Advanced Vertex Shader Demo -- UDK
polycounter lvl 11
Hey guys, I just wanted to share this shader I made.
It's a bit on the expensive side (90 - 115 instructions, depending on static switch params), Anyways I took the idea from Chris Albeluhn (http://www.chrisalbeluhn.com/work.html) and just really added to it.
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http://www.youtube.com/watch?v=e_IvXOPa_gE[/ame]
It's a bit on the expensive side (90 - 115 instructions, depending on static switch params), Anyways I took the idea from Chris Albeluhn (http://www.chrisalbeluhn.com/work.html) and just really added to it.
[ame]
http://www.youtube.com/watch?v=e_IvXOPa_gE[/ame]
Replies
For instance there is a dirty layer in between the wood and the plaster, there is also blending between normal, specular, spec power, and diffuse maps. There is functionality built in that allows individual X and Y scaling of the two respective materials. There is normal map intensity control, and the ability switch between a specular map, or to derive it from your diffuse map. There is also a Static Switch for noisy normal blending. This effect you can see clearly in the video, the normals from the underlying layer show through near the edges of the above layer, giving it that fading thickness look that really adds a lot to the material.
Since this is a true material all of these parameters can be switched out with other maps, or you can scale all of the parameters that you need to adjust the material look.
It can only be used to help break up static mesh building blocks to get some really killer variation. However you have to keep it limited to a small screen space due to the fact that it is so expensive. I'm planning to use it in my new project i'm working on:
Concept by Andreas Rocha
and about the material i'm still not digging it, sorry. just personal opinion, i'm sure people who think more technically would really appreciate it. I would rather just use a few different textures, as photoshop is a great way of adding those details!
Hitez: You should read the thread I linked too, get an understanding of how useful this is.
Anyway, cool post, but again would be far more interesting if the actual material setup were posted.
One gripe - it's not vertex shader. It's a pixel shader that uses custom vertex colors :P
Ah, thanks for clearing that up, thought the resolution on that plane seemed a bit high for vertex painting.
Blastradius: Most all major 3d suites allow you to paint vertex colors into the model, you can even export them in your ASE file and use the color information in the material editor.
Crazy Fingers - The resolution on those planes was 4x4. it had 16 verts. The shader is cool because it uses the vertex paint and adds in a noise map to the vertex transition. That way you can paint on low detail meshes and still get a really interesting noisy transition.
MoP - i actually didn't see that thread. i'm going to read it now tho.
The shader has alot of instructions, but it's okay to use on things that don't take up too much of screenspace. As you saw in the concept the parts i would be using it on will only take up around 20% of the screen so it won't impact performance that well.
When you see "90 instructions" it means that it has to do 90 instructions to render each pixel on your screen. so if you have a 150 instruction material on an object that only takes up like 3% of the pixels on screen, it won't impact performance that much.
Here's a grab of the network. I don't feel like piecing high res screenshots of it together at this hour of the night, so this will have to do for now.
PS - If a mod sees this thread can you rename it to "Advanced Material Demo - Vertex Painting"
nice shader work
about your texture coordinates, why do you split up the tex coordinates in R and G? you could easily just multiply the texcoords with the appendvector of 2 inputs, dunno if it saves instructions but its only 5 nodes as compared to your 7 and does exactly the same
Here is a video of the shader in action.
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So here's what i did.
First i subtracted the red channel of the vertex color node by the height map, then divided it by the alpha channel of the vertex color node. Then i clamped that input to a value between .01 and 1. That's it. That little set of instructions is all you'll need for your linear interpretation. That little bit of math came from MoP. So credit goes there
After that i used the blue channel of the vertex color and multiplied it by 10 on the Blue channela constant 3 vector, Then i plugged that node into the World Position Offset input at the bottom of the material's master node
The shader in this demo is only 65 Instructions
here's a demo
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Reminds me of DiabloII
edit : is a vertexcolor based particle emitter possible?
http://www.chrisalbeluhn.com/UDK_World_Position_Offset.html
Near the bottom of the page, this is explained a little further.
The shader network is created similar to the one i have on my page if you want a walk through on how some of it is done, or at least the theory behind it.
As for the deformation of the terrain, if you are wondering, an easy way to get this to work is to take a constant 3 vector with a value of 0,0,5 (the 5 can be whatever value you want it to be) and 'multiply' that by the alpha of a 'vertex color' node. This will then be plugged into the 'WorldPositionOffset'. When you paint out your alpha value, you will now see a deformation. Remember that you can deform something in the positive direction based on the original geometry normals, but not the negative. if you want to go negative, you'll have to make your material additive or transparent.
yeah its pretty fucking slick, always wandered if uncharted 2 used something similar for their snow pass, only i thought they were using normal info like perhaps blue channel as a mask..
This one had AUDIO.
Enjoy.
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Is there a reason to use BSP in UDK anyway? Or can I just starting using only meshes?
Right click on your BSP and convert it to a static mesh. Then just right click again on the BSP and select replace, then your newly created static mesh will take the place of that BSP.
Be cool to get some detailed screens on the shader setup so we can mess around with it :P
Damn, that's awesome!
EDIT: Actually, that doesn't work out too well, didn't seem to work when I had subtracted some holes in my BSP, even if I selected those too.
Best way is just to make the meshes from the beginning I think, but I'm more interested in what's the upside/downside to using meshes vs BSP when it comes to your basic building blocks.
Clockwork think of BSPs as the most basic, inexpensive way of shelling out your level. You don't NEED to use BSP brushes, it just helps for getting basic forms and shapes down that you don't want to make custom meshes for. You also have to remember that this material only works if there is an even amount of vertices being distributed throughout the mesh surface that you want to paint on. In the case of the demo shader, it was being used on a 512x256 wall with i think..... 28 vertices overall.
The techniques being used in this shader are pretty cool. I'm using a bunch of mixmaps and other maps in conjunction with some clever mathematical instructions to re-use and invert masks to effect other cool things.
The best example of this --- The cracks normal map has an ambient occlusion map embedded in the normal's alpha. So when i paint the normal information in with the green channel, it is also painting in AO onto the diffuse.
I'll see if i can post the shader up later tonight for you guys to play with. Right now it's getting pretty complex, although it's only 84 instructions.
I'm thinking mostly about performance/technical stuff, not artistic.
Let me give you an example, I have a room, a hallway actually, or corridor, on each side of it is 10 rooms, so there's a total of 20 rooms in addition to the corridor. These are cells, prison cells.
I built all this out of BSP, so each cell consists of these BSPs: Ceiling, Floor, 4x Walls, in one wall I substracted a hole for the doorway into the corridor. I've found out that subtraction with BSP works out really well in UDK, the documents say so as well, it's not like in past engines or in 3D apps where booleans cause a whole lot of mess.
For door frames, and doors, things like that, I made meshes of course. But now I'm thinking, is it more cost effective, performance wise, to build the just one big volume for the whole room in BSP, then each cell should be a mesh?
It's called binary space partition for a reason
EDIT: By the way what i am doing right now is figuring out the mathematics behind re-using alpha masks for the texture blends to create more interesting results. For instance, i have the cracks being painted on on a different channel. But it would be cool if we could free that channel up by using the red channel's Alpha mask to procedurally create the cracks. Think of it as extending the falloff... the expression i have in theory will work but i havn't gotten around to testing it yet.
I hope to have something for u guys soon