Terrain Alpha Blending

(G0-Gerbil) #81

Just to note, using this method over normal terrain appears to have a reasonably substantial speed hit in your maps, so use it sparingly.
One idea is to only use this shader on areas you aren’t sure which terrain they’d take (IE the joining areas) and use duplicate, but single pass (IE non alpha’ed or dotprod’ed) shaders for the flat areas you know are ‘safe’.

(G0-Gerbil) #82

As a comment to above, it would hurt most cards that only allow 2 render passes per thingy - not sure how prevelant these are these days anyway.
Reading sock’s comments about layers though makes me ask a couple of things:

  1. Does anyone bother using detail textures?
  2. Are all passes the same? EG is an image blended via vertex generated alpha (3 point, interpolated) the same as an image blended with a detailled alpha channel modified by dotprod etc? Me knows squat about gfx cards internally, so am curious.
(=ds=bart) #83

sorry for asking bud i geth htis i guess it has something to do with update for q3 is there a link to the right file for q3

WARNING: Unknown q3map_alphaMod method: set
WARNING: Unknown q3map_alphaMod method:
dotproduct2

(nUllSkillZ) #84

I think you need the latest version of q3ma2.
There is a download link in the stickies of the q3map2 forum.

(]UBC[ McNite) #85

Any update or experiences on how the use of large areas of alphablended terrain impacts FPS? If I read GO-Gerbil right, he s contradicting sock who states it doesn’t matter whether you use old terrain blending with a .pcx as alpha-image or new alphablending with large areas covered in the new way.
Currently the worst areas in Warbell run with about 120 FPS on localhost, and I didn’t want to spend all the effort of re-texturing to find out that the FPS go suck then…

Also I noticed 2 things in TheRiver II Redux. While I was having the whole terrain as about 20 func_groups and not as 1 terrain func_group, the BSP was about 1 meg bigger compared to when I merged all those func_groups into one and gave them the old terrain blending with the alpha-image. Anybody having experiences about similair things with new alpha-blending?

(kat) #86

Did you ‘detail’ flag the func_groups? In theory you shouldn’t be experiencing any slow downs unless you’ve got a massive draw distance and that’s going to be effected by everything being drawn, not just the alpha blended terrain.

(Flippy) #87

hey… i just downloaded the sample maps from the terarin blending article… i rebuild one of the test maps myself and it worked :slight_smile:

but i have a question, the textures supplied with the sample maps, can i use them in my maps? or do i have to find my own textures for it…?

edit,

also, is it possible to have say a grassy plain in your map, which is blended with a differnet kind of grass at random places? to prevent tiling and having the same texture everywhere…

(Flippy) #88

Ok i tried it with temperate_sd textures now (i still used the shader from the article, but i made my own “grass (moss) to rock” shader…

im not too happy with it however…

here’s a pic:

things im bothered with:

  • the blend is very sharp (its hardly a blend :\ )
  • the rock texture (which is on the “upright” part of the rock and is not a blended texture) does not align with the blended rock parts (dunno if this is supposed to be… how can i make it align properly?)
(Diego) #89

Do the SD texture have alpha channels? You won’t get a proper blend without one. Only the secondary texture needs it though. So, if rock is your primary, it does not need an alpha. But in any blends between rock/grass, rock/mud, rock/dirt, the grass/mud/dirt textures need an alpha channel.

If you want to blend between secondary textures, you will need to make a new set of blend shaders. That way you can blend textures like this: rock/grass/dirt/grass/rock

If you downloaded the .psd files from Sock’s website, you can see how he made his textures. You CAN use his. Just give him credit. I suggest you at least use his to get everything working – using different texture names. Then you can always edit the images later.

Not sure about how he blended the rock walls to the ground. I know he used shaders that were not really related to the ground shaders. I’m not using alpha mod to blend walls to ground or to blend vegetation into my walls. But it is easy to see that the textures on top of your wall are projected differently from the textures on the side of the wall.

(Flippy) #90

No the temperate_sd textures dont have alpha channels, however, i made them myself the way its described a few times in this thread… and the blend is working, it’s just not working how i want it to work…

(Diego) #91

Can you post a pic of your alpha channel?

(Flippy) #92

Here’s the textures i used:

ter_moss1:

And it’s alpha channel:

ter_rock3:

And it’s alpha channel:

(Diego) #93

Your textures look fine. I think the problem is more in the way in which you are trying to use them.

Sock’s samples did not blend between the grass on the ground and the rock walls. That is a technique you frequently see done with easygen terrain and blending between two terrain shaders. In his samples, the terrain textures end at the base of the cliff walls. He then uses 2 shaders on the rock walls create vertical blends to the base of the wall.

In more complex examples, the grass terrain would blend to a different rock texture that is similar in color and tone to the rock wall texture. But he keeps these brushes flat so the projection does not start to get stretched like yours are doing.

I found that it was much more helpful to download Sock’s “Pyramid of the Magician” map for quake 3 to see a more detailed example of how he blended his textures. I didn’t have quake 3 at the time so I made a working conversion of it for ET to study.

For myself, I decided not to use the vertical blending on the rock walls. Instead, I have 4 very large rock textures. 2 of them, based off of Sock’s textures, are used for vertical walls and I have the blend between the two textures painted into them. I just apply these textures like I would the wall of a building. The 3rd is smoother stone that I use for my rock/grass blend. I use this shader on top of the cliffs. The 4th is a rough rocky stone that I use for cave interiors. I then have primary and secondary blends between rock, grass, mud, and cobblestones.

(d3coy) #94

Diego, im looking for some good textures for the blending, Ive tried my own but just lack the knowledge to write the shaders I think. My blends are working very well, but its just not the theme im looking for. Would you be willing to share the onces you are refering to in your last post?

(Diego) #95

My shaders are just copies of Sock’s. No shader knowledge required to do that :slight_smile: If your blends are working well, I can’t imagine that your shaders need any work.

So, for theme, I guess that you don’t like the style of textures that you are using. I’m not to thrilled with the ET textures either. I’ve seen them so much that I wanted to have a fresh look to my map. My terrain textures are modified versions of Sock’s textures that I blended with textures from other games like Call of Duty and Jedi Knight. And that is something that not everyone here would approve of.

In Sock’s examples, he describes how he created his alpha channels from the source images that had no alpha. I just followed his example. For my mud, I just used his alpha channel because it worked better than the one I made.

Also, although the blending changes depending upon the angles of the terrain brushes, I’ve found that I just don’t get very noticable blending without using the alpha mod brushes. So, I use 100% and 0% brushes all over the place. Only rarely do I use a softer blend like 25% 50% or 75%.

As far as sharing them is concerned, if you need shaders, these I will be happy to share. But I don’t want to share the textures until I release the map. I’m a very slow mapper. I’ve been working on this map for about 2 years now learning as I go. I like to think that I have a unique look to my map and I would prefer if someone else didn’t release a map with my textures before me.