fake invisible ground. On IC3 you have to have an actual piece of geometry on the ground in order to see the shadows.

8) Shadow blur: A little goes along way in. When you turn shadow blur on it starts with 10 intensity, which is too high and it gives this ghosted trail effect, try 1 intensity and go from there. Blur also have different effects at different resolutions, blur 1 on 1k resolution looks very different from blur 1 from a 4k map. Why? because blur needs to work harder at lower resolutions in order to clean up the Aliasing/jaggies, so you need a higher intensity.

9) Bias: use it to fill/fix the shadow gap where two objects meet. This is a great little tool for fixing gaps that are created where two objects touch, sometime you have to go up a few numbers and sometime you need to go down. Do increments of 1 at a time and see the result, it does not take much to fix them. Smile

As soon as I get a little more free time at home, I will post some visual examples and some more tips on lighting.

I Hope this helped someone out there Smile

Stuckon3d

PS: I know I have a few typos in here but hey this is not a grammar class anyway. Tongue

Also, keep coming back to this thread if you see my name next to it, It means I added a new tip for ya Smile
By warlord720 - 16 Years Ago
Excellent information. Thanks!Cool
By jpiazzo_20090922180848311 - 16 Years Ago
Yes, great, thank you
By Galfridus - 16 Years Ago
Thanks stuckon3d

My icloning hasn`t really advanced to thinking of the "Shadows" stage yet but I`m always keen to learn from the forum.

I was really interested in your suggestion
Set your desktop resolution lower if you have an old video card or machine

I use an older PC with modest spec. If feel very lucky that so far ,I haven`t experienced some of the display problems other have had. I did have a high number of crashes initially but this seemed to improve when I reduced the default undo setting from 20 to 5.

I`ve just experimented with lowering my desktop resolution settings and can confirm that it does make a considerable difference to the frame rate playback for me. It will be much easier now to work on a scene with more that just a few props and a single character.

Really appreciate this excellent piece of advice.


By Scheffler - 16 Years Ago
This information was really helpful to me. Thank you!

Scheffler
By stuckon3d - 16 Years Ago
Hi guys,

Glad It helped. Smile

I'm almost done with my freelance project at home so I'll be able to dive into iclone3 100% and then the tips are going to get even better. Stay tuned. Cool
By stuckon3d - 16 Years Ago
Just added two more tips on shadow blur and bias.

Hope this helps,

Stuckon3d
By Peter (RL) - 16 Years Ago
An excellent explanation of shadows in iClone3. Thanks Stuckon3D. Smile

I'll pin this one. Smile

By stuckon3d - 16 Years Ago
Peter Edwards (9/5/2008)
An excellent explanation of shadows in iClone3. Thanks Stuckon3D. Smile

I'll pin this one. Smile


woow peter,
thanks Smile I'm working on some image examples as well, I hope to have them done by the end of the weekend, but dont hold me to it, I'm having too much fun with Iclone I might go off on a tangent and end up doing something else. Tongue
By anndee - 16 Years Ago
@stuckon3d: Thank you so much for your helpful posting in the shadow issue. I had problems with it, but now, after reading your excellent explanation, I understand to work with it.Smile
By stuckon3d - 16 Years Ago
Hello everyone,

I'm surprised that no one mentioned that drop shadows and wall shadows are back. Thanks REallusion, im sure you made a lot of people happy here. Smile



Also, I updated the shadow guide to make sure people know about it and what they do.



enjoy!



Stuckon3d
By DELETED2 - 15 Years Ago
This is excelling information especially about the Bias control.
I imagined there was a purpose but assumed it was for the sae of variance with different cards and rendering etc. I use it to make the shadows look how I personally want them. Smile
I didnt realise the technicality behind it.
A good educational post! Very grateful.