Ogre Soft Shadows Demo

[Bluntspoon]

Rapidshare has an error, when i try and then takes you round in circles, The other makes you pay and the other also has an error.
May you please give a downloadable link, looks great and would like to try it out.

[jacmoe]

Rapidshare works just fine.

[Azgur]

Rapidshare has an error, when i try and then takes you round in circles, The other makes you pay and the other also has an error.
May you please give a downloadable link, looks great and would like to try it out.

You must be doing something wrong.
It worked for me, it worked for jacmoe and I had a friend test it, works fine for him as well.

[Bluntspoon]

"Error
You want to download the following file:
http://rapidshare.com/files/98990587/Og ... wsDemo.zip | 6821 KB

Your IP address 196.25.255.250 is already downloading a file. Please wait until the download is completed.

Premium members can download any number of files simultaneously. Become a Premium member now. The download will be available shortly.

Create Premium Account"

It says that even though i'm downloading anything and then you just go round in circles-unless you are a premium user and pay?
Rapidshare has never worked with me.

[Bluntspoon]

Then you try again and...

"Error
You have reached the download limit for free-users. Would you like more?

Get your own premium account now! Instant download access! Or try again in about 15 minutes.

Create Premium Account"

even though i haven't downloaded anything, unless it downloads it secretly and puts it in a secret place?

[Bluntspoon]

Cool, managed to get it via Deutsche Telekom in advanced settings, can't wait to try it out.

[Bluntspoon]

The demo is cool but I need it to work with bumpmapping and directional lights if that's not to much to ask. If anyone has some free time to help a helpless beginner.

[nullsquared]

The demo is cool but I need it to work with bumpmapping and directional lights if that's not to much to ask. If anyone has some free time to help a helpless beginner.

The demo just has the basic idea of VSM - just make your own bump map shader and add the shadowing code. For directional lights, there was discussion a few pages back. Basically, you'd want the post-projection Z instead of world-space length as the depth.

[Ominae392]

Thanks for the lovely tutorial and the sizable number of explanations on the preceding pages. I'm not entirely sure how to describe my issue so I've uploaded the following screenshot to illustrate. This isn't indicative of my entire scene, it only seems to affect shadows being cast on my object so I assume I'm doing something wrong with my mapping. I'm hoping someone will have had a similar problem or might have some idea based on the image.

[nullsquared]

Looks like a bit of acne to me. Does your video card support bilinear filtering of floating point textures?

[Ominae392]

I believe so. I've got an NVidia 8800 gtx.

Upping the pixel format to FP32 gives me the following result:


It's cleaner but I am still stuck with a stair stepping approach. There was a post in another topic about PSVSM that mentioned using a Gaussian filter but you say that your brute force 3x3 filter works. Would something like this help in my case or am I completely misunderstanding the problem?

[nullsquared]

What resolution shadow map are you using, and what is the size of your world units (meters/inches/etc.)?

[Ominae392]

Shadow map res. is 1024. Regarding World Units: I didn't design the model so I have no idea what 1 unit actually equals. But it fits on the demo plane you include in your example so I'll assume it is something meter-like as I don't scale the object's node. The object's max dimensional lengths are (2.5,1.3,1.4). It's supposed to be a trebuchet but I'm not sure how effective a 2 meter high treb. is going to be, hence why I say "meter-like."

[nullsquared]

Shadow map res. is 1024. Regarding World Units: I didn't design the model so I have no idea what 1 unit actually equals. But it fits on the demo plane you include in your example so I'll assume it is something meter-like as I don't scale the object's node. The object's max dimensional lengths are (2.5,1.3,1.4). It's supposed to be a trebuchet but I'm not sure how effective a 2 meter high treb. is going to be, hence why I say "meter-like."

Hm, that should be fine. I'm slightly running out of ideas. Does scaling the node up (2x, 4x, play with it) help out?

[Ominae392]

Shadow map res. is 1024. Regarding World Units: I didn't design the model so I have no idea what 1 unit actually equals. But it fits on the demo plane you include in your example so I'll assume it is something meter-like as I don't scale the object's node. The object's max dimensional lengths are (2.5,1.3,1.4). It's supposed to be a trebuchet but I'm not sure how effective a 2 meter high treb. is going to be, hence why I say "meter-like."

Hm, that should be fine. I'm slightly running out of ideas. Does scaling the node up (2x, 4x, play with it) help out?

Kinda. Scaling down tends to start blurring the step-like shadows together but it's still pretty obvious. Scaling up doesn't seem to do anything. Weird.

[mickeyren]

Hi

I was wondering if this demo also shows soft shadows using point light? I'm looking for examples on soft shadows with point light on the net and I could not seem to find any.

[nullsquared]

Hi

I was wondering if this demo also shows soft shadows using point light? I'm looking for examples on soft shadows with point light on the net and I could not seem to find any.

No, it doesn't. Shadow mapped point lights are a pain in neck, since they require either a texture atlas, a cube map, or 6 textures. All of which are not just slow, but hard to integrat seamless since it's a special case when compared to a spotlight and directional light.

[mickeyren]

Hi

I was wondering if this demo also shows soft shadows using point light? I'm looking for examples on soft shadows with point light on the net and I could not seem to find any.

No, it doesn't. Shadow mapped point lights are a pain in neck, since they require either a texture atlas, a cube map, or 6 textures. All of which are not just slow, but hard to integrat seamless since it's a special case when compared to a spotlight and directional light.

Hi nullsquared,

That's fine, I'm just coming up with a demo id like to have both spot and point light in it - would you know any tutorials or articles that shows how this is done? Apparently, telling me using a cube map or 6 textures won't cut it. Isn't 6 textures == cubemap anyways? I don't know what a texture atlas is either.

I'm fine with any graphics api, or any game engine that actually shows how this is done (except articles from graphic cards vendors).

[nullsquared]

Hi

I was wondering if this demo also shows soft shadows using point light? I'm looking for examples on soft shadows with point light on the net and I could not seem to find any.

No, it doesn't. Shadow mapped point lights are a pain in neck, since they require either a texture atlas, a cube map, or 6 textures. All of which are not just slow, but hard to integrat seamless since it's a special case when compared to a spotlight and directional light.

Hi nullsquared,

That's fine, I'm just coming up with a demo id like to have both spot and point light in it - would you know any tutorials or articles that shows how this is done? Apparently, telling me using a cube map or 6 textures won't cut it. Isn't 6 textures == cubemap anyways? I don't know what a texture atlas is either.

I'm fine with any graphics api, or any game engine that actually shows how this is done (except articles from graphic cards vendors).

I don't know of any demo like that (especially if it can't be from NVidia or ATI for whatever odd reason). A point light has 6 directions (up/down/left/right/forward/backward) compared to a spotlight. Therefore, instead of a 2D depth texture that goes in a single direction, you use a cube map that contains depth in all 6 directions. Then you just use the vector from the light to the object being shadowed as the cube map texture coordinates.

[volca]

Here is an article from GPU Gems about omnidirectional shadow maps: http://http.developer.nvidia.com/GPUGem ... _ch12.html

Maybe It can help.

I think it's sad that the omnidirectional lights are forgotten - they are after all more natural than spotlights or directional lights in some situations (bulbs, candles, etc) - now I don't mean Ogre but the whole game scene with some exceptions (I was surprised to see omnidirectional soft shadows in Call of Juarez)

[_tommo_]

I integrated Ominidirectional Shadows into Ogre once, but it was in fact not much useful... the effect was good, but it was nearly 5 times more slow, and from an artistical perspective, it could be easily "faked" by any other light.
I mean, not often you see a light that radiates in all directions, the only example i can think of is a torch or a fire... and for that you can always glue together 4 spotlights.

[mickeyren]

Therefore, instead of a 2D depth texture that goes in a single direction, you use a cube map that contains depth in all 6 directions. Then you just use the vector from the light to the object being shadowed as the cube map texture coordinates.

I see, I guess its just a convenient way to use a cube map to store all the depth map for all 6 directions, otherwise everything is the same just how you would apply shadow maps with a spotlight.

Does this mean that we also render the full screen shadow map generated from the cubemap 6 times just like when we create shadow maps from a directional or spot lights?

[altren]

First, thank you for very good demo!
I tried to add your shadows into my app and it was quiet easy, but I still have some questions.
Demo is still 99% done and version 0.9, right? Are you going to make 1.0?

Have you tried to use same shadows with directional light?

I also have question why all my objects shadows is transparent at bottom:

Look at shadow near legs. I can't understand why it's transparent.
I have only one light and also tried to use different resolutions for shadow textures (512, 1024, 2048), but always have this effect. Do you know how to avoid it ?
[EDIT] Moving meshes higher from ground make shadows correct, but it doesn't help because all objects should stay on ground.

[nullsquared]

That's caused by the VSM epsilon, the super-small value that is added to the equation of the shadow. It's necessary for numerical stability - however, if you use a 32-bit floating point surface than you can reduce it greatly or even put it at zero to reduce the fading effect.

[NoodlesOnMyBack]

Hi, im trying to get your shaders working with normal maps, i think i almost made it, but something looks weird and i dont know what, im very newbie with shaders, and the code its not optimized, i just wanted to upload the project and if someone can take a look at it and suggest a couple of things i will appreciate it! thanks in advance:
EDIT: I think i solved my problem.

Demo with Shoggoth 1.6.1
http://rapidshare.com/files/207340543/shaders2.rar.html