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Posted: Sun Nov 30, 2008 12:10 am
by Baker
goldenboy wrote:I think I remember transparent water in software in FTE - dunno if it also does alpha entities. I should test. :-E
I've heard that FTE uses 24 bit color in software mode. If true, the issue of the constrained limitation of 256 colors for the whole window doesn't come into play.
Posted: Mon Dec 01, 2008 1:32 pm
by Tomaz
This is like the 5:th tutorial from you that i read that shows a feature and list a few engines that supports it, and also the 5:th tutorial that doesnt list TomazQuake as one of the engines supporting it.
Nice tutorial, but why do I get the feeling you're not really sure what you're doing?
1) You send a 2 then the transluceny value, then you read it into a temp which isnt used, why not just not send it?
2) Why are you using floats when a byte is more than enough?
0-255, just do / 255.0f;
3) So now you have support for transparent object, but where is the alpha sorter? Sure the objects will be transparent, but 99.9% of the time there will be objects in behind the transparent object that wont be rendered.
Here is why:
Lets use a window in a map as the transparent object.
Whenever the window is rendered it also writes to the z-buffer. If this is rendered BEFORE an object behind the window, lets say a monster, that monster wont be visible through the window because the 3d card will reject it isnce its to far away in the z-buffer.
The sollution, always render opaque objects first ( thatd be the ones not being transparent ) and then render all transparent object SORTED from back to front. This will work fine for things like a window, but for object with a more complex geometry it might not be enough to sort the object from back to front, one might have sort every triangle from back to front ( which i think DP does, or at least did at some point ).
TomazQuake didnt go that far, one thing I DID do tho was fixing so the particle system works with water ( which isnt covered here either ) which does a similar thing. There i sort all the particles as being either in front or behind the water plane. So the render order is, Particles behind water, water, particles in front of water.
Enough from me in this thread, im gonna comment a few more of your tutorials tho.
Posted: Mon Dec 01, 2008 9:59 pm
by r00k
Code: Select all
void SortEntitiesByTransparency (void)
{
int i, j;
entity_t *tmp;
for (i = 0 ; i < cl_numvisedicts ; i++)
{
if (cl_visedicts[i]->transparency < 1 && cl_visedicts[i]->transparency > 0)
{
for (j = cl_numvisedicts - 1 ; j > i ; j--)
{
// if not transparent, exchange with transparent
if (cl_visedicts[j]->transparency == 1)
{
tmp = cl_visedicts[i];
cl_visedicts[i] = cl_visedicts[j];
cl_visedicts[j] = tmp;
break;
}
else
continue;
}
if (j == i)
return;
}
}
}
Posted: Mon Dec 01, 2008 10:36 pm
by Baker
Tomaz wrote:Whenever the window is rendered it also writes to the z-buffer. If this is rendered BEFORE an object behind the window, lets say a monster, that monster wont be visible through the window because the 3d card will reject it isnce its to far away in the z-buffer.
Ah! I noticed that but didn't know why that was happening. I wasn't seeing monsters behind windows, etc.
@Rook: where should have that called from?
Edit = nevermind, got it
Code: Select all
void R_DrawEntitiesOnList (void)
{
int i;
if (!r_drawentities.value)
return;
SortEntitiesByTransparency ();
Edit #2 = Cool! Much better.
Posted: Sat Aug 22, 2009 11:23 pm
by mh
r00k wrote:Code: Select all
void SortEntitiesByTransparency (void)
{
int i, j;
entity_t *tmp;
for (i = 0 ; i < cl_numvisedicts ; i++)
{
if (cl_visedicts[i]->transparency < 1 && cl_visedicts[i]->transparency > 0)
{
for (j = cl_numvisedicts - 1 ; j > i ; j--)
{
// if not transparent, exchange with transparent
if (cl_visedicts[j]->transparency == 1)
{
tmp = cl_visedicts[i];
cl_visedicts[i] = cl_visedicts[j];
cl_visedicts[j] = tmp;
break;
}
else
continue;
}
if (j == i)
return;
}
}
}
No, that's gonna group the entities, but it won't sort them back to front. Not to mention being the
WRONG sorting algorithm.
You need to check entities at the point at which they're added to the cl_visedicts array, if they have transparency then add them to a second cl_transedicts array, then do something like this:
Code: Select all
int D3D_EntityDepthCompare (const void *a, const void *b)
{
entity_t *enta = *((entity_t **) a);
entity_t *entb = *((entity_t **) b);
// sort back to front
if (enta->dist > entb->dist)
return 1;
else if (enta->dist < entb->dist)
return -1;
else return 0;
}
void D3D_DrawTranslucentEntities (void)
{
if (!r_drawentities.value) return;
if (!d3d_RenderDef.numtransedicts) return;
// if there's only one then the list is already sorted!
if (d3d_RenderDef.numtransedicts > 1)
{
// evaluate distances
for (int i = 0; i < d3d_RenderDef.numtransedicts; i++)
{
entity_t *ent = d3d_RenderDef.transedicts[i];
// set distance from viewer - no need to sqrt them as the order will be the same
// (fixme - should we, and then subtract a radius?)
ent->dist = (ent->origin[0] - r_origin[0]) * (ent->origin[0] - r_origin[0]) +
(ent->origin[1] - r_origin[1]) * (ent->origin[1] - r_origin[1]) +
(ent->origin[2] - r_origin[2]) * (ent->origin[2] - r_origin[2]);
}
if (d3d_RenderDef.numtransedicts == 2)
{
// trivial case - 2 entities
if (d3d_RenderDef.transedicts[0]->dist < d3d_RenderDef.transedicts[1]->dist)
{
// reorder correctly
entity_t *tmp = d3d_RenderDef.transedicts[1];
d3d_RenderDef.transedicts[1] = d3d_RenderDef.transedicts[0];
d3d_RenderDef.transedicts[0] = tmp;
}
}
else
{
// general case - depth sort the transedicts from back to front
qsort ((void *) d3d_RenderDef.transedicts, d3d_RenderDef.numtransedicts, sizeof (entity_t *), D3D_EntityDepthCompare);
}
}
// global state for translucent ents - we're drawing back to front so we can write to Z
D3D_EnableAlphaBlend (D3DBLENDOP_ADD, D3DBLEND_SRCALPHA, D3DBLEND_INVSRCALPHA, false);
// now draw 'em
// we can't state-batch these as they need correct ordering so we'll just live with the state changes...
for (int i = 0; i < d3d_RenderDef.numtransedicts; i++)
{
d3d_RenderDef.currententity = d3d_RenderDef.transedicts[i];
if (d3d_RenderDef.currententity->model->type == mod_sprite)
D3D_DrawSpriteModel (d3d_RenderDef.currententity);
else if (d3d_RenderDef.currententity->model->type == mod_alias)
D3D_DrawTranslucentAliasModel (d3d_RenderDef.currententity);
else if (d3d_RenderDef.currententity->model->type == mod_brush)
R_DrawBrushModel (d3d_RenderDef.currententity);
else
{
// just print a warning
Con_DPrintf
(
"Unknown model type %i for %s\n",
d3d_RenderDef.currententity->model->type,
d3d_RenderDef.currententity->model->name
);
}
}
// take down global state
D3D_DisableAlphaBlend ();
}
You could also accomplish similar with a Mod_PointInLeaf, storing translucent ents in leafs, then doing a BSP tree walk, but this way is much simpler overall, especially as there will (hopefully!) only be a small handful of translucent ents in any given scene. qsort speeds are comparable to a BSP walk even for all surfs in the view anyway, so best not to even go there.
Even then it won't handle cases where alpha ents are overlapping, but that's probably getting into too much complexity (especially if they have different model types).
Posted: Sat Aug 22, 2009 11:35 pm
by revelator
hmm strange that one seems kinda familiar
ah aye
Code: Select all
// sort draworder by depth
int R_DepthSortSprites(const void *arg1, const void *arg2)
{
draworder_t *pOrder1, *pOrder2;
static int diff;
pOrder1 = (draworder_t *) arg1;
pOrder2 = (draworder_t *) arg2;
if (pOrder1->depth > pOrder2->depth)
{
diff = -1;
}
else if (pOrder1->depth < pOrder2->depth)
{
diff = 1;
}
else
{
diff = 0;
}
return diff;
}
Code: Select all
typedef struct draworder_s
{
float depth;
int order;
} draworder_t;
Code: Select all
void R_DrawSpritesOnList (void)
{
int i;
entity_t *tempentity;
draworder_t sprite_order[MAX_EDICTS];
vec3_t temp_org = {0, 0, 0};
vec3_t sprite_org;
if (!r_drawentities.value) return;
// make new list of ents by depth and current order in list
for (i=0 ; i<cl_numvisedicts ; i++)
{
tempentity = cl_visedicts[i];
VectorCopy(tempentity->origin, sprite_org);
VectorSubtract(sprite_org, r_origin, temp_org);
sprite_order[i].depth = Length(temp_org);
sprite_order[i].order = i;
}
// sort this new list by depth, back to front
qsort(sprite_order, cl_numvisedicts, sizeof(draworder_t), R_DepthSortSprites);
// classic quake only has a handful of sprites: light globes, bubbles and explosions.
// hipnotic added a few more, but they looked ghastly even back in the late 90s, so
// we'll just pretend they never happened. the main ones we want to deal with are
// the globes and bubbles. sprite replacement is handled in the drawing routine.
for (i=0 ; i<cl_numvisedicts ; i++)
{
currententity = cl_visedicts[ sprite_order[i].order ];
// not an sprite model
if (currententity->model->type != mod_sprite) continue;
// occluded during previous pass
if (currententity->occluded) continue;
R_DrawSpriteModel (currententity);
}
}
could probably be used for the same ?
Posted: Sun Aug 23, 2009 10:53 am
by mh
Kinda, but it's not really calculating the distance correctly. Check my dist calc above, and remember that you don't need to sqrt the result cos if x > y then sqrt(x) also > sqrt (y).
Posted: Sun Aug 23, 2009 11:27 am
by revelator
noticed
hmm lemme see what i can cook up.
Posted: Sun Aug 23, 2009 9:10 pm
by Lardarse
mh wrote:Kinda, but it's not really calculating the distance correctly. Check my dist calc above, and remember that you don't need to sqrt the result cos if x > y then sqrt(x) also > sqrt (y).
I think that there are exceptions when both are less than 1, but I might be wrong...
Posted: Sun Aug 23, 2009 9:13 pm
by Team Xlink
So does this mean that this tutorial in the first post doesn't work right?
Posted: Sun Aug 23, 2009 9:22 pm
by Electro
Team Xlink: correct
Posted: Sun Aug 23, 2009 10:17 pm
by Team Xlink
Electro wrote:Team Xlink: correct
Time to go dig through my source code to remove it or fix it then.
Posted: Sun Sep 20, 2009 2:43 am
by revelator
Code: Select all
// if there's only one then the list is already sorted!
if (cl_numvisedicts > 1)
{
// evaluate distances
for (i = 0; i < cl_numvisedicts; i++)
{
entity_t *ent = cl_visedicts[i];
// set distance from viewer - no need to sqrt them as the order will be the same
// (fixme - should we, and then subtract a radius?)
ent->alphadist = (ent->origin[0] - r_origin[0]) * (ent->origin[0] - r_origin[0]) + (ent->origin[1] - r_origin[1]) * (ent->origin[1] - r_origin[1]) + (ent->origin[2] - r_origin[2]) * (ent->origin[2] - r_origin[2]);
}
if (cl_numvisedicts == 2)
{
// trivial case - 2 entities
if (cl_visedicts[0]->alphadist < cl_visedicts[1]->alphadist)
{
entity_t *tmpent = cl_visedicts[1];
// reorder correctly
cl_visedicts[1] = cl_visedicts[0];
cl_visedicts[0] = tmpent;
}
}
else
{
// general case - depth sort the transedicts from back to front
qsort ((void *) cl_visedicts, cl_numvisedicts, sizeof (entity_t *), R_DepthSortEntities);
}
}
//Enable alpha blending
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
/* your drawing functions here */
//Disable alpha blending
glDisable(GL_BLEND);
seems to work. not sure if i need to depthcheck first ?
add float alphadist; to entity_t struct.
Re: Tutorial: Adding Alpha Transparency to stock GLQUAKE
Posted: Fri Apr 14, 2017 2:26 am
by revelator
Late as fuck to this one but better late than newer
the fullbright flag in nehahra has nothing at all to do with fullbrights its only use is the atom bomb effect from the demo movie that blanks the screen to white by turning of drawing brushmodels and letting the lightmap got all white. later versions of joequake does not even use it anymore i guess because it can do some nasty stuff to some mods that actually try to set a real fullbright value.
for those interested here it is in all its glory hackiness
Code: Select all
void R_RenderBrushPoly (msurface_t *fa)
{
texture_t *t;
byte *base;
int maps;
glRect_t *theRect;
int smax, tmax;
c_brush_polys++;
if (fa->flags & SURF_DRAWSKY)
{ // warp texture, no lightmaps
EmitBothSkyLayers (fa);
return;
}
t = R_TextureAnimation (fa->texinfo->texture);
GL_Bind (t->gl_texturenum);
if (fa->flags & SURF_DRAWTURB)
{ // warp texture, no lightmaps
EmitWaterPolys (fa);
return;
}
if (fa->flags & SURF_UNDERWATER)
DrawGLWaterPoly (fa->polys);
else
DrawGLPoly (fa->polys);
if (DoFullbright) return; // Ender: Fullbright this one. (revelator not as i understand fullbrights)
// add the poly to the proper lightmap chain
fa->polys->chain = lightmap_polys[fa->lightmaptexturenum];
lightmap_polys[fa->lightmaptexturenum] = fa->polys;
// check for lightmap modification
for (maps = 0 ; maps < MAXLIGHTMAPS && fa->styles[maps] != 255 ;
maps++)
if (d_lightstylevalue[fa->styles[maps]] != fa->cached_light[maps])
goto dynamic;
if (fa->dlightframe == r_framecount // dynamic this frame
|| fa->cached_dlight) // dynamic previously
{
dynamic:
if (r_dynamic.value && !r_fullbright.value)
{
lightmap_modified[fa->lightmaptexturenum] = true;
theRect = &lightmap_rectchange[fa->lightmaptexturenum];
if (fa->light_t < theRect->t) {
if (theRect->h)
theRect->h += theRect->t - fa->light_t;
theRect->t = fa->light_t;
}
if (fa->light_s < theRect->l) {
if (theRect->w)
theRect->w += theRect->l - fa->light_s;
theRect->l = fa->light_s;
}
smax = (fa->extents[0]>>4)+1;
tmax = (fa->extents[1]>>4)+1;
if ((theRect->w + theRect->l) < (fa->light_s + smax))
theRect->w = (fa->light_s-theRect->l)+smax;
if ((theRect->h + theRect->t) < (fa->light_t + tmax))
theRect->h = (fa->light_t-theRect->t)+tmax;
base = lightmaps + fa->lightmaptexturenum*lightmap_bytes*BLOCK_WIDTH*BLOCK_HEIGHT;
base += fa->light_t * BLOCK_WIDTH * lightmap_bytes + fa->light_s * lightmap_bytes;
R_BuildLightMap (fa, base, BLOCK_WIDTH*lightmap_bytes);
}
}
}
and here is where its set.
Code: Select all
void R_DrawBrushModel (entity_t *e)
{
int j, k;
vec3_t mins, maxs;
int i, numsurfaces;
msurface_t *psurf;
float dot;
mplane_t *pplane;
model_t *clmodel;
qboolean rotated;
float oldtexsort;
oldtexsort = gl_texsort.value;
currententity = e;
currenttexture = -1;
model_alpha = currententity->transparency;
if (model_alpha == 0)
model_alpha = 1;
clmodel = e->model;
if (e->angles[0] || e->angles[1] || e->angles[2])
{
rotated = true;
for (i=0 ; i<3 ; i++)
{
mins[i] = e->origin[i] - clmodel->radius;
maxs[i] = e->origin[i] + clmodel->radius;
}
}
else
{
rotated = false;
VectorAdd (e->origin, clmodel->mins, mins);
VectorAdd (e->origin, clmodel->maxs, maxs);
}
if (R_CullBox (mins, maxs))
return;
if (model_alpha != 1)
{
glEnable(GL_BLEND);
glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE); // TNT Fix
glColor4f (1,1,1, model_alpha);
Cvar_SetValue ("gl_texsort", 1);
}
else
glColor3f (1, 1, 1);
memset (lightmap_polys, 0, sizeof(lightmap_polys));
VectorSubtract (r_refdef.vieworg, e->origin, modelorg);
if (rotated)
{
vec3_t temp;
vec3_t forward, right, up;
VectorCopy (modelorg, temp);
AngleVectors (e->angles, forward, right, up);
modelorg[0] = DotProduct (temp, forward);
modelorg[1] = -DotProduct (temp, right);
modelorg[2] = DotProduct (temp, up);
}
psurf = &clmodel->surfaces[clmodel->firstmodelsurface];
// calculate dynamic lighting for bmodel if it's not an
// instanced model
if (clmodel->firstmodelsurface != 0 && !gl_flashblend.value)
{
for (k=0 ; k<MAX_DLIGHTS ; k++)
{
if ((cl_dlights[k].die < cl.time) ||
(!cl_dlights[k].radius))
continue;
R_MarkLights (&cl_dlights[k], 1<<k,
clmodel->nodes + clmodel->hulls[0].firstclipnode);
}
}
glPushMatrix ();
e->angles[0] = -e->angles[0]; // stupid quake bug
R_RotateForEntity (e, false);
e->angles[0] = -e->angles[0]; // stupid quake bug
if (psurf && psurf->polys) // This is probably not needed anymore
{
//
// draw texture
//
for (i=0 ; i<clmodel->nummodelsurfaces ; i++, psurf++)
{
// find which side of the node we are on
pplane = psurf->plane;
dot = DotProduct (modelorg, pplane->normal) - pplane->dist;
// draw the polygon
if (((psurf->flags & SURF_PLANEBACK) && (dot < -BACKFACE_EPSILON)) ||
(!(psurf->flags & SURF_PLANEBACK) && (dot > BACKFACE_EPSILON)))
{
if (e->fullbright == 1) DoFullbright = 1; // revelator: Zomg HACK
if (gl_texsort.value)
R_RenderBrushPoly (psurf);
else
R_DrawSequentialPoly (psurf);
DoFullbright = 0;
}
}
}
R_BlendLightmaps ();
glPopMatrix ();
if (model_alpha != 1)
{
Cvar_SetValue ("gl_texsort", oldtexsort);
glDisable(GL_BLEND);
}
}
Marked the fun stuff with my avatar name