Retro Modding Wiki

Materials (Metroid Prime): Difference between revisions

Page Discussion

Materials (Metroid Prime) (view source)

Revision as of 19:41, 4 March 2018

3,360 bytes removed ,  4 March 2018
→‎Flags
VisualWikitext
>Aruki
m (→‎Color Channels: ok, seems original theory was correct :P)
>Aruki
 
(28 intermediate revisions by 2 users not shown)
Line 1: Line 1:
The format for '''materials''' is seen in both the [[CMDL (Metroid Prime)|CMDL]] and [[MREA (File Format)|MREA]] formats and is identical in both. This particular material format appears in both Metroid Prime and Metroid Prime 2 with minor differences.
The format for '''materials''' is seen in both the [[CMDL (Metroid Prime)|CMDL]] and [[MREA (File Format)|MREA]] formats and is identical in both. This particular material format appears in both Metroid Prime and Metroid Prime 2 with minor differences.


{{research|minor|There are two unknown values left in the MP1 material format, and there might be some unknown flag settings. Also, everything that was introduced in Echoes (two general settings and a vertex attribute) is unknown.}}
{{research|minor|MP1's materials are completely understood, but MP2 introduced two new values that are both unknown.}}


__TOC__
__TOC__
Line 76: Line 76:
| long
| long
| 1
| 1
| {{unknown|'''Unknown'''}}
| '''Group index'''
|-
|-
| long
| long
Line 96: Line 96:
| long
| long
| 1
| 1
| {{unknown|'''Unknown''' ''(note: only present if flag 0x400 is set!)''}}
| '''Reflection indirect texture slot index''' ''(note: only present if flag 0x400 is set!)''
|-
|-
| long
| long
Line 113: Line 113:
==== Flags ====
==== Flags ====


These are the known flag settings:
These are simple boolean settings that can be toggled on and off on each material. These are the known flag settings:


{| class="wikitable"
{| class="wikitable"
Line 122: Line 122:
| 0
| 0
| 0x1
| 0x1
| Appears unused, but always set
| Unused, always set ''(never set in Echoes)''
|-
|-
| 1
| 1
| 0x2
| 0x2
| Appears unused, but always set
| Unused, always set
|-
|-
| 2
| 2
| 0x4
| 0x4
| Appears unused, but always unset
| Unused, never set
|-
|-
| 3
| 3
| 0x8
| 0x8
| Enable Konstant values
| Has Konst values
|-
|-
| 4
| 4
| 0x10
| 0x10
| Mark transparent material
| Transparent
|-
|-
| 5
| 5
| 0x20
| 0x20
| Enable punchthrough alpha
| Masked alpha (compare threshold is hardcoded at 0.25)
|-
|-
| 6
| 6
Line 150: Line 150:
| 7
| 7
| 0x80
| 0x80
| Enable depth writing
| Enable Z-writes
|-
|-
| 8
| 8
| 0x100
| 0x100
| {{unknown|Unknown}}
| Enable Samus's reflection, using the eye position and projection direction from the surface header
|-
|-
| 9
| 9
| 0x200
| 0x200
| Don't draw
| Shadow occluder mesh; meshes using this material are not rendered, but can be used to cast dynamic shadows on actors
|-
|-
| 10
| 10
| 0x400
| 0x400
| Enable second unknown value
| Enable indirect texture stage for reflections
|-
|-
| 11
| 11
| 0x800
| 0x800
| {{unknown|Unknown}}
| Indicates a lightmap is present; no ingame effect
|-
|-
| 12
| 12
| 0x1000
| 0x1000
| {{unknown|Unknown}}
| Unused, always set ''(never set in Echoes)''
|-
|-
| 13
| 13
| 0x2000
| 0x2000
| Enable lightmaps; first UV coordinate uses short array instead of float array
| Enable first UV coordinate to use short array instead of float array (used for world lightmaps)
|-
|-
| 14
| 14
| 0x4000
| 0x4000
| {{unknown|Unknown}}
| {{unknown|In MP1, unused, never set; in Echoes, unknown}}
|-
|-
| 15
| 15
| 0x8000
| 0x8000
| {{unknown|Unknown}}
| {{unknown|In MP1, unused, never set; in Echoes, unknown}}
|-
|-
| 16
| 16-31
| 0x10000
| 0xFFFF0000
| {{unknown|Unknown}}
| TEV texture flags; a bit set indicates that the corresponding TEV stage uses a texture. No ingame effect.
|-
| 17
| 0x20000
| {{unknown|Unknown}}
|-
| 18
| 0x40000
| {{unknown|Unknown}}
|-
| 19
| 0x80000
| {{unknown|Unknown}}
|-
| 20+
| 0x100000+
| Unused; never set
|}
|}


==== Vertex Attribute Flags ====
==== Vertex Attribute Flags ====


These flags are generally toggled in pairs, with each pair corresponding to a vertex attribute; if a pair is set, then vertices using this material will have the corresponding attribute. This is vital for reading geometry.
These flags are generally toggled in pairs, with each pair corresponding to a vertex attribute; if a pair is set, then vertices using this material will have the corresponding attribute. This is vital for reading geometry. Starting in Echoes, each pair is used to indicate the size of the attribute indices in the geometry data, with 3 meaning a 16-bit index and 2 meaning an 8-bit index. (This isn't actually used, though; the original game data always uses 16-bit indices.)


An important note is that while the leftmost byte is not used in Prime 1, in Echoes there's occasionally a value there that toggles an extra vertex attribute preceding position. This needs research to determine what the new attribute actually is. Also, GX supports up to 8 texture coords per vertex, but the game doesn't seem to allow you to assign more than 7 (though this could do with some double-checking).
GX supports up to 8 texture coords per vertex, but the game doesn't seem to allow you to assign more than 7 (though this could do with some double-checking).


These are the possible attributes:
These are the possible attributes:
Line 250: Line 234:
| Tex 6
| Tex 6
|}
|}
Echoes introduces some new attributes using the top byte of the flags value; unlike the other flags, these are not set in pairs. Each individual bit indicates the presence of a different attribute. The indices in the geometry data are always 8 bits.
{| class="wikitable"
! Bit
! Attribute
|-
| 0x1
| Position Matrix Index
|-
| 0x2
| Tex0 Matrix Index
|-
| 0x4
| Tex1 Matrix Index
|-
| 0x8
| Tex2 Matrix Index
|-
| 0x10
| Tex3 Matrix Index
|-
| 0x20
| Tex4 Matrix Index
|-
| 0x40
| Tex5 Matrix Index
|-
| 0x80
| Tex6 Matrix Index
|}
==== Group Index ====
The group index marks groups of materials that all have the same settings, but different textures. The game will check the value after loading the textures (but prior to the vertex attribute flags), and check whether the group index set on the material matches the material currently set up. If it does, it will skip the rest of the material setup. The value typically starts at 0 on the first material and increments by 1 on each new group with different settings.


==== Konst Colors ====
==== Konst Colors ====
Line 324: Line 343:
There's only one set of flags, which operates on COLOR0. COLOR1 is reserved for dynamic shadows (terrain casting shadows on actors), so its settings can't be directly modified. Here's how the other color channel settings work.
There's only one set of flags, which operates on COLOR0. COLOR1 is reserved for dynamic shadows (terrain casting shadows on actors), so its settings can't be directly modified. Here's how the other color channel settings work.


COLOR1A1's settings vary depend whether shadowmaps are enabled:
COLOR1A1's settings vary depending on whether shadowmaps are enabled:


* No processing will be done if the count value is 0. Otherwise, the count value is ignored; the game will always set up both color channels.
* No processing will be done if the count value is 0. Otherwise, the count value is ignored; the game will always set up both color channels.
Line 624: Line 643:


=== UV Animations ===
=== UV Animations ===
'' See [[UV Animations]]''


The UV animations section immediately follows the texgen flags. Its purpose is to generate texture matrices and post-transform matrices, which are then used to transform UV coordinates. This is commonly used to animate textures via simple UV scrolls, but it's also often used to simulate reflective surfaces that move with the camera. Materials can have multiple UV animations; in that case, each animation generates a separate texture/post-transform matrix and are loaded into GX sequentially. Texgen is used to set which matrices are used by which UV coordinates (if any).
The UV animations section immediately follows the texgen flags. Its purpose is to generate texture matrices and post-transform matrices, which are then used to transform UV coordinates. This is commonly used to animate textures via simple UV scrolls, but it's also often used to simulate reflective surfaces that move with the camera. Materials can have multiple UV animations; in that case, each animation generates a separate texture/post-transform matrix and are loaded into GX sequentially. Texgen is used to set which matrices are used by which UV coordinates (if any).
Line 643: Line 664:
|}
|}


The structure of the animations themselves is somewhat simple. Each animation has a 32-bit ''mode'' setting, followed by a number of float parameters. The number and usage of these float parameters varies depending on what mode is set. There are 8 possible modes.
For info on how to read the animation data and how each animation mode works, see [[UV Animations]].
 
For all of the following modes, ''s'' refers to ''seconds mod 900''.
 
==== Mode 0: Inverse ModelView Matrix (No Translation) ====
 
This mode is commonly used with vertex normals to simulate reflective surfaces using spheremaps that move with the camera. It takes no parameters, and will generate both a texture matrix and a post-transform matrix. Translation is ignored.
 
The texture matrix is calculated like this. Note that the multiplication of the view matrix by the model matrix should be modified slightly rather than being a straight multiplication to ignore translation on the model matrix. (The game uses a function called MultiplyIgnoreTranslation for this.)
 
<pre>texmtx = inverse(ViewMatrix) * ModelMatrix;
texmtx[0][3] = texmtx[1][3] = texmtx[2][3] = 0;</pre>
 
The post-transform matrix is a constant value. [1][1] and [1][2] may need to be swapped around for correct playback.
 
<pre>0.5, 0.0, 0.0, 0.5,
0.0, 0.0, 0.5, 0.5,
0.0, 0.0, 0.0, 1.0</pre>
 
==== Mode 1: Inverse ModelView Matrix ====
 
This mode is nearly identical to mode 0; the only difference is that translation is left as-is. The multiplication of the view matrix by the model matrix actually is a straight multiplication in this mode, and the translation values on the texture matrix aren't set to 0.
 
==== Mode 2: UV Scroll ====
 
This mode is used to scroll both U and V at the same time. It will only generate a texture matrix. It has four float parameters: ''offsetA'', ''offsetB'', ''scaleA'', and ''scaleB''.
 
<pre>uOffset = (s * scaleA) + offsetA;
vOffset = (s * scaleB) + offsetB;</pre>
 
==== Mode 3: Rotation ====
 
This mode rotates the texture. It will only generate a texture matrix. It has two float parameters: ''offset'' and ''scale''.
 
<pre>float angle = (s * scale) + offset;
float acos = cos(angle);
float asin = sin(angle);
float translateX = (1.0 - (acos - asin)) * 0.5;
float translateY = (1.0 - (asin + acos)) * 0.5;</pre>
 
The resulting texture matrix is laid out as:
 
<pre>acos, -asin, 0.0, translateX,
asin,  acos, 0.0, translateY,
0.0,  0.0, 1.0,        0.0</pre>
 
==== Mode 4/5: Horizontal/Vertical Filmstrip ====
 
These modes can be used to create a filmstrip-like effect. The texture steps a set distance each animation frame, rather than the scroll being smoothly interpolated every game frame. The same calculation is done for both modes, with the only difference being whether the calculated offset is applied to the U or V coordinate. It will only generate a texture matrix. There are four float parameters: ''scale'', ''numFrames'', ''step'', and ''offset''.
 
The animation is made up of a number of pseudo-frames, where ''step'' controls the amount that the texture scrolls by each frame, and ''numFrames'' sets how many frames are iterated through before resetting back to 0. ''scale'' roughly controls animation playback speed, and ''offset'' modifies the time input value.
 
<pre>float value = step * scale * (offset + s);
float uv_offset = (float)(short)(float)(numFrames * fmod(value, 1.0f)) * step;</pre>
 
==== Mode 6: Model Matrix ====
 
This mode is similar to modes 0 and 1 in that it simulates reflective surfaces, but it only takes the model matrix into account, which means camera movement doesn't affect the reflection. It takes no parameters and it generates both a texture matrix and a post-transform matrix.
 
The texture matrix is simply the model matrix, with the translation values set to 0. The post-transform matrix is set to the following:
 
<pre>0.5, 0.0, 0.0, ModelMatrix[0][3] * 0.50000001,
0.0, 0.0, 0.5, ModelMatrix[1][3] * 0.50000001,
0.0, 0.0, 0.0, 1.0</pre>
 
==== Mode 7: Mode-Who-Must-Not-Be-Named ====
 
Mode 7 takes two parameters and generates both a texture matrix and a post-transform matrix. We don't know what to name it.
 
The texture matrix is generated the same way as in mode 0; translation is ignored.
 
<pre>texmtx = inverse(ViewMatrix) * ModelMatrix;
texmtx[0][3] = texmtx[1][3] = texmtx[2][3] = 0;</pre>
 
The post-transform matrix is where it gets a little complicated. A little math is required to calculate some values:
 
<pre>float xy = ((ViewMatrix[0][3] + ViewMatrix[1][3]) * 0.025f * ParamB;
xy = (xy - (int) xy); // This truncates the integer portion of the value, leaving only the fractional part (mantissa).
 
float z = ViewMatrix[2][3] * 0.05f * ParamB;
z = (z - (int) z);
 
float halfA = ParamA * 0.5f;</pre>
 
The post-transform matrix is then constructed as:
 
<pre>halfA, 0.0f,  0.0f,  xy,
0.0f, 0.0f, halfA,  z,
0.0f, 0.0f,  0.0f, 1.0f</pre>


[[Category:File Formats]]
[[Category:File Formats]]
[[Category:Metroid Prime]]
[[Category:Metroid Prime]]
[[Category:Metroid Prime 2: Echoes]]
[[Category:Metroid Prime 2: Echoes]]
Anonymous user
Retrieved from "https://wiki.axiodl.com/w/Special:MobileDiff/2136...2165"