Hello,

I have created a universe, the sun is at 0/0/0, and 30 planets rotating around it.

Now I added some DOT3-Bumpmapping, but I am not sure about the correct direction.

So is the following code correct, when 0/0/0 is the sun which is the light source, and planet is the current planet? [code] m_vLight.x := planet3d.x; m_vLight.y := planet3d.y; m_vLight.z := planet3d.z; D3DXVec3Normalize(m_vLight, m_vLight); dwFactor := VectortoRGBA(m_vLight, 0.0); SetTexture(0, planet3d.bumptexture); SetRenderState(D3DRS_TEXTUREFACTOR, dwFactor); SetTextureStageState(0, D3DTSS_COLORARG1, D3DTA_TEXTURE); SetTextureStageState(0, D3DTSS_COLORARG2, D3DTA_TFACTOR); SetTextureStageState(0, D3DTSS_COLOROP, D3DTOP_DOTPRODUCT3); [/code] Thanks a lot, Firle

You'll need to transform the light-direction into texturespace (tangentspace) for each vertex, or the direction won't be correct no matter what you do.

Hello tokjunior,

I am a D3D beginner, could you please tell me how to transform it?
The planets are just spheres (with one material), also is the sun.

Firle

You need to take the direction the surface is facing into account.
You need the direction of the lightsource (the sun) relative to the surface.

Or at least that's what I think he means.

You can see better with a picture:
http://img273.echo.cx/img273/9288/jaapexplains9px.png
See?