Hello everybody!

Im working on an implementation of a modelfile from a game. Its actually for learning purpose. Now im facing 3 problems. I dont know if these are simple problems or if its a harder one, but ill post'em here:

1. http://www.imagr.eu/up/4aeea600602bc_agyria.JPG

As you can see it has a problem when i go away from the texture. If i go away very far it gets a picture with only green and blue squares. I think its a problem with the Mipmaps but i dont know what exactly!


2. Alphamaps:

I have 4 layers of textures. every layer has its own 64 x 64 alphatexture. The first layer hast full opacity on every vertex but the next 3 layers have different alphavalues on the vertices. Now im trying to get the blending with the following rendering:



Now actually the textures dont have the alpha-value of the alphamap-texture but either 0 or 255.


3. Selection

I need to get the selectionpoint in my terrain of the mouse. I actually calculate the point on zNear and on zFar but now i got stuck and dont know what to do next to get the selectionpoint. I cant intersect it with a mesh because the terrain isnt rendered as a mesh but vertex-per-vertex.

It would be really cool if someone has a lill hint bout that!

Greetings
Plerion

1.    How do you create and load your textures?
2.    Please use shaders or do you need to run on really old hardware?
3.    In the 3D context selection is called picking. You should find plenty of samples when you use your favorite search engine with this.

Hello!

I load the textures out of memory with the following code:

where format is one of the following constants:
D3DFMT_DXT1
D3DFMT_DXT3
D3DFMT_DXT5

2. Hm, i dont know exactly what you mean with using shaders. I have the following situation:
4 textures with colors and stuff like that, just normal textures with no specific alphavalue
4 textures with alphavalues. just alphavalues for the texture in this terraintile.

It is that you can use one texture for an arbitrary number of terrains. What i tried now was the following:

Now the image is pretty wierd, it has black stripes all over it.

3. Ok, ill have a look, what i can find :D

Greetings

Shader make blending operations just easier to write. For example a modulation operation is just written as color1 * color2, additional blending will be color1 + color2, thats why we are asking please use shaders. So the question is do you have to support pre DX9.0 hardware if not you can just aswell do all this using shaders.

For the picking techniques you really don't want to do a collision detection between all the triangles in the scene, you first want to do a AABB or Bounding Sphere collision detection so you end up with all the objects that are actually on the line you are picking on. This will improve your picking speed massively. It sounds like you want to restructure your terrain a little bit so you don't have to check all your triangles in the terrain even if your only checking the visible ones this will be a massive performance hit.

Ok, that shading sounds interesting, im pretty new to DX, so i think i will have look on that. But i cant really understand why the code above isnt working and presents this image:
http://www.imagr.eu/up/4aef7403d10bd_agerr.JPG

Thats how i understood it:
dev->SetTextureStageState(0, D3DTSS_ALPHAARG1, D3DTA_TEXTURE); // push the alphamap as arg1
dev->SetTextureStageState(0, D3DTSS_ALPHAOP, D3DTOP_SELECTARG1); // select arg1
dev->SetTexture(0, m_alphaMaps[i]); // set the alphamap as stage 0

dev->SetTextureStageState(1, D3DTSS_ALPHAARG1, D3DTA_CURRENT); // alphaarg1 is the alphamap
dev->SetTextureStageState(1, D3DTSS_ALPHAOP, D3DTOP_SELECTARG1); // select alpha from alphamap
dev->SetTextureStageState(1, D3DTSS_COLOROP, D3DTOP_SELECTARG1); // select color from texture
dev->SetTextureStageState(1, D3DTSS_COLORARG1, D3DTA_TEXTURE); // take the texture as arg1
m_3dMgr->SetTexture(m_textures[i], 1); // set the texture as stage 1

m_3dMgr->DrawPrimitives(m_vbuffer, D3DPT_TRIANGLESTRIP, m_striplen, VERTEX_3FT2, m_indices, 145); // draw the composition

But oviously it doesnt produce that!

Try reading the section Creating Blending Stages (Direct3D 9) because you are setting your alpha and color stages in a wrong way.

From the docs.
#define SetTextureColorStage( dev, i, arg1, op, arg2 )     \
dev->SetTextureStageState( i, D3DTSS_COLOROP, op);      \
dev->SetTextureStageState( i, D3DTSS_COLORARG1, arg1 ); \
dev->SetTextureStageState( i, D3DTSS_COLORARG2, arg2 );

#define SetTextureAlphaStage( dev, i, arg1, op, arg2 )     \
dev->SetTextureStageState( i, D3DTSS_ALPHAOP, op);      \
dev->SetTextureStageState( i, D3DTSS_ALPHAARG1, arg1 );  \
dev->SetTextureStageState( i  D3DTSS_ALPHAARG2, arg2 );

Hmm, ok, does that mean, i performed the actions in the wrong order? I changed it to:

dev->SetTextureStageState(0, D3DTSS_ALPHAOP, D3DTOP_SELECTARG1); // alphastage
dev->SetTextureStageState(0, D3DTSS_ALPHAARG1, D3DTA_TEXTURE);
dev->SetTextureStageState(0, D3DTSS_ALPHAARG2, D3DTA_TEXTURE);

dev->SetTexture(0, m_alphaMaps[i]);

dev->SetTextureStageState(1, D3DTSS_ALPHAOP, D3DTOP_SELECTARG1); // alphastage
dev->SetTextureStageState(1, D3DTSS_ALPHAARG1, D3DTA_CURRENT);
dev->SetTextureStageState(1, D3DTSS_ALPHAARG2, D3DTA_TEXTURE);

dev->SetTextureStageState(1, D3DTSS_COLOROP, D3DTOP_SELECTARG1); // colorstage
dev->SetTextureStageState(1, D3DTSS_COLORARG1, D3DTA_TEXTURE);
dev->SetTextureStageState(1, D3DTSS_COLORARG2, D3DTA_CURRENT);

m_3dMgr->SetTexture(m_textures[i], 1);

But it has no visible change.

Call SetTexture() before SetTextureStageState().
Make sure you have texture coordinates for all stages.
If you're using same texture coordinates for all stages, you can call SetTextureStageState(Stage, D3DTSS_TEXCOORDINDEX, StageWithCoord).
For example SetTextureStageState(1, D3DTSS_TEXCOORDINDEX, 0) set texture for stage 1 same as for stage 0.
Set color operations before alpha operations.
Make sure your textures have alphachannel.

Why in one case you're using dev->SetTexture(0, m_alphaMaps[i]) and in other m_3dMgr->SetTexture(m_textures[i], 1)?
Explain meaning of your texture stages. Something like: 0 - Base texture, 1 - Diffuse light map, 2 - Specular light map, 3 - Bump map and so on.

Also, make simple project drawing a single quadrate with textures and experiment with it.

Hello Erida!

Thank you for your tips! I tried everything, but it still is the same picture. The code looks like that now:


The meaning of the textures is as following:
Stage 0: Basetexture for the colors (no alpha should be taken from there)
Stage 1: Alphatexture for the alphavalues (no color should be taken from here and together with the colors from stage 1 this should result in the ARGB)

Now the alphatexture has only an alphachannel and no colors (D3DFMT_A8) and the basetexture is either DXT1, DXT3 or DXT5.

The texcoords and alphacoords are correct as they work in my openGL-application:

The alphating is fixed! I read the alphavalues from the wrong buffer. Im very sorry for the inconveniences...

The problem that rests is the one with the blue and green squares that occure when i go away from the terrain!